I have many antique radios that will not keep a steady volume. Whenever a switch (fridge, light switch, washing machine, or other) is turned on or off these radios will jump up in volume. Could this be in the AGC? If so, what should I check? This happens in most of my superhedrodine radios but I can't think of any of my TRF units that have this problem. That is why I'm thinking AGC.

A V C (automatic volume control)

Actually what should happen is the radios should decrease in volume for a second. The loud "POP" of the switch or whatever turned on or off will create a signal stronger than the radio signal, which will create more negative voltage in the AVC system. This will momentarily reduce the sensitivity of the RF circuits. If you were to run an electric mixer with poor filtering, this would permanently reduce the radio's volume for the station being received, though the mixer's interferance would come in at the volume formerly heard with the station. When the mixer was turned off, the volume would return to normal. Fortunately, if you own 1950s or 1940s Sunbeam or Hamilton Beach mixers, they come equipped with fine radio interferance supression components. Either can run right next to an AM radio with no trouble.

Thomas

:A V C (automatic volume control)
:
:Actually what should happen is the radios should decrease in volume for a second. The loud "POP" of the switch or whatever turned on or off will create a signal stronger than the radio signal, which will create more negative voltage in the AVC system. This will momentarily reduce the sensitivity of the RF circuits. If you were to run an electric mixer with poor filtering, this would permanently reduce the radio's volume for the station being received, though the mixer's interferance would come in at the volume formerly heard with the station. When the mixer was turned off, the volume would return to normal. Fortunately, if you own 1950s or 1940s Sunbeam or Hamilton Beach mixers, they come equipped with fine radio interferance supression components. Either can run right next to an AM radio with no trouble.
:
:Thomas

If it would not be the AVC then do you have any idea what it could be?
Tom

It is the AVC. There is nothing wrong with any of your radios. Some of my radios increase in volume. Most decrease in volume. This is normal. Don't worry about it. Your TRF sets don't usually do this because most of them do not have an AVC circuit. TRF sets often would have the volume control up at the front of the set, say on the antenna or first RF tube. Super-heterodyne sets have the volume control after all of the RF stages. Because of this, there must be some means of automatic regulation so that the stages will not distort on strong stations. There actually are some benefits to the AVC circuit such as that it limits fading of distant stations (where they come and go and flutter), and also tends to make all stations at a similar volume so that local stations don't blare and distant stations are not extremely quiet. AVC also tends to reduce the amount of static heard on local stations by reducing the sensitivity of the radio to a level which the static is not heard (except for light switches and such).

If you wish you may check the AVC circuits in each of your radios. You would have to list the model numbers for me to point out the exact components used because there are many variations on the circuit, but a basic circuit that is common is to take a 2.2 meg resistor off of the high end of the volume control and feed it to some or all of the IF secondaries (except for the last one), and to the antenna coil secondary (or large loop in a loop antenna). The AVC circuit sends a negative voltage to all of these components which connect to the various control grids in each circuit. By throwing the grids more negative, sensitivity is reduced. Loud stations produce more of a negative voltage, which throws the grids more negative. You should also find a condenser or so in this circuit marked for .05 MFD or there-abouts. The resistor(s) should be on value +/- 15%. I don't like to allow 20% deviations, though sometimes this causes no harm. The condenser(s) should have ABSOLUTELY NO LEAKAGE. When you test a condenser of this small value, you use the most sensitive resistance check scale your meter has. It should be like X 10,000 or something like that, and your fingers should be able to make the meter move. Disconnect the .05 MFD condenser (one lead is fine) and connect the meter across the condenser. The meter should jump up just a tiny bit and then fall back down to EXACTLY WHERE IT STARTED. If you need to retest, reverse the meter leads so that you charge the condenser in the opposite direction (these condensers are not polarity sensitive like electrolytics). Watch the meter closely. Keep your fingers off of the test leads or anything else that may cause a false reading. If the condenser is at all leaky, this can cause the circuit (or any other circuit such a condenser is used in) to malfunction. It is easy to understand this when you consider that the AVC resistor is several million ohms. Several million ohms leakage in the condenser will reduce the amount of AVC voltage available.

Since all of your super-heterodynes do this, I wouldn't suspect any trouble. Honestly, this sounds like normal behavior. If you wish to test out the circuit in each, though, you may do so. The above tests for the resistor and condenser hold true for any other place in a radio where such components are used (as said before). Those tests are the pass/fail tests you should go by when checking any circuit in the radio.

Thomas

The superhets use the AC line as a artificial ground, whenever an appliance starts up it changes the effectiveness of the ground. This is normal, your radios are OK.

Dave

:The superhets use the AC line as a artificial ground, whenever an appliance starts up it changes the effectiveness of the ground. This is normal, your radios are OK.
:
:Dave

Thanks for the help Dave and Tom,
I would like to think that this is normal, but it is so extreme. Also after the "click" that makes the radio louder, the destortion is also less, not that it sounded bad before, it just sounds better after. Then the radio will slowly go back to the way it was untill the next "click". I can't think of any of my ac/dc radios that do this, but most of my 30's ac sets do. The one that I was working on over the weekend is a Crosley "super 11" But I also know that my Philco 89 does this real bad. I could list others but I'm at work now and can't remember the model #s. I'm sure that if I fix one I could fix all of them. On these radios all of the caps have been replaced with new ones, but I have not done much about checking the resistors. Guess I should start checking them. I like to use my radios, but this problem kills the joy. I can't help but think it is in the AVC, but could that make the distortion any more or less? I would not think so. If it is a bias resistor of some sort why would the value change when a light switch is turned on or off? It would need to change value to make a differance in volume would it not? what do you think? Thanks for any help

Tom

You should check resistors. The Super 11 is great, isn't it? I have one. I love the mirror dial. I also love how the 6C5G (I think that's the #) tubes are used for no more than detector and AVC circuits. My Super 11 works great, so you must have some trouble. Make sure that you replaced the condensers in the radios with 400 volt or better replacements. Check your resistors and be sure that they are not more than 15% off. Disconnect one lead when checking a resistor. I think I had some trouble with my Super 11 in the biasing department of the 6K5 audio tube. Try connecting a jumper from the first grid resistor to the chassis. The second resistor should go to the small wire wound resistor (this supplies a slightly negative voltage to the grid). If the tube is faulty (gassy or weak), this will cause trouble, too. I had both problems. Even though my resistors were not drifted, I found that making the above change improved matters My condensers were not leaky, either. I must have a problem somewhere in the set because I shouldn't have to make that change, but it worked and the set works wonderfully. Also, in this particular set, if you don't have a fresh 6K5 at hand, the 6Q7 will work in the 6K5 socket with no changes made. I currently have a 6Q7 in use in my radio because the 6K5 I bought for the radio I needed for another radio. The above resistor wiring change works equally well for both tubes.

I'll have to look at the schematic for the Philco 89 and see what I think could be wrong.

Thomas

The Philco 89 uses the same audio biasing techniques for the 1st audio tube as the Crosley Super 11 uses. This was actually a very common method used in the 1930s. On the #75 tube grid resistor system, try shunting from the first resistor to ground in this set as well (where the two meet). Use either a wire (on both this and the Super 11) or use a resistance of about 1 or 2 meg. Try either and note performance.

Honestly, though, all resistors and such throughout the set must be in good condition to ensure good performance. How are your voltages throughout these sets? Drifted resistors will affect voltages. Try replacing any suspicious tubes, though do not replace tubes just for the heck of it. If no change was noticed, put back in the original tube (unless it is obviously bad).

If your sets are getting louder and less distorted, then there is an obvious problem. The audio should not be distorted at all. This sounds like the 1st audio grid biasing trouble I had in my Crosley Super 11, but could be something different in each set. For optimum performance, though, all components must perform perfectly. Perfection was just as important then as it is now.

As for why most of your AC/DC sets do not have this trouble, well, if it is in fact due to the biasing technique used on the 1st audio tube, most AC/DC sets do not use this technique. They simply use a resistor of high resistance that goes from the grid to the same potential as the cathode of the tube. It is natural for electrons to collect on the grid of the tube as they flow from the cathode. If the resistance chosen is just right, a controlled amount of electrons will collect on the grid and will automatically bias it negative without any external negative source. Excess electrons will leak off to ground.

Thomas

:The Philco 89 uses the same audio biasing techniques for the 1st audio tube as the Crosley Super 11 uses. This was actually a very common method used in the 1930s. On the #75 tube grid resistor system, try shunting from the first resistor to ground in this set as well (where the two meet). Use either a wire (on both this and the Super 11) or use a resistance of about 1 or 2 meg. Try either and note performance.
:
:Honestly, though, all resistors and such throughout the set must be in good condition to ensure good performance. How are your voltages throughout these sets? Drifted resistors will affect voltages. Try replacing any suspicious tubes, though do not replace tubes just for the heck of it. If no change was noticed, put back in the original tube (unless it is obviously bad).
:
:If your sets are getting louder and less distorted, then there is an obvious problem. The audio should not be distorted at all. This sounds like the 1st audio grid biasing trouble I had in my Crosley Super 11, but could be something different in each set. For optimum performance, though, all components must perform perfectly. Perfection was just as important then as it is now.
:
:As for why most of your AC/DC sets do not have this trouble, well, if it is in fact due to the biasing technique used on the 1st audio tube, most AC/DC sets do not use this technique. They simply use a resistor of high resistance that goes from the grid to the same potential as the cathode of the tube. It is natural for electrons to collect on the grid of the tube as they flow from the cathode. If the resistance chosen is just right, a controlled amount of electrons will collect on the grid and will automatically bias it negative without any external negative source. Excess electrons will leak off to ground.
:
:Thomas

Thanks for all the help, Yes that super 11 is something else. When I got it it was in very bad shape (mice damage and all) but after refinishing it,it looks great. I will check the things that you said and see how it goes. I will have to work on the Philco later but I do think that the problem is something that is in common with the two radios.
Thanks again, Tom

My Super 11 was the same. I used to work for my city's highway department several years ago when I was 19 and 20 (summer job). The guys knew I was into repairing old radios and saw me bring a chassis back to life from a radio that was completely trash that someone threw out. I brought in a stack of Glenn Miller records and played them on this thing. They thought it was awesome. It was an RCA Victrola from about 1941 and used a chassis similar to the 16T3 table model. I still have the chassis, which I gutted, and am going to make into a kit radio for a nephew of mine after I get done cleaning all of the parts and making them look like new. Then I have to make a really nice cabinet. I'm thinking like the Airline 62-306 cabinet.

Anyway, the fall after the last year I worked for the city, one day I found this big old nasty radio in my driveway. The brass was tarnished. The chassis and cabinet were yellow with cigarette smoke. The veneer was falling off all over and was chipped. I almost threw it away, especially since I live with my parents. My mom freaked! Well, First I cleaned up the cabinet with furniture soap, and then polished the brass (this made a huge difference), and then got the chassis going. It started looking good, especially with that deep bass. Over the course of two years I replaced bad veneers and refinished it. The cabinet required glue injection all over the place to make it solid again. I even had to make a center speaker grill piece with my dad because one was missing. It looks just like the original! The chassis shines and the interior is painted satin black. Looks great! All of the right places on the front have the appropriate shade of colored varnish (maroon-jet mahogany and walnut). The grill cloth on this radio is fantastic. I haven't seen another with this cloth. It's a striking leaf in relief type triangle pattern. It's really art deco! Noone makes it, either. Mine's faded, but originally it was gold on dark brown or gold on black, and this would be fantastic. I am never going to replace the cloth on this radio even though it is faded and old. Some day when I actually have some money, I'm going to have some custom made. It is striking and I don't know why on earth noone makes it.

By the way, once you get your Super 11 working properly, bass kicks it out twice as much when you use 6V6G tubes in place of the 6K6G tubes, though it may be a bit too much. You may try using a 6V6G in the first socket (end of chassis), and use a 6F6G or 6K6G in the socket next to it. The 6V6G also brings forth more of the high frequency notes like the sharp trumpets and stringy violins. This amplifier benefits from a special negative feedback system that I derived.

I also came up with improvements to the AVC circuit to both make the eye tube more responsive and make the system respond more. This improvement is not necessary at all, though. The radio works extremely well without it.

By the way, on your short wave band (foreign--F), do you pick up FM stations at the high end from about 15 MC on up? I do. I think something is not operating properly. They are not detected properly, and are all distorted because of the AM detection system. They're like harmonics or something because all of the stations across the FM dial repeat over and over again, along with some television stations, and not necessarily in order. Some day I'm going to completely go over the electronics inside the radio. For now I just use it and enjoy it. It's incredibly sensitive. By the way, your Super 11 will operate best when used with a V-Doublet antenna such as that listed in the General Electric section of the Resources section of this web page. Use 300 ohm flat television lead-in wire for the lead-in. Your reception will be static free with this antenna.

Thomas

:My Super 11 was the same. I used to work for my city's highway department several years ago when I was 19 and 20 (summer job). The guys knew I was into repairing old radios and saw me bring a chassis back to life from a radio that was completely trash that someone threw out. I brought in a stack of Glenn Miller records and played them on this thing. They thought it was awesome. It was an RCA Victrola from about 1941 and used a chassis similar to the 16T3 table model. I still have the chassis, which I gutted, and am going to make into a kit radio for a nephew of mine after I get done cleaning all of the parts and making them look like new. Then I have to make a really nice cabinet. I'm thinking like the Airline 62-306 cabinet.
:
:Anyway, the fall after the last year I worked for the city, one day I found this big old nasty radio in my driveway. The brass was tarnished. The chassis and cabinet were yellow with cigarette smoke. The veneer was falling off all over and was chipped. I almost threw it away, especially since I live with my parents. My mom freaked! Well, First I cleaned up the cabinet with furniture soap, and then polished the brass (this made a huge difference), and then got the chassis going. It started looking good, especially with that deep bass. Over the course of two years I replaced bad veneers and refinished it. The cabinet required glue injection all over the place to make it solid again. I even had to make a center speaker grill piece with my dad because one was missing. It looks just like the original! The chassis shines and the interior is painted satin black. Looks great! All of the right places on the front have the appropriate shade of colored varnish (maroon-jet mahogany and walnut). The grill cloth on this radio is fantastic. I haven't seen another with this cloth. It's a striking leaf in relief type triangle pattern. It's really art deco! Noone makes it, either. Mine's faded, but originally it was gold on dark brown or gold on black, and this would be fantastic. I am never going to replace the cloth on this radio even though it is faded and old. Some day when I actually have some money, I'm going to have some custom made. It is striking and I don't know why on earth noone makes it.
:
:By the way, once you get your Super 11 working properly, bass kicks it out twice as much when you use 6V6G tubes in place of the 6K6G tubes, though it may be a bit too much. You may try using a 6V6G in the first socket (end of chassis), and use a 6F6G or 6K6G in the socket next to it. The 6V6G also brings forth more of the high frequency notes like the sharp trumpets and stringy violins. This amplifier benefits from a special negative feedback system that I derived.
:
:I also came up with improvements to the AVC circuit to both make the eye tube more responsive and make the system respond more. This improvement is not necessary at all, though. The radio works extremely well without it.
:
:By the way, on your short wave band (foreign--F), do you pick up FM stations at the high end from about 15 MC on up? I do. I think something is not operating properly. They are not detected properly, and are all distorted because of the AM detection system. They're like harmonics or something because all of the stations across the FM dial repeat over and over again, along with some television stations, and not necessarily in order. Some day I'm going to completely go over the electronics inside the radio. For now I just use it and enjoy it. It's incredibly sensitive. By the way, your Super 11 will operate best when used with a V-Doublet antenna such as that listed in the General Electric section of the Resources section of this web page. Use 300 ohm flat television lead-in wire for the lead-in. Your reception will be static free with this antenna.
:
:Thomas

Thomas, I will check to see if I get any FM this weekend but I don't think so. Also I could not find the info on the V-doublet antenna, can you redirect me?

::My Super 11 was the same. I used to work for my city's highway department several years ago when I was 19 and 20 (summer job). The guys knew I was into repairing old radios and saw me bring a chassis back to life from a radio that was completely trash that someone threw out. I brought in a stack of Glenn Miller records and played them on this thing. They thought it was awesome. It was an RCA Victrola from about 1941 and used a chassis similar to the 16T3 table model. I still have the chassis, which I gutted, and am going to make into a kit radio for a nephew of mine after I get done cleaning all of the parts and making them look like new. Then I have to make a really nice cabinet. I'm thinking like the Airline 62-306 cabinet.
::
::Anyway, the fall after the last year I worked for the city, one day I found this big old nasty radio in my driveway. The brass was tarnished. The chassis and cabinet were yellow with cigarette smoke. The veneer was falling off all over and was chipped. I almost threw it away, especially since I live with my parents. My mom freaked! Well, First I cleaned up the cabinet with furniture soap, and then polished the brass (this made a huge difference), and then got the chassis going. It started looking good, especially with that deep bass. Over the course of two years I replaced bad veneers and refinished it. The cabinet required glue injection all over the place to make it solid again. I even had to make a center speaker grill piece with my dad because one was missing. It looks just like the original! The chassis shines and the interior is painted satin black. Looks great! All of the right places on the front have the appropriate shade of colored varnish (maroon-jet mahogany and walnut). The grill cloth on this radio is fantastic. I haven't seen another with this cloth. It's a striking leaf in relief type triangle pattern. It's really art deco! Noone makes it, either. Mine's faded, but originally it was gold on dark brown or gold on black, and this would be fantastic. I am never going to replace the cloth on this radio even though it is faded and old. Some day when I actually have some money, I'm going to have some custom made. It is striking and I don't know why on earth noone makes it.
::
::By the way, once you get your Super 11 working properly, bass kicks it out twice as much when you use 6V6G tubes in place of the 6K6G tubes, though it may be a bit too much. You may try using a 6V6G in the first socket (end of chassis), and use a 6F6G or 6K6G in the socket next to it. The 6V6G also brings forth more of the high frequency notes like the sharp trumpets and stringy violins. This amplifier benefits from a special negative feedback system that I derived.
::
::I also came up with improvements to the AVC circuit to both make the eye tube more responsive and make the system respond more. This improvement is not necessary at all, though. The radio works extremely well without it.
::
::By the way, on your short wave band (foreign--F), do you pick up FM stations at the high end from about 15 MC on up? I do. I think something is not operating properly. They are not detected properly, and are all distorted because of the AM detection system. They're like harmonics or something because all of the stations across the FM dial repeat over and over again, along with some television stations, and not necessarily in order. Some day I'm going to completely go over the electronics inside the radio. For now I just use it and enjoy it. It's incredibly sensitive. By the way, your Super 11 will operate best when used with a V-Doublet antenna such as that listed in the General Electric section of the Resources section of this web page. Use 300 ohm flat television lead-in wire for the lead-in. Your reception will be static free with this antenna.
::
::Thomas
:
:
:Thomas, I will check to see if I get any FM this weekend but I don't think so. Also I could not find the info on the V-doublet antenna, can you redirect me?
:
:One other thing, do you find that voltages that are tested are lower than what is listed in the schematics? Not just in the super 11 but other radios also? About 20% lower

As for the voltages, if your voltages are lower, check all of your power resistors. For the Super 11, there should be a drop of about 60 volts across the field. If the drop is more or less, as long as the field reads proper resistance (disconnected), then your trouble lies elsewhere. Electrolytics should be in good condition (meter on most sensitive setting...like X10,000...should go to zero and then fall back to infinity). Check your power transformer voltages (AC) both with and without the rectifier in place. My Super 11 originally had a bad power transformer. It would get REALLY hot and smell bad after about 20 minutes of operation. I have since replaced it. My current transformer, one that I had at hand, puts out 400 volts. I put a ballast resistor in series with the field prior to the field, so all of my voltages are right on. I chose a ballast resistor that would yield proper voltages. Make sure that all of your paper condensers are not leaky (if you haven't already replaced them). If they are leaky, such as those in the bypass and tone sections of the audio, or those that filter the screen grid voltage to the various RF tubes, they will bring the B current down somewhat. A comprehensive list of actual voltages found vs. what should be there would tell both you and me what is going on where (if just the B voltages are down or if all the voltages are down--filament, etc.).

When measuring resistances and checking for leakage in condensers, disconnect one of the two leads of the component in question. Some people like to take resistances by leaving the component wired to the radio. This is poor practice and will give you meaningless answers. Other than electrolytics, which can have a fairly acceptable leakage of 10 meg, condensers should have NO leakage, not 10 meg, not 100 meg, not anything. The leakages shown above are not those that will bog down your power supply (you'll need a much higher rate of leakage for this), but they will affect the performance of your radio in other ways. Tubes are high impedance devices and are sensitive to extremely small things. Though they are huge and impractical for modern transistor applications, they are far more sensitive than modern integrated circuitry. With such high impedances, it is easy to see how a small amount of B+ leaking through an audio bypass condenser can throw off the negative grid bias of the succeeding tube. For perfect performance, you must have perfect components.

As for the FM in the short wave, this is just a phenomenon I noticed in my set. If you do or do not notice it in your set, it is not a huge deal. Someone altered the oscillator coil for the short wave in my Super 11, and furthermore it was open when I received the set. The coil wasn't electrically altered, but physically moved along with the corresponding trimmer, which may or may not affect performance. I mended the coil without altering it electrically.

As for the V-Doublet antenna, go to the Resources section of this web site--above menu, and then go to General Electric (not General Electric Canadian). Scroll down the model numbers and you will come to V-DOUBLET. This explains a V-doublet antenna that they sold and gives you a general idea as to how to build yours. Each horizontal half may be from 20 to 30 feet in length, maybe even longer. Certain lengths cause certain dead spots on the dial. The article goes into some detail about this, and if you worked out the math you could figure out what the proper length would be. I've never done this. I used about 25 feet for each side and it works well for most wavelengths. Join the two wires in the center with an insulator so that they DO NOT connect electrically. Then, about 2 to 3 feet out from center on each side, connect a 3 to 4 foot wire. Bring each of these wires together to the center to form a V, and solder each to each lead of your 300 ohm flat twin lead television lead-in wire. Tape with friction tape or use heat shrink. Using about 50 to 100 feet of the flat twin lead, connect the other end to the two antenna terminals on your Super 11. In most cases, unless you have a lot of dimmers and fluorescents in your house, your reception will be practically static free. It's amazing! The flat twin lead also fits nicely under windows, so there is no need for special lead-in straps.

Keep in mind that certain parts of the short wave band are more receivable during certain times of the day. For instance, here in Milwaukee, from about 6 MC to 20 MC I find lots of stations in the day, but the band from 1.8 to 6 MC is fairly dead except for the broadcast stations down around 1.8 MC. At night this switches around to some degree, though many stations still remain on the higher band. This does not constitute dead spots. The only way to test your receiver for dead spots would be to theoretically calculate the different antenna lengths that would create wave cancellations or would not harmonize well with certain wavelengths, or to actually test the radio's reception with a local transmitter that was capable of transmitting many different frequencies, one at a time. Unless you are really into short wave, this isn't really necessary.

Thomas

:As for the voltages, if your voltages are lower, check all of your power resistors. For the Super 11, there should be a drop of about 60 volts across the field. If the drop is more or less, as long as the field reads proper resistance (disconnected), then your trouble lies elsewhere. Electrolytics should be in good condition (meter on most sensitive setting...like X10,000...should go to zero and then fall back to infinity). Check your power transformer voltages (AC) both with and without the rectifier in place. My Super 11 originally had a bad power transformer. It would get REALLY hot and smell bad after about 20 minutes of operation. I have since replaced it. My current transformer, one that I had at hand, puts out 400 volts. I put a ballast resistor in series with the field prior to the field, so all of my voltages are right on. I chose a ballast resistor that would yield proper voltages. Make sure that all of your paper condensers are not leaky (if you haven't already replaced them). If they are leaky, such as those in the bypass and tone sections of the audio, or those that filter the screen grid voltage to the various RF tubes, they will bring the B current down somewhat. A comprehensive list of actual voltages found vs. what should be there would tell both you and me what is going on where (if just the B voltages are down or if all the voltages are down--filament, etc.).
:
:When measuring resistances and checking for leakage in condensers, disconnect one of the two leads of the component in question. Some people like to take resistances by leaving the component wired to the radio. This is poor practice and will give you meaningless answers. Other than electrolytics, which can have a fairly acceptable leakage of 10 meg, condensers should have NO leakage, not 10 meg, not 100 meg, not anything. The leakages shown above are not those that will bog down your power supply (you'll need a much higher rate of leakage for this), but they will affect the performance of your radio in other ways. Tubes are high impedance devices and are sensitive to extremely small things. Though they are huge and impractical for modern transistor applications, they are far more sensitive than modern integrated circuitry. With such high impedances, it is easy to see how a small amount of B+ leaking through an audio bypass condenser can throw off the negative grid bias of the succeeding tube. For perfect performance, you must have perfect components.
:
:As for the FM in the short wave, this is just a phenomenon I noticed in my set. If you do or do not notice it in your set, it is not a huge deal. Someone altered the oscillator coil for the short wave in my Super 11, and furthermore it was open when I received the set. The coil wasn't electrically altered, but physically moved along with the corresponding trimmer, which may or may not affect performance. I mended the coil without altering it electrically.
:
:As for the V-Doublet antenna, go to the Resources section of this web site--above menu, and then go to General Electric (not General Electric Canadian). Scroll down the model numbers and you will come to V-DOUBLET. This explains a V-doublet antenna that they sold and gives you a general idea as to how to build yours. Each horizontal half may be from 20 to 30 feet in length, maybe even longer. Certain lengths cause certain dead spots on the dial. The article goes into some detail about this, and if you worked out the math you could figure out what the proper length would be. I've never done this. I used about 25 feet for each side and it works well for most wavelengths. Join the two wires in the center with an insulator so that they DO NOT connect electrically. Then, about 2 to 3 feet out from center on each side, connect a 3 to 4 foot wire. Bring each of these wires together to the center to form a V, and solder each to each lead of your 300 ohm flat twin lead television lead-in wire. Tape with friction tape or use heat shrink. Using about 50 to 100 feet of the flat twin lead, connect the other end to the two antenna terminals on your Super 11. In most cases, unless you have a lot of dimmers and fluorescents in your house, your reception will be practically static free. It's amazing! The flat twin lead also fits nicely under windows, so there is no need for special lead-in straps.
:
:Keep in mind that certain parts of the short wave band are more receivable during certain times of the day. For instance, here in Milwaukee, from about 6 MC to 20 MC I find lots of stations in the day, but the band from 1.8 to 6 MC is fairly dead except for the broadcast stations down around 1.8 MC. At night this switches around to some degree, though many stations still remain on the higher band. This does not constitute dead spots. The only way to test your receiver for dead spots would be to theoretically calculate the different antenna lengths that would create wave cancellations or would not harmonize well with certain wavelengths, or to actually test the radio's reception with a local transmitter that was capable of transmitting many different frequencies, one at a time. Unless you are really into short wave, this isn't really necessary.
:
:Thomas

Thomas, Thanks for the help, I found the antenna info I don't know why I did not see it the first time. I could not do much "work" on radios last weekend I had some plumbing problems in the house so maybe next weekend. I did try the shortwave on the Super 11 and I can't say I get any FM or TV on that band, so it must be due to the mods on your set. I think you are right, I must get serious and check ALL voltages to find out why the B+ is low in some of my radios, My problem is that I have had NO training in radio repair, All I have done is to buy just about every book on the topic then buy radios and make them work. Most of the time that means just replace all caps, the bad thing is that this will make the radio work but it may not work as good as it can. I do have some old (60's) signal generators and I have gotten into alignment somewhat. I have a moderen 25mhz 'scope but I find it does not help much, I think I know what I'm looking at but if I don't get the waveform that I think should be, and tubes are good, caps are new and I have B+, I don't know what to do. Like this one radio I have, a Philco 42-345, a table unit with broadcast, police and SW bands, it works on all bands but the SW band. It has no IF waveform on SW it has good waveform on b'cast and a little lower on police but flat line on SW I checked all band switch contacts and coils, all seem good. I put he radio back together, refinished the cabnet and put it on the shelf, someday I will learn something and can go back to it.

Tom

You will learn with time. Just to clue you in, I was never trained. I trained myself. First, when I was young, I took radios apart. I plugged tubes into different sockets, blew things up, and was disappointed with what I did. Then, around 12 or 13, I was able to make radios work by replacing the tubes I blew out (AC-DC sets). The radios had previously worked. Then by 15 I was building regenerative sets and amplifiers. I built a really nice amplifier using an 80, 2A3, and 57, by reading the diagram of a gutted Magnavox phonograph we had lying around. As time went on I figured more and more out. I'm 25 now and am still learning, but I've come a long way. It helps that I started young, as I had loads of time to fool around with stuff. Now, with college and a crappy job, I don't have that time anymore. Still, when I get the chance to read old books on radio, I soak up as much information as I can. I understand most of what goes on, but I read it anyway because every now and then I catch something new. I've also been reading up on television for the last few years. It isn't that complicated, but it sure makes my head spin. All of the sync pulses and stuff that are broadcast all together and how it's all filtered out and separated amazes me. I understand it, but it's crazy.

Just read and you will get it with time. You must be able to visualize it and understand that electricity is just like any other matter, such as water or air. It has the same properties and a few extras. The notion that electricity is energy is misleading. Electricity posesses certain energies like magnetism, but it is just a form of matter. It is moved by energy but it is not energy in itself. The energy that moves electricity and water and air is not at all understood really. Understanding that electricity is simply the matter that is moved by energy will allow you to understand the different circuits and frequencies and various other properties.

Anyway, bla bla bla.

Thomas

P.S. That the short wave band produces no IF activity means that something is either faulty in the short wave oscillator or antenna circuit (unless something else in the radio is causing these circuits to not function properly--power supply, AVC, etc.). Check for an open coil (or possibly shorted, though not usually likely), shorted condenser (or open on rare occasion), wire, gassy or weak tube, or mis-adjusted circuit. Short wave can be incredibly hard to align. It is extremely sensitive, almost as much as high frequency FM. Also, though this is not all that is required to bring a radio up to optimum condition, replacing condensers is one of the steps. Simply replacing all of the condensers as you say you have done is perfectly fine and can yield a wonderfully performing radio. Going around and testing the old condensers for leakage will teach you things--such as what caused what problem. Skipping this process and simply replacing all of the condensers WILL bring that part of the radio up to optimum condition. Whenever someone comes on here with a problem that may involve a condenser, I always emphasize testing the condensers simply because this process allows you to learn what is going on inside your radio and why something went wrong. If you want to skip this process and simply replace all parts that are most likely to fail (condensers and resistors), you are no less likely to have a superbly performing radio, provided that you align it properly, etc., but skipping this process teaches you nothing. In the end, after you have tested all of the condensers and learned a few things about what improvements were made by replacing certain condensers, you may go and replace all of them anyway (this is a safe idea because old condensers like to fail one after another). The neat thing about testing them and replacing only those that you suspect to be bad (for the time being) is that you learn what problem caused what, and then when you get another radio that has the same problem, you know just where to go.

Thomas, sounds like that old Magnavox with the 80, 2A3, and 57 was the Model 120A. I've got a light oak Magnavox phono, Model 120A, Style P103-1 with AMP 120 and those tubes.

:You will learn with time. Just to clue you in, I was never trained. I trained myself. First, when I was young, I took radios apart. I plugged tubes into different sockets, blew things up, and was disappointed with what I did. Then, around 12 or 13, I was able to make radios work by replacing the tubes I blew out (AC-DC sets). The radios had previously worked. Then by 15 I was building regenerative sets and amplifiers. I built a really nice amplifier using an 80, 2A3, and 57, by reading the diagram of a gutted Magnavox phonograph we had lying around. As time went on I figured more and more out. I'm 25 now and am still learning, but I've come a long way. It helps that I started young, as I had loads of time to fool around with stuff. Now, with college and a crappy job, I don't have that time anymore. Still, when I get the chance to read old books on radio, I soak up as much information as I can. I understand most of what goes on, but I read it anyway because every now and then I catch something new. I've also been reading up on television for the last few years. It isn't that complicated, but it sure makes my head spin. All of the sync pulses and stuff that are broadcast all together and how it's all filtered out and separated amazes me. I understand it, but it's crazy.
:
:Just read and you will get it with time. You must be able to visualize it and understand that electricity is just like any other matter, such as water or air. It has the same properties and a few extras. The notion that electricity is energy is misleading. Electricity posesses certain energies like magnetism, but it is just a form of matter. It is moved by energy but it is not energy in itself. The energy that moves electricity and water and air is not at all understood really. Understanding that electricity is simply the matter that is moved by energy will allow you to understand the different circuits and frequencies and various other properties.
:
:Anyway, bla bla bla.
:
:Thomas
:
:P.S. That the short wave band produces no IF activity means that something is either faulty in the short wave oscillator or antenna circuit (unless something else in the radio is causing these circuits to not function properly--power supply, AVC, etc.). Check for an open coil (or possibly shorted, though not usually likely), shorted condenser (or open on rare occasion), wire, gassy or weak tube, or mis-adjusted circuit. Short wave can be incredibly hard to align. It is extremely sensitive, almost as much as high frequency FM. Also, though this is not all that is required to bring a radio up to optimum condition, replacing condensers is one of the steps. Simply replacing all of the condensers as you say you have done is perfectly fine and can yield a wonderfully performing radio. Going around and testing the old condensers for leakage will teach you things--such as what caused what problem. Skipping this process and simply replacing all of the condensers WILL bring that part of the radio up to optimum condition. Whenever someone comes on here with a problem that may involve a condenser, I always emphasize testing the condensers simply because this process allows you to learn what is going on inside your radio and why something went wrong. If you want to skip this process and simply replace all parts that are most likely to fail (condensers and resistors), you are no less likely to have a superbly performing radio, provided that you align it properly, etc., but skipping this process teaches you nothing. In the end, after you have tested all of the condensers and learned a few things about what improvements were made by replacing certain condensers, you may go and replace all of them anyway (this is a safe idea because old condensers like to fail one after another). The neat thing about testing them and replacing only those that you suspect to be bad (for the time being) is that you learn what problem caused what, and then when you get another radio that has the same problem, you know just where to go.

Well, the schematic that is exactly like mine is listed here as A-501B. A-501 is also the same electrically, but is drawn slightly differently. The A-501B looks exactly like the one in my phonograph. I have never found anything on this phonograph. I would love to build it back to original, but I have never seen another one. On the rear it says model 3B (or 4B..I forgot). It is from the Electro-Acoustic Division. It is in my room and I have to fly to work (sux!), so I'll go check later. Love it, though. That amplifier has a LOT of power for its size. The sound is incredible, too. Who thought something could be so simple and so good sounding. When I built it, though, I used a condenser more like .01 or .05 MFD from the screen of the 57 to the plate of the 2A3. Forgot exactly what I used...don't know if I used the resistor, too, or omitted it. I fooled around with those two components, though, and got some amazing sounds. The original set-up of those two components as stated in the schematic didn't really do much and I didn't like the sound. Anyway...that's the info I have. Wish I had more. Send me a picture if you like. My e-mail is connected to my name above at left.

Thomas

:Thomas, sounds like that old Magnavox with the 80, 2A3, and 57 was the Model 120A. I've got a light oak Magnavox phono, Model 120A, Style P103-1 with AMP 120 and those tubes.

I want just add to all the right subjets we read, that It may happens that a innocent light opened condenser on the antenna tap wire may be causes defectives and sudden "POP" fail in the volume.I should be to check it before find pretendy guilties components into AVC circuit.