I'm having a hard time getting my Atwater Kent model 10C to work. Tested all tubes, all good. went through the troubleshooting tests from the Atwater site that runs you through tests like...Black battery connection wire to F terminal of 1st RF tube...2ond Rf tube etc.. checking for opens of shorts. Long story short all tested good after I found a shorted by-pass cap and replaced that. Now still will not work. Back around Christmas I posted a question about auido transformers, and I have replaced both of them. When I inject a signal to the detector I get that auido out the speaker, so my detector and auido amps are working. Next step-- inject signal to the grid of the 2ond RF tube, again good signal out the speaker/horn. moving on to the grid of the 1st RF tube i get no or very, very weak sound out of the speaker. So somthing is amiss with the 1st Rf section. I have checked the windings on the RF coil between the 1st and 2ond RF amps and have found no open coil.
I know I'm just missing something very easy to find but just can not find it, that explains the subject line of this post.
thanks for any help
Tom

Check the 2-4 megohm grid leak resistor. It should be within that range. Inject a signal at the previous tube's plate through a .001 MFD capacitor. Connect the other end of your generator to B-. Use the resistance that gives the loudest audio signal. If you can get the signal to go through from the antenna terminal, inject there instead.

Once you are sure that the grid leak works as it should, start at the antenna with your generator. Inject a signal. If the tuning capacitors have trimmers, adjust each one for maximum gain. If not, you may have to adjust by other means. For starters, if the stators can be moved by loosening screws, center all stators. As an example, when I first got my Radiola 16 (Peter gave it to me), it wouldn't pick up anything. The stators weren't centered. No other means of fine tuning was provided in the set, so in order to get all stages to track similarily, I had to center the stators and then work from there.

Once you have maximum gain, connect a 10 foot or longer antenna wire and try the set out. If you still can't pull in signals well, be sure that the A battery is connected properly. Try reversing it. Strange as it may seem, the tubes and their circuitry are designed in such a way that they work best with the A battery connected one way verses another. When you think about it you'll realize that the A battery makes one side of the filament more negative than the other, which affects grid bias. Everything is designed with that in mind.

Finally, if you can't get your set to work properly, take out the 01A tubes and test them. If they test weak, run the filaments very briefly at 7.5 volts (if your tester has such a setting....if not, run at 6.3 with the LINE adjuster turned all the way up). Then, after about 3 seconds have passed, turn the filament voltage down to 6.3. Run the filament that way for at least 15 minutes. You can test to see if any improvements are being made after 5 minutes. Once you are done, the tubes should test much better. This rejuvenation procedure made a big difference in my set's performance.

Be sure that you are feeding the filaments proper voltage while operating your radio. A small decrease in voltage with thoriated tungsten filaments makes a big difference in performance. You should be reading 5.0 volts at the sockets. Of course be sure that your rheostats are adjusted properly. They are there for volume control purposes, but should be adjusted for 5.0 volts for initial tests.

T.

Thanks for the reply, I checked the grid leak as I put the radio bac together, and replaced it. he radio works fine from the grid of the detector. the problem is in the 1st RF amp or the 2ond RF coil. I just can not find any open coil.I have correct voltage at filaments, Tubes all test good I'm going to do some more testing on it right now, thanks for the help
Tom

:Check the 2-4 megohm grid leak resistor. It should be within that range. Inject a signal at the previous tube's plate through a .001 MFD capacitor. Connect the other end of your generator to B-. Use the resistance that gives the loudest audio signal. If you can get the signal to go through from the antenna terminal, inject there instead.
:
:Once you are sure that the grid leak works as it should, start at the antenna with your generator. Inject a signal. If the tuning capacitors have trimmers, adjust each one for maximum gain. If not, you may have to adjust by other means. For starters, if the stators can be moved by loosening screws, center all stators. As an example, when I first got my Radiola 16 (Peter gave it to me), it wouldn't pick up anything. The stators weren't centered. No other means of fine tuning was provided in the set, so in order to get all stages to track similarily, I had to center the stators and then work from there.
:
:Once you have maximum gain, connect a 10 foot or longer antenna wire and try the set out. If you still can't pull in signals well, be sure that the A battery is connected properly. Try reversing it. Strange as it may seem, the tubes and their circuitry are designed in such a way that they work best with the A battery connected one way verses another. When you think about it you'll realize that the A battery makes one side of the filament more negative than the other, which affects grid bias. Everything is designed with that in mind.
:
:Finally, if you can't get your set to work properly, take out the 01A tubes and test them. If they test weak, run the filaments very briefly at 7.5 volts (if your tester has such a setting....if not, run at 6.3 with the LINE adjuster turned all the way up). Then, after about 3 seconds have passed, turn the filament voltage down to 6.3. Run the filament that way for at least 15 minutes. You can test to see if any improvements are being made after 5 minutes. Once you are done, the tubes should test much better. This rejuvenation procedure made a big difference in my set's performance.
:

:Be sure that you are feeding the filaments proper voltage while operating your radio. A small decrease in voltage with thoriated tungsten filaments makes a big difference in performance. You should be reading 5.0 volts at the sockets. Of course be sure that your rheostats are adjusted properly. They are there for volume control purposes, but should be adjusted for 5.0 volts for initial tests.
:
:T.

Did you check the other things I listed??????????????????????????????????????????????????????????????????????????????????

T.

Thomas,
Thanks for the help, Yes I have a more than 10 foot antenna hooked up, Like I said the grid leak is good and correct, "A" battery is hooked up correctly, I did not try to reverse the "A" battery, All tubes were tested on an Eico 666 tester and all test good and my home built power supply gives 5.6 volts "A" output with the tubes powered up. This power supply powers my Fada 175 5 tube TRF radio fine.
Now let me tell you what I found out last night, IT WORKS! I tried it again by injecting a signal at the detector grid-got sound out of the horn, inject signal at plate of 2ond RF tube-got sound out of horn, injected signal at grid of 2ond RF tube-got sound out, injected signal at plate of 1st RF tube-got sound out, injected signal at grid of 1st RF tube-got sound out!! This is the first time I got any output when the injected signal was injected before the 1st RF tube. So what was wrong? The only thing I can think of is that the grid or plate pin of the tube that was in that position was not making contact. I did clean/polish the spring contacts in all the tube sockets but I did not clean the pins on the tubes yet. This radio has the tube sockets that just make contact with the pins at the tip end of the pins.
The problem I have now is that the radio is not quite as good as my Fada T.R.F. it can pick up many stations but they don't come in very well and they are all compacted close together, all between 0 and 40 on the dials. As you know on the old breadboards the dials were not marked off in khz but just in a scale of 0 to 100. Do you have any ideas as to what would cause this? My antenna is about 15 feet of wire strung up in the ceiling of my basement so it is only about 2-3 feet above ground- not the best for an old 1924 radio but would this cause the stations to be compacted so close together?
thanks again,
Tom

:Did you check the other things I listed??????????????????????????????????????????????????????????????????????????????????
:
:T.

A radio of poor design might have all the stations compacted together. I have heard that Atwater Kent made fine radios. I am assuming that 0-40 is maximum capacitance. If so, then either the coils are too small, or the capacitors need parallel capacitance to broaden their tuning. If 0-40 is in the minimum capacitance range, then either your stators are too close to your rotors, or parallel trimmer capacitors are set up too tightly, causing stations to not tune in until capacitance is reduced significantly. Parallel capacitance tends to affect the high frequency end more than the low frequency end, so stations shouldn't be too crammed at the low end.

Tom,
Try changing the antenna tap switch - located to the far left of the radio and on top of the antenna coil. Here's what's in the operating instructions for the 10B....

"The same insructions apply to these sets as to the foregoing Models 10 and 10-A, excepting that these later sets are equipped with the 3-point antenna tap switch. For most purposes this should be set at the center point. For stations below 20 on the dial, the first or nearest point should be used.The 3rd or farthest point may be useful when a very short antenna is used, or for reception of the higher wavelength stations. A change in the position of this switch requires a readjustment of the first or left hand dial."

You might want to look for a repro of the operating instructions as it gives you approximate dial settings

Sounds like the antenna fine tuning control on my Majestic 180. However, that control is continuous. What it does is raise or lower a copper bell over the antenna coil. It's very responsive (unless the control is operated, you might not receive stations on certain parts of the dial).

T.

Tom,

Try changing the antenna tap switch - located to the far left of the radio and on top of the antenna coil. Here's what's in the operating instructions for the 10B....

"The same insructions apply to these sets as to the foregoing Models 10 and 10-A, excepting that these later sets are equipped with the 3-point antenna tap switch. For most purposes this should be set at the center point. For stations below 20 on the dial, the first or nearest point should be used.The 3rd or farthest point may be useful when a very short antenna is used, or for reception of the higher wavelength stations. A change in the position of this switch requires a readjustment of the first or left hand dial."

You might want to look for a repro of the operating instructions as it gives you approximate dial settings.

Thanks, yes I was changing the tap switch, the position that worked best was the one that is used when the knob is rotated full clockwise, the center tap worked but the volume was a little lower, the other tap ( full counter clockwise) was even lower volume, but this changing of the tap switch did not make me change any of the tuning condensers
Tom

:Tom,
:
:Try changing the antenna tap switch - located to the far left of the radio and on top of the antenna coil. Here's what's in the operating instructions for the 10B....
:
:"The same insructions apply to these sets as to the foregoing Models 10 and 10-A, excepting that these later sets are equipped with the 3-point antenna tap switch. For most purposes this should be set at the center point. For stations below 20 on the dial, the first or nearest point should be used.The 3rd or farthest point may be useful when a very short antenna is used, or for reception of the higher wavelength stations. A change in the position of this switch requires a readjustment of the first or left hand dial."
:
:You might want to look for a repro of the operating instructions as it gives you approximate dial settings.

How are you tuning it? You need to adjust all 3 dials as simultaneously as possible and they should all be near - but not necessarily exactly - the same reading (Station "X" may be at 35/33/37 on the 3 dials respectively). Tweak each one carefully to get the best signal - this may take a couple of trys. Make sure your tuning condensers are in sync - sometimes the knobs become loose and they can get out of sync. If that doesn't work, then look into the tuning cap cans to make sure there are no intermittent shorts, loose connections, loose plates, etc. Also check coils for broken windings and loose connections.

JGJ, I went to an Atwater Kent website and found the manual you were talking about and printed it out. but the main thing I did was to restring my antenna this made a BIG difference. I would have to say it now works just as well as my Fada TRF radio. So now all I have to do is to build a power supply to power it so I can reinstall the one I was using back in the Fada. I saw what you said about checking for open coils, this is where this whole thing started. I could not get any signal through the 1st RF stage but I could not find anything wrong(open coils etc..) The next day I went back to it and cleaned the tips of the tubes and from that point it started working. Check the easy things!!!
Thanks for the help
Tom

:How are you tuning it? You need to adjust all 3 dials as simultaneously as possible and they should all be near - but not necessarily exactly - the same reading (Station "X" may be at 35/33/37 on the 3 dials respectively). Tweak each one carefully to get the best signal - this may take a couple of trys. Make sure your tuning condensers are in sync - sometimes the knobs become loose and they can get out of sync. If that doesn't work, then look into the tuning cap cans to make sure there are no intermittent shorts, loose connections, loose plates, etc. Also check coils for broken windings and loose connections.

Great Tom!!! You've also learned a valuable lesson that took me a couple of years to learn - be optimistic in your radio repairs. Don't assume it's a worse-case scenario - check the simple stuff first. I could still kick myself for the times I've poured over a set for days just to find it was a bad plug, intermittent switch, loose wire, etc. I once got a great radio from a (locally) well-known "pro". He gave me a good deal because it was a "weak player" and he couldn't figure out why. I looked it over at home and found a well-hidden wire to the tuning cap that was aloose. I soldered it back and the radio played like gangbusters......