Blonde Andrea T-VK12

[decojoe67]

In all my years of being into vintage TV's I never saw that model in blonde! It's a scarce model for sure, although the value would probably be close to the mahogany version.
I actually found an excellent mahogany version at an estate sale many years ago for $50 and sold it soon after for a very good profit. It's a massive tabletop set, but a high quality set for sure. Enjoy it and good luck with the resto.

[IsthmusTV]

Hi all,

I've been working on this set in fits and starts. This weekend, I finally finished the recapping. I decided to mount the electrolytics under the chassis because there was plenty of room and some of the cans are hard to get at:


I replaced every paper and elecrolytic cap except one, C7. It's a 2 uF at 25 Volt electrolytic across the output of the 6AL5 ratio detector. It's mounted in a tube of copper sheet and fastened to the chassis with a screw under a terminal strip. I'm guessing that this is for shielding, but it almost looks more like a heat sink. Anybody know what this is? Do I need to keep this copper thing in place when replacing it with a modern cap? I think I'll leave it in place for the initial power up.


I replaced the disintegrated power cord. It had a molded strain relief, so I used a rubber grommet in the hole.



I may have problem with a couple of these peaking coils. I can't seem to get a stable resistance measurement through the two on right:


I'm very impressed with the quality of the resistors that Andrea used. I have yet to find one out of spec.

Well, that's the progress to date. I hope to have some time this weekend to do a controlled power up with the CRT in place.

-Clark

[Kevin Kuehn]

Great work, Clark. Not sure what to make of the copper shielded electrolytic. Maybe because the old ones didn't have the neg lead tied to an outer metal can. But I don't recall seeing that practiced on any other ratio detector circuit. Possibly Andrea was just being very picky with their design, trying to keep hum out of the audio. Although it seems copper would be more of an RF shield than magnetic.

[wa2ise]

Assuming you get it restored, you could modify a TV modulator to output on channel 1. You want the modulators that use a 4 legged metal module used to create channel 3 or 4. Remove it, and install a 15MHz crystal in its place, so it straddles the modules old ground connection. And you may need to add 4pF caps, one cap for each crystal lead, to get it to oscillate. This in addition to existing caps, so the total would be about 8pF. Seems that lower frequency xtals need bigger loading caps. Likely to yield a similar reactance at the new freq like that with the old cap at the old freq. Those of you who have experience in xtal osc circuits would recognize this, probably better than I would.

[IsthmusTV]

Thanks, Kevin. Yeah, I think that shielding to prevent hum in the audio sounds very plausible. I'll probably just install a modern cap and leave the old one in place. If I have any hum problems, I may try putting the new cap inside the shield.

And wa2ise, I might give that a try some day. I remember reading your thread on the topic a while back. It would be kind of neat to have the Andrea tune in a signal on channel 1 after all these years. Since the set was made in 1948, it probably missed the opportunity to actually receive one over the air.

-Clark

[KentTeffeteller]

This is a neat set. A beautiful Blonde. Continuous Mallory Inputuner/Inductuner. Channel 1, Post WW II FM Band, AM, and above all a very desirable, uncommon high end brand. An Andrea. Which used to be known before as FADA Radio. F.A.D.Andrea. A last gasp Channel 1 set with modern FM. Will be a nice restoration when you get her complete. I love this set. An early TV fanatic dream. Very high quality when new. And Andrea build quality was tops.

[IsthmusTV]

Well, first power-up went way better than I had even hoped. Using a metered Variac, I was rewarded with no bad noises, smells or smoke. And at 115 Volts, I was rewarded with FM radio music in the speaker and a raster! The 12JP4 has the usual ion burn in the center, but no ion trap to adjust!


I hooked up the cable box with output on channel 4, and it didn't take long to get its first coherent image in probably several decades:


Vertical and horizontal lock are rock steady. I made all the usual adjustments. I ended up getting the vertical linearity somewhat better than in this screen shot:


The Inductuner is a bit scratchy, but the best picture and sound coincide!
Here are a few more screen shots.





I'm still marveling at how well this set is working after shot gunning all the caps. The only tubes I've tested are the horizontal output, HV rectifier, damper and both 5U4's. Now, I'll test the rest of the tubes and clean all the pots. Oh, and the AM radio works fine too!

-Clark

[wa2ise]

You have earned a dancing banana!

[Username1]

Originally Posted by wa2ise

You have earned a dancing banana!

ha ha ha - I like the way you put that.......

.

[Titan1a]

Very, very nice! I give you 4 gold stars. Bravo!