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-   -   sound buzz (http://www.videokarma.org/showthread.php?t=259882)

radio nut 11-30-2013 02:40 PM

I did go ahead and put in mica caps where mica once were at. If I understand Wa2ise's explanation seems like another run at calibration is in order. I can do that!

dieseljeep 11-30-2013 03:12 PM

Quote:

Originally Posted by radio nut (Post 3085913)
this muntz does not have fine tuning.....high end huh?

One of Muntz's selling points was the fact, that once the set was set up in your home, it didn't need any adjustment, either by technician or user.
We all know how that worked out. They even had a set screw on the channel selector knob. :scratch2:

wa2ise 11-30-2013 04:12 PM

Quote:

Originally Posted by dieseljeep (Post 3088503)
One of Muntz's selling points was the fact, that once the set was set up in your home, it didn't need any adjustment, either by technician or user.

That's probably because the set's video IF had a passband as wide as a barn door. So the local oscillator in the tuner drifting wouldn't matter. Taking full advantage of the FCC not placing TV stations in adjacent channels. It should look awful on analog cable.

radio nut 11-30-2013 06:44 PM

with a dvd player and not giving me problems this set has as good a picture as I have seen on a black and white set and good (very loud if pushed) audio.
Just wish it was not problem after problem. This has been the biggest lemon as far as problems.....

I had a cbs- Colombia set once that took 8 hours on one weekend to get running and that was it. no problems after that except a tube here and there..and it was not calibrated ....just horizontal set up with a scope to minimize fly temp.

radio nut 12-01-2013 11:52 AM

I realized that I had the secondary of the ratio detector coil wired wrong. I redid it and for about 30 minutes the sound was clean ......and then the buzz slowly came back! that was after I had ran the set for about one hour.

radio nut 12-01-2013 12:53 PM

well, I guess I should state that when the sound was clean there was a slight buzz that I felt was tolerable, barely there.....
just got curious and......there is resistance on my ohmmeter from either "leg" of the primary to the secondary of the audio output transformer.
that means that is where the buzz is coming from....a shorted transformer!

old_coot88 12-01-2013 04:01 PM

Quote:

Originally Posted by radio nut (Post 3088594)
...there is resistance on my ohmmeter from either "leg" of the primary to the secondary of the audio output transformer.
that means that is where the buzz is coming from....a shorted transformer!

Not necessarily. Did you completely isolate (ie., disconnect both leads of either the primary or secondary) before taking the measurement?

radio nut 12-01-2013 04:14 PM

since the output hooks to nothing but a speaker and that was not connected I did not unsolder the primary side

radio nut 12-01-2013 04:18 PM

shoot!...... I just checked the diagram and one side of the secondary does go to ground........Ok, I will unsolder wires then.
right after shutting the set off it read earlier about 6400 ohms from primary to secondary.
after sitting it still shows about 8 meg so I had guessed that the tranny was shorted and heating making it worse.

old_coot88 12-01-2013 06:37 PM

Quote:

Originally Posted by radio nut (Post 3088612)
shoot!...... I just checked the diagram and one side of the secondary does go to ground........Ok, I will unsolder wires then.
right after shutting the set off it read earlier about 6400 ohms from primary to secondary.
after sitting it still shows about 8 meg so I had guessed that the tranny was shorted and heating making it worse.

Did you disconnect both primary leads?
If not, and one side of the primary remains connected to the B+ line, and one side of the secondary remains grounded, your ohmeter will be showing charge-up current of the filter capacitors (the meter's internal battery supplying the current).

radio nut 12-08-2013 08:00 AM

Well, the audio transformer is shorted......and thanks to Bill from Moyer's The new part is on its way.
I hope I will be done with this set soon!

decojoe67 12-12-2013 09:04 AM

Just wanted to mention that I get a distinct buzz in the audio with my two '46 RCA TV's when I input the DVD player. Oddly the cheap, lesser quality DVD's like those of early kinescope's shows, have a much less pronounced buzzing. In fact those are the DVD's I mostly use when I want to play those RCA sets.

radio nut 12-15-2013 03:17 PM

well, new transformer in.........and the sound needed adjustment.
but now I will need to do a total recalibrate.,,,,,still has buzz but it is in the local osc circuit and the adjustment causes jitter when I try and adjust it.
It acts dirty......touch it with an alignment tool and the picture freaks out. have to keep barely turning the control and then pull the tool away to see the results.

radio nut 12-15-2013 03:19 PM

The funny part is after removing the old audio transformer it showed about 6400 ohms primary to secondary short.
How many parts in this set are junk??????? So far Most!

old_coot88 12-15-2013 04:29 PM

Quote:

Originally Posted by radio nut (Post 3089794)
,,,still has buzz but it is in the local osc circuit and the adjustment causes jitter when I try and adjust it.
It acts dirty......touch it with an alignment tool and the picture freaks out. have to keep barely turning the control and then pull the tool away to see the results.

Is your alignment tool metallic?:saywhat:


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