Adding Composite Input (Capacitor Question)

[ARC Tech-109]

I'm sure the 1N914 is better overall but the problem seems to be riding the crest of the waveform with the small signals and its higher forward voltage. Once I went to the 6JU8 the chroma response was far better. This set never had what I'd call "stellar" color, it was good but maybe I'm spoiled by the sheer number of broadcast monitors. Dunno, it uses the 6HS8 as an X-Y demod and from what I remember this design was an "acceptable" lower cost design albeit not as accurate as the R-Y B-Y or I/Q with what appears to be a slower phase response. Good enough for the 1970's I guess when everything was burnt orange with splashes of primary colors here and there.

So everything was working well last night when I shut things down around 0400 central, just before this I dribbled a little hot wax down the IF coils to lock the slugs in place then checked the response curve and picture once again and everything was on the mark.
This afternoon I resumed my work as the outside temps went to the low 90s with mid-60 dewpoints, fired up the set and noticed a really bad picture, checked the IF response and found it had a very sharp peak going just above the picture carrier that wasn't there last night after I dropped the wax.
Ran thru the IF again and locked the slugs in place and everything is holding at the moment, I'm wondering if this might be a moisture issue as the humidity went from roughly 55% to almost 80% over the past day. Not much for air conditioning unless it's oppressive like this afternoon.

Did verify the AGC pot with an analog Triplett 630-NA meter and found it has several "scratchy" points along the travel so it's another trip on the motorcycle to AxMan Surplus in St. Paul as they have bins of these. Minneapolis/St. Paul area used to be a big tech hub during the early computer days with the likes of Sperry-UNIVAC, Honeywell, Control Data, ADC Telecom and IBM in Rochester and had two dozen surplus stores full of this stuff. By the mid-80's only a few remained and today AxMan is the last one standing after almost 60 years in business, they have enough inventory in that building to go another 60 years and it's always busy.

I got the Motorola R2670 monitor during my days at the regional service depot, employees could buy their test equipment at cost and pay for it out of salary. I optioned this one with the everything I could and it's served me well. Other bench test equipment includes a Tek 475 scope, Motorola R1011B 40 amp power supply, along with the various Bird RF meters. TV service is done with a late 60's Tek 453 scope originally from IBM, it has nuvisters on the front end and can survive a kilovolt hit to the input jacks. I also have the Heathkit IG-57A IF sweep/marker and B&K 1246 dot/bar generator plus 466 and 467 pix tube analyzers. Yes I'm on the trailing edge of 1970s technology.