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This old barn beast could damage a perfectly good reputation. Picked it up for $50.00 and if I knew then what
I know now I would have never touched it for half the price. Speaker cone was gone, output tfmr open and the
connecting wires and connector was gone. Had the cone and voice coil rebuilt and replaced output tfmer with a reasonable facsimilly (125D) the dynamic coil was good. Replaced 77-two 78's and a 42. I've checked all coils 3 times
all good except for the shadow meter and I rewound it. Replaced all caps and I've got B+ where it should be.
The oscillator seems to be running. I've checked with another little radio and i can make it scream by using the
tuning condenser on the 116b. About all I can get from it is the scratching noise from the dirty volume control.
I can't look at this thing any more, gives me heartburn. Can anyone point me in a direction where I might be able
to find this problem? Same on all bands Thanks..
Danny
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Scratching sound is good, meaning the audio is somewhat alive.
When you touch the audio driver 42 grid, does it hum? When you keep touching grids going backwards, does it stop somewhere?
Good time for alignment. See if the signal goes through.
People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
(This post was last modified: 05-05-2016, 02:43 PM by morzh.)
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42 driver yes
77 1st audio yes
78 RF no
76 OSC yes
77 1st det yes
78 1st IF no
78 2nd IF yes not very loud
37 2nd det no.
Did not mess with output 42's.
getting noises something must be working.
thanks for your help
Danny
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Try to put some signal through. You could try the IF frequency, see if it is heard.
If your coils are OK, short of oscillator misbehaving you should have it go through.
People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
Posts: 64
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(05-05-2016, 07:28 PM)morzh Wrote: Try to put some signal through. You could try the IF frequency, see if it is heard.
If your coils are OK, short of oscillator misbehaving you should have it go through.
Thanks, I'll give it a go....
Danny
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(05-06-2016, 08:34 AM)Danny Wrote: (05-05-2016, 07:28 PM)morzh Wrote: Try to put some signal through. You could try the IF frequency, see if it is heard.
If your coils are OK, short of oscillator misbehaving you should have it go through.
Thanks, I'll give it a go....
Finally got a chance to get back at this. Shot tone (460Khz) to RF grid good strong tone.
Same goes for 1st Det . Same for 1st I.F. .
It's the 2nd I.F. there is a amplitude issue. Tone yes but very weak.
At 1st Audio great tone and the same with the Dvr.
Question : The 2nd I.F. is weak but only when I connect signal directly to grid
of the 2nd I.F. The stages directly before 2nd I.F. (1st I.F.) I get a good tone.
I'd think it wouldn't because of the 2nd I.F. stage was almost silent ? I'm going
to take a look at the 2nd I.F. layout for now.
Thanks for all the assistance...
Danny
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City: Roslyn Pa
So if you apply a 460kc signal to the grid cap the 77 mixer tube do you get a good loud signal from the spkr??
If not peak IF trimmers for max audio output. If that doesn't help much check voltages around the mixer and IF amp tubes. You may have a bad resistor causing low voltage on one or more of these stages.
Terry
(This post was last modified: 05-08-2016, 06:49 PM by Radioroslyn.)
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Strong tone on the 1st det/mixer 77.
Still weak signal when on 2nd IF 78.
Danny
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Is the 77 good?
People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
Posts: 64
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NOS Tested with Heathkit IT 17.Also swaped 77 1st audio and 77 det. Same results.
Danny
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Let me understand: when you are talking of "strong tone/weak tone" you mean injecting modulated IF signal into (where?) grid cap of the respective tube and hearing it out of the speaker? Right?
And do you take the grid cap wire off? Or leave it on the cap?
Also, have you replaced the out-of-specs resistors?
And all of the tubes have been tested good?
And you did try to peak 51, 53 and 54 caps in the 1-to-2 IF xfmr (52) and 57 and 59 caps in the 58 IF xfmr?
People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
(This post was last modified: 05-09-2016, 04:53 PM by morzh.)
Posts: 64
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Joined: Oct 2006
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Let me understand: when you are talking of "strong tone/weak tone" you mean injecting modulated IF signal into (where?) grid cap of the respective tube and hearing it out of the speaker? Right? Right
And do you take the grid cap wire off? Or leave it on the cap? Mostly on. Took cap off 1st det only.
Also, have you replaced the out-of-specs resistors? Double checking out of spec resistors.
And all of the tubes have been tested good? Yes
And you did try to peak 51, 53 and 54 caps in the 1-to-2 IF xfmr (52) and 57 and 59 caps in the 58 IF xfmr?
No I have not. I will do this after checking out of spec resistors.
I've got some time today so I'm on this the rest of the afternoon. If you can think of anything else I need
to do just let me know. Thank you. I do appreciate your help
Danny
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Not a problem.
It's just from what you have describe it looks like everything works and just needs to be aligned.
This is why you probably want to make sure everything parts-wise is copacetic, we usually do that before we start troubleshooting, else you give yourself an unnecessary exercise, and then try to align, and then, if it is still fighting you, do the troubleshooting, which will then be restricted to much smaller search field.
People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
(This post was last modified: 05-10-2016, 10:36 AM by morzh.)
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When you are injecting signals keep the grid caps on. If you don't it screws with the avc because there is no ground return and allows ac modulation to be picked up by grid of the tube making thing sounds garbled.
Terry
Posts: 64
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I'm going to set this monster aside for the time being.
Thanks to all for the help. I'm going to look at this GE
A 82.. Get my mind off of this 116b for a while.
Danny
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