I looked back and saw that you have hum when touching the cap of the 6Q7 and 6K7. This is expected on the 6Q7 but the 6K7 has an IF transformer to a signal ground so it should not cause hum unless the cap is removed or transformer open. (If the hum is there with the cap removed and goes away when it's back on that's ok) Check the resisance of the IF transformer windings. These windings will be low, around 20 ohms if good.
What are the voltages on pins #3 and #4 of the 6K7? voltages on the 6A8, pins #3 and #6? Pins #3 on both tubes should be positive. The others will also be positive but at a lower level.
You are right to work on the broadcast band first. It's much easier than finding stations on short wave.
Norm
: norm,
: i do have the hum when i touch the grid cap. when i said noise, i meant static. the filter caps seem to be fine. eddie
Looking back again, I see the oscillator isn't operating. Measureing the B+ voltages on the pins listed in the earlier message may give us a reason. You could also check resistance of the oscillator coils. Be sure the band switch contacts are clean.
Norm
: norm,
: i do have the hum when i touch the grid cap. when i said noise, i meant static. the filter caps seem to be fine. eddie
: Looking back again, I see the oscillator isn't operating. Measureing the B+ voltages on the pins listed in the earlier message may give us a reason. You could also check resistance of the oscillator coils. Be sure the band switch contacts are clean.
: Norm
: : norm,
: : i do have the hum when i touch the grid cap. when i said noise, i meant static. the filter caps seem to be fine. eddie
norm,
here are the voltages:
6k7
3=96v dc, .5 ac
4=93v dc, .6 ac
6a8
3=98v dc, 1.1v ac
6=86v dc, 1.6v ac
i got 12 ohms on one sideof the transformer, up in the meg ohms on the other
i do have the hum with the grid attached to the 6k7 tube.
almost open if transformer?
eddie
Looks like the secondary of the IF transformer is open. The resistance is far too high and you shouldn't hear hum touching the cap of the 6K7.
There are several ways you can repair the radio. You may be able to remove the cover and resolder a bad connection at a terminal. The IF transformer can be replaced or you can use R/C coupling.
For R/C coupling solder a 100K resistor across the open winding and connect a small capacitor, 100 pf, from the plate of the 6A8 to the grid of the 6K7. The exact values are not critical.
The radio will work with R/C coupling but you should peak up the IF transformer for max volume.
Norm
: : Eddie
: : Looking back again, I see the oscillator isn't operating. Measureing the B+ voltages on the pins listed in the earlier message may give us a reason. You could also check resistance of the oscillator coils. Be sure the band switch contacts are clean.
: : Norm
:
: : : norm,
: : : i do have the hum when i touch the grid cap. when i said noise, i meant static. the filter caps seem to be fine. eddie
: norm,
: here are the voltages:
: 6k7
: 3=96v dc, .5 ac
: 4=93v dc, .6 ac
: 6a8
: 3=98v dc, 1.1v ac
: 6=86v dc, 1.6v ac
: i got 12 ohms on one sideof the transformer, up in the meg ohms on the other
: i do have the hum with the grid attached to the 6k7 tube.
: almost open if transformer?
: eddie
Eddie
: Looks like the secondary of the IF transformer is open. The resistance is far too high and you shouldn't hear hum touching the cap of the 6K7.
: There are several ways you can repair the radio. You may be able to remove the cover and resolder a bad connection at a terminal. The IF transformer can be replaced or you can use R/C coupling.
: For R/C coupling solder a 100K resistor across the open winding and connect a small capacitor, 100 pf, from the plate of the 6A8 to the grid of the 6K7. The exact values are not critical.
: The radio will work with R/C coupling but you should peak up the IF transformer for max volume.
: Norm
:
: : : Eddie
: : : Looking back again, I see the oscillator isn't operating. Measureing the B+ voltages on the pins listed in the earlier message may give us a reason. You could also check resistance of the oscillator coils. Be sure the band switch contacts are clean.
: : : Norm
: :
: : : : norm,
: : : : i do have the hum when i touch the grid cap. when i said noise, i meant static. the filter caps seem to be fine. eddie
: : norm,
: : here are the voltages:
: : 6k7
: : 3=96v dc, .5 ac
: : 4=93v dc, .6 ac
: : 6a8
: : 3=98v dc, 1.1v ac
: : 6=86v dc, 1.6v ac
: : i got 12 ohms on one sideof the transformer, up in the meg ohms on the other
: : i do have the hum with the grid attached to the 6k7 tube.
: : almost open if transformer?
: : eddie
Norm
: norm, on the 100pf cap. will a .001mf work. i get confused on these cap values. i will try the r/c coupling tonight.....thanks...eddie
: Eddie
: : Looks like the secondary of the IF transformer is open. The resistance is far too high and you shouldn't hear hum touching the cap of the 6K7.
: : There are several ways you can repair the radio. You may be able to remove the cover and resolder a bad connection at a terminal. The IF transformer can be replaced or you can use R/C coupling.
: : For R/C coupling solder a 100K resistor across the open winding and connect a small capacitor, 100 pf, from the plate of the 6A8 to the grid of the 6K7. The exact values are not critical.
: : The radio will work with R/C coupling but you should peak up the IF transformer for max volume.
: : Norm
: :
: : : : Eddie
: : : : Looking back again, I see the oscillator isn't operating. Measureing the B+ voltages on the pins listed in the earlier message may give us a reason. You could also check resistance of the oscillator coils. Be sure the band switch contacts are clean.
: : : : Norm
: : :
: : : : : norm,
: : : : : i do have the hum when i touch the grid cap. when i said noise, i meant static. the filter caps seem to be fine. eddie
: : : norm,
: : : here are the voltages:
: : : 6k7
: : : 3=96v dc, .5 ac
: : : 4=93v dc, .6 ac
: : : 6a8
: : : 3=98v dc, 1.1v ac
: : : 6=86v dc, 1.6v ac
: : : i got 12 ohms on one sideof the transformer, up in the meg ohms on the other
: : : i do have the hum with the grid attached to the 6k7 tube.
: : : almost open if transformer?
: : : eddie
would that be from pin 3 on the 6a8 to pin 4 on the 6k7?
Eddie, it would be better if you had a smaller value. A .001 mf is 1000 pf and this large of value will not allow as sharp tuning of the IF transformer. If you don't have anything smaller, it will work.
: Norm
: : norm, on the 100pf cap. will a .001mf work. i get confused on these cap values. i will try the r/c coupling tonight.....thanks...eddie
:
: : Eddie
:
: : : Looks like the secondary of the IF transformer is open. The resistance is far too high and you shouldn't hear hum touching the cap of the 6K7.
:
: : : There are several ways you can repair the radio. You may be able to remove the cover and resolder a bad connection at a terminal. The IF transformer can be replaced or you can use R/C coupling.
:
: : : For R/C coupling solder a 100K resistor across the open winding and connect a small capacitor, 100 pf, from the plate of the 6A8 to the grid of the 6K7. The exact values are not critical.
:
: : : The radio will work with R/C coupling but you should peak up the IF transformer for max volume.
:
: : : Norm
:
: : :
: : : : : Eddie
:
: : : : : Looking back again, I see the oscillator isn't operating. Measureing the B+ voltages on the pins listed in the earlier message may give us a reason. You could also check resistance of the oscillator coils. Be sure the band switch contacts are clean.
:
: : : : : Norm
:
: : : :
: : : : : : norm,
: : : : : : i do have the hum when i touch the grid cap. when i said noise, i meant static. the filter caps seem to be fine. eddie
:
: : : : norm,
: : : : here are the voltages:
:
: : : : 6k7
: : : : 3=96v dc, .5 ac
: : : : 4=93v dc, .6 ac
:
: : : : 6a8
: : : : 3=98v dc, 1.1v ac
: : : : 6=86v dc, 1.6v ac
:
: : : : i got 12 ohms on one sideof the transformer, up in the meg ohms on the other
:
: : : : i do have the hum with the grid attached to the 6k7 tube.
:
: : : : almost open if transformer?
:
: : : : eddie
i repaired the if transformer, wasn't really bad. the grid cap had a poor connection. i get no hum when i touch the grid cap on the 6k7 now. all it does is kill the small amount of audio i'm getting. i now have 12 or 13 ohms thru each coil. eddie
:norm,
: would that be from pin 3 on the 6a8 to pin 4 on the 6k7?
: Eddie, it would be better if you had a smaller value. A .001 mf is 1000 pf and this large of value will not allow as sharp tuning of the IF transformer. If you don't have anything smaller, it will work.
: : Norm
: : : norm, on the 100pf cap. will a .001mf work. i get confused on these cap values. i will try the r/c coupling tonight.....thanks...eddie
: :
: : : Eddie
: :
: : : : Looks like the secondary of the IF transformer is open. The resistance is far too high and you shouldn't hear hum touching the cap of the 6K7.
: :
: : : : There are several ways you can repair the radio. You may be able to remove the cover and resolder a bad connection at a terminal. The IF transformer can be replaced or you can use R/C coupling.
: :
: : : : For R/C coupling solder a 100K resistor across the open winding and connect a small capacitor, 100 pf, from the plate of the 6A8 to the grid of the 6K7. The exact values are not critical.
: :
: : : : The radio will work with R/C coupling but you should peak up the IF transformer for max volume.
: :
: : : : Norm
: :
: : : :
: : : : : : Eddie
: :
: : : : : : Looking back again, I see the oscillator isn't operating. Measureing the B+ voltages on the pins listed in the earlier message may give us a reason. You could also check resistance of the oscillator coils. Be sure the band switch contacts are clean.
: :
: : : : : : Norm
: :
: : : : :
: : : : : : : norm,
: : : : : : : i do have the hum when i touch the grid cap. when i said noise, i meant static. the filter caps seem to be fine. eddie
: :
: : : : : norm,
: : : : : here are the voltages:
: :
: : : : : 6k7
: : : : : 3=96v dc, .5 ac
: : : : : 4=93v dc, .6 ac
: :
: : : : : 6a8
: : : : : 3=98v dc, 1.1v ac
: : : : : 6=86v dc, 1.6v ac
: :
: : : : : i got 12 ohms on one sideof the transformer, up in the meg ohms on the other
: :
: : : : : i do have the hum with the grid attached to the 6k7 tube.
: :
: : : : : almost open if transformer?
: :
: : : : : eddie