Check AVC voltage in your radio. It should go negative on stronger stations cutting back on gain. A radio may operate with zero AVC voltage but strong stations will be too loud and distorted.
Resistance of your volume control is not a problem. It's just a divider between signal and ground.
http://www.nostalgiaair.org/PagesByModel/209/M0025209.pdf
Norm
:I'm currently working on a Zenith 6S229. I have replaced ALL capacitors and resistors in this set and it is a strong performer on all bands. However, I have one small annoying problem that keeps me from enjoying this set. The volume control is EXTREMELY sensitive, a one quarter turn on the volume control makes the radio too loud. I removed the volume control to make sure it was not a linear taper, it is indeed an audio taper unit. The schematic calls for a 400K pot and this is a 500K unit, but I wouldn't think that is the problem. Probably more annoying than the sensitive volume control, is the fact that the volume control will not kill the sound when turned all the way down. On a strong station the radio is almost "listenable" with the volume in the full CCW position against the on/off detent. Can anyone lead me in the right direction? Where do I start looking? This set uses a Centralab N-103 pot with switch. Help Me! David
If I check the AVC voltage and it is not working, can you give me a hint as tho what components are in the AVC circuit? I have replaced everything in this radio and double checked each component value. Everything seems OK, but I will check again. Thanks for the suggestions and Merry Christmas!
David
:Hi David
:
: Check AVC voltage in your radio. It should go negative on stronger stations cutting back on gain. A radio may operate with zero AVC voltage but strong stations will be too loud and distorted.
:
: Resistance of your volume control is not a problem. It's just a divider between signal and ground.
:
:http://www.nostalgiaair.org/PagesByModel/209/M0025209.pdf
:
:Norm
:
::I'm currently working on a Zenith 6S229. I have replaced ALL capacitors and resistors in this set and it is a strong performer on all bands. However, I have one small annoying problem that keeps me from enjoying this set. The volume control is EXTREMELY sensitive, a one quarter turn on the volume control makes the radio too loud. I removed the volume control to make sure it was not a linear taper, it is indeed an audio taper unit. The schematic calls for a 400K pot and this is a 500K unit, but I wouldn't think that is the problem. Probably more annoying than the sensitive volume control, is the fact that the volume control will not kill the sound when turned all the way down. On a strong station the radio is almost "listenable" with the volume in the full CCW position against the on/off detent. Can anyone lead me in the right direction? Where do I start looking? This set uses a Centralab N-103 pot with switch. Help Me! David
See to it that C8 is functioning properly.
If you find no trouble in any of these components, disconnect your volume control and check its operation with your multi-meter. Towards the very end of the scale use your X100 or X1 scale. Check to see that resistance doesn't jump around here. For the majority of the scale, X10,000 should be used, but for the ends, the smaller, less sensitive scales should be used.
If you find trouble, disassemble the control. Remove the C clip from the shaft and remove the shaft-rotor assembly. Wash the carbon element in dish soap and water. Dry it well and inspect it for cracks and excessive wear. If excessive wear is obvious, relocate the wipers on the rotor so that they contact a fresher area on the carbon. Go to your automotive parts jobber and purchase a tube of di-electric grease. Wipe a very thin film of this grease onto the carbon. Wipe some onto the shaft of the rotor as well. Reassemble the control and check its operation both with a meter and then with the radio.
If you still cannot obtain satisfactory performance, you can try inserting a 100 to 500K resistor between the control and the IF transformer. The AVC line should then be moved to the IF transformer side of the resistor. It should not be left on the volume control side. Different resistor values will create different tonal effects, so select a resistor that lends the most pleasing effect. If this still does not solve the problem, switched units are readily available from www.tubesandmore.com, and they may still be available from Radio Shack. I know that Radio Shack sells the potentiometers. I do not know if they sell the switching units, which snap onto the backs, anymore. I do not recommend that you replace the original unit unless you cannot get it to perform properly. You may even have trouble with the shaft of the new control, if your shaft is not available, though there usually is a way to modify the shaft--file it half round, or cut a slot in the middle for those slotted type shafts, and then file slightly smaller in diameter.
Thomas
I checked voltages on the tubes and I found a problem. The grid of the 6F6 should be -3.5 volts but I have a reading of -21.7 volts. No that is not a typo, -21.7 volts! I'm working from a schematic printed from this site, but I cannot read some of the values. There are two resistors between the negative side of electrolytic C16 and the grid of the 6F6. It looks like R6 (220K) and R7 (470K) also there are two little notes indicated next to the intersection of R6, R7 and C8. Next to C8 there is a circled 'A' but I can't find the related information for 'A'. Also, next to what I believe is R6, it looks to be a circled 'B', but I can't find any information on 'B' either. Do I have the wrong resistors in place because of my bad schematic? Something is causing that -21 volts, I just need to know what it could be. David R
:C2, over by the band switch, is your AVC filtering condenser (non-electrolytic, .05 MFD). This condenser must be in TOP NOTCH CONDITION. Absolutely no leakage! R4 must also have not drifted.
:
:See to it that C8 is functioning properly.
:
:If you find no trouble in any of these components, disconnect your volume control and check its operation with your multi-meter. Towards the very end of the scale use your X100 or X1 scale. Check to see that resistance doesn't jump around here. For the majority of the scale, X10,000 should be used, but for the ends, the smaller, less sensitive scales should be used.
:
:If you find trouble, disassemble the control. Remove the C clip from the shaft and remove the shaft-rotor assembly. Wash the carbon element in dish soap and water. Dry it well and inspect it for cracks and excessive wear. If excessive wear is obvious, relocate the wipers on the rotor so that they contact a fresher area on the carbon. Go to your automotive parts jobber and purchase a tube of di-electric grease. Wipe a very thin film of this grease onto the carbon. Wipe some onto the shaft of the rotor as well. Reassemble the control and check its operation both with a meter and then with the radio.
:
:If you still cannot obtain satisfactory performance, you can try inserting a 100 to 500K resistor between the control and the IF transformer. The AVC line should then be moved to the IF transformer side of the resistor. It should not be left on the volume control side. Different resistor values will create different tonal effects, so select a resistor that lends the most pleasing effect. If this still does not solve the problem, switched units are readily available from www.tubesandmore.com, and they may still be available from Radio Shack. I know that Radio Shack sells the potentiometers. I do not know if they sell the switching units, which snap onto the backs, anymore. I do not recommend that you replace the original unit unless you cannot get it to perform properly. You may even have trouble with the shaft of the new control, if your shaft is not available, though there usually is a way to modify the shaft--file it half round, or cut a slot in the middle for those slotted type shafts, and then file slightly smaller in diameter.
:
:Thomas
I forgot to address your answers in my follow-up. All capacitors are new, including C2 and C8. I checked them again with my meter, they are indeed good. Also, R4 is new and tests OK with a reading of 1Mohm. The volume control is not the problem, I tested it with my meter, it works OK going down to about 50 ohms against the stop and gradually coming back up to 510K. Just for grins I substituted another pot and I got the same results as I have right now with the original pot. I also agree that replacing original pots, unless they are just really trashed, is a last resort!
:Thomas,
:
:I checked voltages on the tubes and I found a problem. The grid of the 6F6 should be -3.5 volts but I have a reading of -21.7 volts. No that is not a typo, -21.7 volts! I'm working from a schematic printed from this site, but I cannot read some of the values. There are two resistors between the negative side of electrolytic C16 and the grid of the 6F6. It looks like R6 (220K) and R7 (470K) also there are two little notes indicated next to the intersection of R6, R7 and C8. Next to C8 there is a circled 'A' but I can't find the related information for 'A'. Also, next to what I believe is R6, it looks to be a circled 'B', but I can't find any information on 'B' either. Do I have the wrong resistors in place because of my bad schematic? Something is causing that -21 volts, I just need to know what it could be. David R
:
::C2, over by the band switch, is your AVC filtering condenser (non-electrolytic, .05 MFD). This condenser must be in TOP NOTCH CONDITION. Absolutely no leakage! R4 must also have not drifted.
::
::See to it that C8 is functioning properly.
::
::If you find no trouble in any of these components, disconnect your volume control and check its operation with your multi-meter. Towards the very end of the scale use your X100 or X1 scale. Check to see that resistance doesn't jump around here. For the majority of the scale, X10,000 should be used, but for the ends, the smaller, less sensitive scales should be used.
::
::If you find trouble, disassemble the control. Remove the C clip from the shaft and remove the shaft-rotor assembly. Wash the carbon element in dish soap and water. Dry it well and inspect it for cracks and excessive wear. If excessive wear is obvious, relocate the wipers on the rotor so that they contact a fresher area on the carbon. Go to your automotive parts jobber and purchase a tube of di-electric grease. Wipe a very thin film of this grease onto the carbon. Wipe some onto the shaft of the rotor as well. Reassemble the control and check its operation both with a meter and then with the radio.
::
::If you still cannot obtain satisfactory performance, you can try inserting a 100 to 500K resistor between the control and the IF transformer. The AVC line should then be moved to the IF transformer side of the resistor. It should not be left on the volume control side. Different resistor values will create different tonal effects, so select a resistor that lends the most pleasing effect. If this still does not solve the problem, switched units are readily available from www.tubesandmore.com, and they may still be available from Radio Shack. I know that Radio Shack sells the potentiometers. I do not know if they sell the switching units, which snap onto the backs, anymore. I do not recommend that you replace the original unit unless you cannot get it to perform properly. You may even have trouble with the shaft of the new control, if your shaft is not available, though there usually is a way to modify the shaft--file it half round, or cut a slot in the middle for those slotted type shafts, and then file slightly smaller in diameter.
::
::Thomas
Minus 21 volts is ok on your 6F6 grid for bias. Older meters, 1000 ohms/volt, would load down voltage supplied through large value resistors. The data books shows a 6F6 should have -20 volts on grid 1 with 285 on the plate.
Connect one meter lead to the AVC line and the other to B- in your radio. As you tune to stronger stations AVC should read - 10 volts or more.
Norm
:Thomas,
:
:I forgot to address your answers in my follow-up. All capacitors are new, including C2 and C8. I checked them again with my meter, they are indeed good. Also, R4 is new and tests OK with a reading of 1Mohm. The volume control is not the problem, I tested it with my meter, it works OK going down to about 50 ohms against the stop and gradually coming back up to 510K. Just for grins I substituted another pot and I got the same results as I have right now with the original pot. I also agree that replacing original pots, unless they are just really trashed, is a last resort!
:
::Thomas,
::
::I checked voltages on the tubes and I found a problem. The grid of the 6F6 should be -3.5 volts but I have a reading of -21.7 volts. No that is not a typo, -21.7 volts! I'm working from a schematic printed from this site, but I cannot read some of the values. There are two resistors between the negative side of electrolytic C16 and the grid of the 6F6. It looks like R6 (220K) and R7 (470K) also there are two little notes indicated next to the intersection of R6, R7 and C8. Next to C8 there is a circled 'A' but I can't find the related information for 'A'. Also, next to what I believe is R6, it looks to be a circled 'B', but I can't find any information on 'B' either. Do I have the wrong resistors in place because of my bad schematic? Something is causing that -21 volts, I just need to know what it could be. David R
::
:::C2, over by the band switch, is your AVC filtering condenser (non-electrolytic, .05 MFD). This condenser must be in TOP NOTCH CONDITION. Absolutely no leakage! R4 must also have not drifted.
:::
:::See to it that C8 is functioning properly.
:::
:::If you find no trouble in any of these components, disconnect your volume control and check its operation with your multi-meter. Towards the very end of the scale use your X100 or X1 scale. Check to see that resistance doesn't jump around here. For the majority of the scale, X10,000 should be used, but for the ends, the smaller, less sensitive scales should be used.
:::
:::If you find trouble, disassemble the control. Remove the C clip from the shaft and remove the shaft-rotor assembly. Wash the carbon element in dish soap and water. Dry it well and inspect it for cracks and excessive wear. If excessive wear is obvious, relocate the wipers on the rotor so that they contact a fresher area on the carbon. Go to your automotive parts jobber and purchase a tube of di-electric grease. Wipe a very thin film of this grease onto the carbon. Wipe some onto the shaft of the rotor as well. Reassemble the control and check its operation both with a meter and then with the radio.
:::
:::If you still cannot obtain satisfactory performance, you can try inserting a 100 to 500K resistor between the control and the IF transformer. The AVC line should then be moved to the IF transformer side of the resistor. It should not be left on the volume control side. Different resistor values will create different tonal effects, so select a resistor that lends the most pleasing effect. If this still does not solve the problem, switched units are readily available from www.tubesandmore.com, and they may still be available from Radio Shack. I know that Radio Shack sells the potentiometers. I do not know if they sell the switching units, which snap onto the backs, anymore. I do not recommend that you replace the original unit unless you cannot get it to perform properly. You may even have trouble with the shaft of the new control, if your shaft is not available, though there usually is a way to modify the shaft--file it half round, or cut a slot in the middle for those slotted type shafts, and then file slightly smaller in diameter.
:::
:::Thomas
I checked the voltage of the AVC as you suggested and found when off station the voltage is 20 VDC when tuned to a strong station the voltage drops to 7.5 VDC but never even approaches a negative voltage. Now that I know the problem, the big question is what causes the voltage to be too high? Are there specific components I should look at? Every resistor and cap are new, I don't know where to start.
:Hi David
:
: Minus 21 volts is ok on your 6F6 grid for bias. Older meters, 1000 ohms/volt, would load down voltage supplied through large value resistors. The data books shows a 6F6 should have -20 volts on grid 1 with 285 on the plate.
:
: Connect one meter lead to the AVC line and the other to B- in your radio. As you tune to stronger stations AVC should read - 10 volts or more.
:
:Norm
:
::Thomas,
::
::I forgot to address your answers in my follow-up. All capacitors are new, including C2 and C8. I checked them again with my meter, they are indeed good. Also, R4 is new and tests OK with a reading of 1Mohm. The volume control is not the problem, I tested it with my meter, it works OK going down to about 50 ohms against the stop and gradually coming back up to 510K. Just for grins I substituted another pot and I got the same results as I have right now with the original pot. I also agree that replacing original pots, unless they are just really trashed, is a last resort!
::
:::Thomas,
:::
:::I checked voltages on the tubes and I found a problem. The grid of the 6F6 should be -3.5 volts but I have a reading of -21.7 volts. No that is not a typo, -21.7 volts! I'm working from a schematic printed from this site, but I cannot read some of the values. There are two resistors between the negative side of electrolytic C16 and the grid of the 6F6. It looks like R6 (220K) and R7 (470K) also there are two little notes indicated next to the intersection of R6, R7 and C8. Next to C8 there is a circled 'A' but I can't find the related information for 'A'. Also, next to what I believe is R6, it looks to be a circled 'B', but I can't find any information on 'B' either. Do I have the wrong resistors in place because of my bad schematic? Something is causing that -21 volts, I just need to know what it could be. David R
:::
::::C2, over by the band switch, is your AVC filtering condenser (non-electrolytic, .05 MFD). This condenser must be in TOP NOTCH CONDITION. Absolutely no leakage! R4 must also have not drifted.
::::
::::See to it that C8 is functioning properly.
::::
::::If you find no trouble in any of these components, disconnect your volume control and check its operation with your multi-meter. Towards the very end of the scale use your X100 or X1 scale. Check to see that resistance doesn't jump around here. For the majority of the scale, X10,000 should be used, but for the ends, the smaller, less sensitive scales should be used.
::::
::::If you find trouble, disassemble the control. Remove the C clip from the shaft and remove the shaft-rotor assembly. Wash the carbon element in dish soap and water. Dry it well and inspect it for cracks and excessive wear. If excessive wear is obvious, relocate the wipers on the rotor so that they contact a fresher area on the carbon. Go to your automotive parts jobber and purchase a tube of di-electric grease. Wipe a very thin film of this grease onto the carbon. Wipe some onto the shaft of the rotor as well. Reassemble the control and check its operation both with a meter and then with the radio.
::::
::::If you still cannot obtain satisfactory performance, you can try inserting a 100 to 500K resistor between the control and the IF transformer. The AVC line should then be moved to the IF transformer side of the resistor. It should not be left on the volume control side. Different resistor values will create different tonal effects, so select a resistor that lends the most pleasing effect. If this still does not solve the problem, switched units are readily available from www.tubesandmore.com, and they may still be available from Radio Shack. I know that Radio Shack sells the potentiometers. I do not know if they sell the switching units, which snap onto the backs, anymore. I do not recommend that you replace the original unit unless you cannot get it to perform properly. You may even have trouble with the shaft of the new control, if your shaft is not available, though there usually is a way to modify the shaft--file it half round, or cut a slot in the middle for those slotted type shafts, and then file slightly smaller in diameter.
::::
::::Thomas
When I find positive AVC it's usually a gassy IF or RF tube. Do you see purple glow inside?
A gassy tube ionizes inside. Grid being between cathode and plate will be positive. This will feedback through an IF transformer to the AVC line.
Norm
:Norm,
:
:I checked the voltage of the AVC as you suggested and found when off station the voltage is 20 VDC when tuned to a strong station the voltage drops to 7.5 VDC but never even approaches a negative voltage. Now that I know the problem, the big question is what causes the voltage to be too high? Are there specific components I should look at? Every resistor and cap are new, I don't know where to start.
:
::Hi David
::
:: Minus 21 volts is ok on your 6F6 grid for bias. Older meters, 1000 ohms/volt, would load down voltage supplied through large value resistors. The data books shows a 6F6 should have -20 volts on grid 1 with 285 on the plate.
::
:: Connect one meter lead to the AVC line and the other to B- in your radio. As you tune to stronger stations AVC should read - 10 volts or more.
::
::Norm
::
:::Thomas,
:::
:::I forgot to address your answers in my follow-up. All capacitors are new, including C2 and C8. I checked them again with my meter, they are indeed good. Also, R4 is new and tests OK with a reading of 1Mohm. The volume control is not the problem, I tested it with my meter, it works OK going down to about 50 ohms against the stop and gradually coming back up to 510K. Just for grins I substituted another pot and I got the same results as I have right now with the original pot. I also agree that replacing original pots, unless they are just really trashed, is a last resort!
:::
::::Thomas,
::::
::::I checked voltages on the tubes and I found a problem. The grid of the 6F6 should be -3.5 volts but I have a reading of -21.7 volts. No that is not a typo, -21.7 volts! I'm working from a schematic printed from this site, but I cannot read some of the values. There are two resistors between the negative side of electrolytic C16 and the grid of the 6F6. It looks like R6 (220K) and R7 (470K) also there are two little notes indicated next to the intersection of R6, R7 and C8. Next to C8 there is a circled 'A' but I can't find the related information for 'A'. Also, next to what I believe is R6, it looks to be a circled 'B', but I can't find any information on 'B' either. Do I have the wrong resistors in place because of my bad schematic? Something is causing that -21 volts, I just need to know what it could be. David R
::::
:::::C2, over by the band switch, is your AVC filtering condenser (non-electrolytic, .05 MFD). This condenser must be in TOP NOTCH CONDITION. Absolutely no leakage! R4 must also have not drifted.
:::::
:::::See to it that C8 is functioning properly.
:::::
:::::If you find no trouble in any of these components, disconnect your volume control and check its operation with your multi-meter. Towards the very end of the scale use your X100 or X1 scale. Check to see that resistance doesn't jump around here. For the majority of the scale, X10,000 should be used, but for the ends, the smaller, less sensitive scales should be used.
:::::
:::::If you find trouble, disassemble the control. Remove the C clip from the shaft and remove the shaft-rotor assembly. Wash the carbon element in dish soap and water. Dry it well and inspect it for cracks and excessive wear. If excessive wear is obvious, relocate the wipers on the rotor so that they contact a fresher area on the carbon. Go to your automotive parts jobber and purchase a tube of di-electric grease. Wipe a very thin film of this grease onto the carbon. Wipe some onto the shaft of the rotor as well. Reassemble the control and check its operation both with a meter and then with the radio.
:::::
:::::If you still cannot obtain satisfactory performance, you can try inserting a 100 to 500K resistor between the control and the IF transformer. The AVC line should then be moved to the IF transformer side of the resistor. It should not be left on the volume control side. Different resistor values will create different tonal effects, so select a resistor that lends the most pleasing effect. If this still does not solve the problem, switched units are readily available from www.tubesandmore.com, and they may still be available from Radio Shack. I know that Radio Shack sells the potentiometers. I do not know if they sell the switching units, which snap onto the backs, anymore. I do not recommend that you replace the original unit unless you cannot get it to perform properly. You may even have trouble with the shaft of the new control, if your shaft is not available, though there usually is a way to modify the shaft--file it half round, or cut a slot in the middle for those slotted type shafts, and then file slightly smaller in diameter.
:::::
:::::Thomas
I'll pull the tubes and check them again. My old Jackson Tube Tester may not show gassy tubes since unlike a Hickok, it lacks a gas test. Thanks for the pointers, Merry Christmas...... David R
:Hi Dave
:
: When I find positive AVC it's usually a gassy IF or RF tube. Do you see purple glow inside?
:
: A gassy tube ionizes inside. Grid being between cathode and plate will be positive. This will feedback through an IF transformer to the AVC line.
:
:Norm
:
::Norm,
::
::I checked the voltage of the AVC as you suggested and found when off station the voltage is 20 VDC when tuned to a strong station the voltage drops to 7.5 VDC but never even approaches a negative voltage. Now that I know the problem, the big question is what causes the voltage to be too high? Are there specific components I should look at? Every resistor and cap are new, I don't know where to start.
::
:::Hi David
:::
::: Minus 21 volts is ok on your 6F6 grid for bias. Older meters, 1000 ohms/volt, would load down voltage supplied through large value resistors. The data books shows a 6F6 should have -20 volts on grid 1 with 285 on the plate.
:::
::: Connect one meter lead to the AVC line and the other to B- in your radio. As you tune to stronger stations AVC should read - 10 volts or more.
:::
:::Norm
:::
::::Thomas,
::::
::::I forgot to address your answers in my follow-up. All capacitors are new, including C2 and C8. I checked them again with my meter, they are indeed good. Also, R4 is new and tests OK with a reading of 1Mohm. The volume control is not the problem, I tested it with my meter, it works OK going down to about 50 ohms against the stop and gradually coming back up to 510K. Just for grins I substituted another pot and I got the same results as I have right now with the original pot. I also agree that replacing original pots, unless they are just really trashed, is a last resort!
::::
:::::Thomas,
:::::
:::::I checked voltages on the tubes and I found a problem. The grid of the 6F6 should be -3.5 volts but I have a reading of -21.7 volts. No that is not a typo, -21.7 volts! I'm working from a schematic printed from this site, but I cannot read some of the values. There are two resistors between the negative side of electrolytic C16 and the grid of the 6F6. It looks like R6 (220K) and R7 (470K) also there are two little notes indicated next to the intersection of R6, R7 and C8. Next to C8 there is a circled 'A' but I can't find the related information for 'A'. Also, next to what I believe is R6, it looks to be a circled 'B', but I can't find any information on 'B' either. Do I have the wrong resistors in place because of my bad schematic? Something is causing that -21 volts, I just need to know what it could be. David R
:::::
::::::C2, over by the band switch, is your AVC filtering condenser (non-electrolytic, .05 MFD). This condenser must be in TOP NOTCH CONDITION. Absolutely no leakage! R4 must also have not drifted.
::::::
::::::See to it that C8 is functioning properly.
::::::
::::::If you find no trouble in any of these components, disconnect your volume control and check its operation with your multi-meter. Towards the very end of the scale use your X100 or X1 scale. Check to see that resistance doesn't jump around here. For the majority of the scale, X10,000 should be used, but for the ends, the smaller, less sensitive scales should be used.
::::::
::::::If you find trouble, disassemble the control. Remove the C clip from the shaft and remove the shaft-rotor assembly. Wash the carbon element in dish soap and water. Dry it well and inspect it for cracks and excessive wear. If excessive wear is obvious, relocate the wipers on the rotor so that they contact a fresher area on the carbon. Go to your automotive parts jobber and purchase a tube of di-electric grease. Wipe a very thin film of this grease onto the carbon. Wipe some onto the shaft of the rotor as well. Reassemble the control and check its operation both with a meter and then with the radio.
::::::
::::::If you still cannot obtain satisfactory performance, you can try inserting a 100 to 500K resistor between the control and the IF transformer. The AVC line should then be moved to the IF transformer side of the resistor. It should not be left on the volume control side. Different resistor values will create different tonal effects, so select a resistor that lends the most pleasing effect. If this still does not solve the problem, switched units are readily available from www.tubesandmore.com, and they may still be available from Radio Shack. I know that Radio Shack sells the potentiometers. I do not know if they sell the switching units, which snap onto the backs, anymore. I do not recommend that you replace the original unit unless you cannot get it to perform properly. You may even have trouble with the shaft of the new control, if your shaft is not available, though there usually is a way to modify the shaft--file it half round, or cut a slot in the middle for those slotted type shafts, and then file slightly smaller in diameter.
::::::
::::::Thomas
Check for leakage between the primary and secondary of each IF transformer.
Your RF tubes will glow purple if gassy. The only one to be concerned with is the 6H6 tube, as this tube does not normally pass enough current to make it glow. If I knew your tester, I could tell you how to set it for more current so that you may perhaps see a purple glow.
Thomas
Regarding high quality mechanical (anolog, as they are commonly refered to) meters, any good but inexpensive Radio Shack mechanical meter will do almost as well as an expensive Simpson 260. You may purchase a Radio Shack meter with confidence.
Thomas
Richard