[morzh]

Boy that ballast tube gets hot....first I thought something was heating and then I realized that that was the ballast and the enamel I used (for gas ranges so it is heat-resistant) gave a little smell. Empty scare but....can never be too careful.

I will tend to the big green dude tomorrow some more, I've done enough today. Some serious voltage measurements plus alignment. I think it is a bit out of it, it behaves very much like the other AA5 out of alignment....or any other radio....

OK, tomorrow then.

[morzh]

Well, tonight I tried aligning the green dude on the table and I realized that 1) it does not help whining, AC noise and proper oscilaltion failures where I very quickly fall into the whining and distortion barely having touched the trimmers.

I also noticed that AC noise gets reduced quite a bit when I touch the chassis.
Then I remembered that I am dealing with a separate RF common and chassis, and there should be a cap linking them together for AC. I looked at the sch, there was that cap there, 0.2uF. Then I measured the capacitance (there are no other paths there so it should measure exactly as this cap's capacitance) and instead of expected 0.2uF I had 0.7nF or so, that is - stray.
I started looking for that cap where the assy diagram shows it - it was not there.
So, I connected a 0.22uF cap across and then I saw the noise going down and I was able to align the set.
The sensitivity went up immensely, and now I have my local station received as it should be, with just with a pigtail for the antenna, with volume loud and clear and enough to rip the cone out of the speaker if I let it.

I also checked the SW band and it is working fine, also with just a pigtail for the antenna.

It is playing now quite nicesly as I am writing this.

There is that residual AC noise, but I could see someone soldered an extra piece of wire to lengthen the grid cap wire for 6Q7, and this is the shielded wire so a significant piece of it is no longer shielded, and when I move my hand close it picks up more noise, so I think I might use a piece of a braided shielded wire instead of what is there now.

All in all it is working. I might try to realign the band so the pointer shows exactly what it should....maybe. It is close enough.

I think I might clean both treble and volume pots, there is some scratchies when I rotate them.
I thought of cleaning the tube panels and the band switch but the switch operates quietly and there seems to be all fine with contacts in the tubes.


They are playing "Classic gas"...sounds nice.

[Arran]

By the way, I found someone who is making reproduction electrolytic condenser cans. It's debatable whether it's worth buying them in this case over renovating some old ones, but it's obvious that some effort went into producing these:

http://www.ebay.com/itm/New-Production-1...1014697519

I know all about those capacitors to couple the B- to chassis in an AC/DC set, if it isn't there the set will motorboat and howl like crazy. Sometimes they are paralleled with a 220K ohm resistor. I'm actually quite surprised that they did not produce radios of transformerless design in the former Soviet Union since it was RCA who developed the high voltage 150 ma series string tubes, given that they are cheap to build, and that the regime was somewhat indifferent to safety in many ways, and they liked to copy RCA.
Regards
Arran

[morzh]

Arran

yes it was motor-boating and howling and I immediately thought of that cap. And I knew I recapped every cap that was there. So it was a surprise when I found the cap wasn't even there; I know the radio was repaired before, but then it would barely work after that; I could not stand it first when I heard it play, so why would anyone repaired it and then remove this cap.....is beyond me.

As for the repro electrolytic cap tubes, indeed they look nice and would definitely augment the looks except that it comes to 15 bucks a pop after shipping and two of those would amount to half of what I paid for that radio. Considering it is not a Cadillac of a radio in the first place.....you know, I will forgo it for now until I get to rebuild something that indeed requires immaculate appearance and short of doing that to E.H.Scott I am yet to see a radio that truly requires that.

For the AA5 and the Soviet Union.....it could be a safety thing, after all one thing is when you get zapped from 110V and another when it is 220V.
But, Europeans did build those; I wrote about a Latvian VEF AA5, it is exactly the same as any of AA5 Mains-powered units schematic-wise and the tubes' lineup is the same.
When the USSR inherited VEF, I think by that time they did not make any of those, and if they did, I am sure the safety concerns were voiced, and safety was taken seriously, at least the obvious one like being killed on the spot (no, not asbestos and such).

I could ask on the Russian forum whether anyone saw AA5 of Soviet production. I have never seen any.

[Arran]

I knew that there were European made AC/DC sets, I have a European built Phillips downstairs for example, the French and British definatley had them. I was just wondering why the Soviets may not have attempted to build and market an AC/DC or series string set? I noticed that the Soviet radio industry, particularly the tube side, tended to emulate RCA, like they purchased a license to build metal octal tubes for example. RCA was the pioneer in developing 150 ma tubes that added up to the full 120 line voltage in North America, things like the 35Z5, 35 and 50L6.
I just thought that some may like to see those replicas, I would guess that you could combine the shipping to knock the cost down, but then again I could also build my own Mershon knockoffs out of some plumbing parts from the Home Depot
Regards
Arran

[morzh]

One of the last touches - the volume pot behaved pretty bad so much so that when I measured it it was so patchy I did not have high hopes for the recovery and I posted on the parallel forum for the org part numbers (mine seems to be P26111 but it is very much obliterated so I was not sure I read it right) and replacements.

Meantime I blasted the pot with Deoxit, went away to a friend's birthday, had a blast, ate good ethnic Caucasian food (well, Brooklyn is at least good for that, otherwise I don't like it), came back, mixed some lithium grease with Deoxit, spread it by applying a little speck to the wiper, and, voila! - the scratch is gone and it is smooth as a baby's you know what. I totally did not expect it to work that well as it was really patchy and scratchy.

Now it's the treble pot's turn, it is a much better behaving pot, there is some scratch at the bass end, plus it is not volume so it is not that sensitive....still I want to repeat the experiment.

[morzh]

Well, fixed the pot, cleaned the case with GoJo, lots of grime, the cloth became dark brown, put the radio together.
It sings nicely and looks decent enough, I just have to figure how to fix that missing piece of veneer, and some black spots....they kinda blend in.

Terry told me there is some thing that can be melted on to resemble finish. I wonder if this is a possible venue.


The only thing I do not get is this: once the tubes warm up and the dial lights get dimmer which they should, I stop seeing the arrow (which is the semi-transparent strip in otherwise black rotating disk. And the dial itself in not lighted too well, I can only see it in a total dark. And I am not sure why as the lamp sockets, they only fit one way and all three of them are installed and all three lamps are on. A minor thing......but I'd like to see the dial.

[morzh]

Some pics

   
   
   
   
   


This is the way I got it.

[morzh]

Now the chassis after some cleaning.

[morzh]

Underbelly.

   
   
   

With speaker.

   
   

[morzh]

Assembled.
I used some GoJo, nothing else. Will need at some point to repair that missing piece of veneer on top.

   
   
   
   
   

[morzh]

Just have noticed: need to rotate that cap on the right, otherwise it says "Philco".

Special thanks to PouhPow for the can caps.

[jerryhawthorne]

Mike a really nice job on that chassis top, looks like new.
Jerry

[morzh]

Thanks Jerry,

Naval Jelly did the trick. Windex only took off the loose part, but then there is that embedded part that even alcohol barely was able to take off and some pitting was still left, and while tending to the rusty spot I noticed how nice the metal around it looked when I rubbed it a little so I took a small portion of the Jelly and cleaned the parts where the other cleaners did not work. Then washed it with alcohol moistened paper towels.

Mike.

[Arran]

I think that the bulk of the cabinet, including the top, is covered with a species of Rosewood veneer, possibly Kingwood. I don't know where you would find a scrap of it to patch the chipped area though.
Regards
Arran