a real challange? - Page 31 - Videokarma.org TV - Video

Electronic M · #**451** 08-04-2020, 10:34 AM

Quote:

Originally Posted by Yamamaya42

ooops!
I missed a couple

I thought they were Mica :/

I plugged it in tonight and it went FOOM! :O

https://imgur.com/5O76o0O
https://imgur.com/N9UhRBD
one of the 2 input caps went up in smoke, and took the input plug with it, unwelded it from the back.

https://i.imgur.com/xaPGUjl.jpg
so I had to feed a line direct in and add new caps

https://imgur.com/8XubId2

back running again

My policy on anything pre 1960 is to look up all domino caps on the schematic and replace all rated at 1000pF higher. 1000pF is the threshold where dominos go from usually mica dielectric to usually paper dielectric. The paper dominos also usually have a white dot on them...If there's not a 9 in the capacitance and the capacitance is close to the paper cap range I also consider changing caps.
I've seen blown micamold paper line bypass caps that blew before my ownership before... always a mess.

Watching Card Captor Sakura I see.

Yamamaya42 · #**452** 08-04-2020, 10:54 AM

Quote:

Originally Posted by Electronic M

My policy on anything pre 1960 is to look up all domino caps on the schematic and replace all rated at 1000pF higher. 1000pF is the threshold where dominos go from usually mica dielectric to usually paper dielectric. The paper dominos also usually have a white dot on them...If there's not a 9 in the capacitance and the capacitance is close to the paper cap range I also consider changing caps.
I've seen blown micamold paper line bypass caps that blew before my ownership before... always a mess.

Watching Card Captor Sakura I see.

Well, I started to run out of LD movies to play while testing, so I went to my original stock of CCS LDs .
And, DO have them all, as I fansubbed the entire series in the 90s

Yamamaya42 · #**453** 08-12-2020, 07:27 AM

I found a " Dunsel "

An old Blonder Tongue Ultraverter Dunsel to be exact!
https://www.ebay.com/itm/20151173538...m=201511735381

Obviously, it can never be used for anything even if it ever works again, but it's just too unique not to have!

old_tv_nut · #**454** 08-12-2020, 10:15 AM

Well, just for grins and giggles, you could use it to convert a digital UHF to VHF and then receive it with a digital receiver or converter box.

Electronic M · #**455** 08-12-2020, 10:45 AM

If it is still working and you have an agile modulator transmitting at UHF you could hook it to your 630 clone or your Setchell (or was it Stromberg?

) Carlson.

I have a few of that things cousins near my work bench. I forget if their gutted or not...I've got roughly 4-6 UHF converter and or VHF antenna amps and 1-2 or the ones I bought were gutted by their previous radio collector owners... one day I'm going either built an AM transmitter in or a clone of a vintage tube RF modulator I bought from the ETF a few years ago.

dtvmcdonald · #**456** 08-12-2020, 03:24 PM

Quote:

Originally Posted by Electronic M

If it is still working and you have an agile modulator transmitting at UHF you could hook it to your 630 clone or your Setchell (or was it Stromberg?

) Carlson.

Convert it to output on Ch. 1 and feed it to your pre-war TV.

Electronic M · #**457** 08-12-2020, 03:37 PM

Quote:

Originally Posted by dtvmcdonald

Convert it to output on Ch. 1 and feed it to your pre-war TV.

Pretty sure neither I or the OP have a Pre-war TV. I'd like own one some day but given they tend to go for classic car money and I'd rather have a classic car for the money it will probably be a while before I own one.

old_coot88 · #**458** 08-12-2020, 04:07 PM

Quote:

Originally Posted by Yamamaya42

I found a " Dunsel "

An old Blonder Tongue Ultraverter Dunsel to be exact!
https://www.ebay.com/itm/20151173538...m=201511735381

We sold a gadzillion of those back in the day. Biggest problem with 'em was intermittency of the wipers on the tuning rings. Cleaning and re-lubing usually helped. Used a 6AF4 and 6AB4. The one tube version had just the 6AF4. Don't recall ever replacing a tube.

dtvmcdonald · #**459** 08-12-2020, 05:28 PM

Quote:

Originally Posted by Electronic M

Pretty sure neither I or the OP have a Pre-war TV. I'd like own one some day but given they tend to go for classic car money and I'd rather have a classic car for the money it will probably be a while before I own one.

I meant to say "early post-war".

You can afford lots of Hallicrafters T54s with Ch. 1. They make good pictures:
Hint for them: buy a cheap 4" 230 volt AC fan and put it on the RF coil ...
it works nicely on 122 volts and is quiet as a whisper.

I assure you however that pre-war US TVs can be had for reasonable prices
if you are willing to settle for a TRK120. You're thinking British.

Yamamaya42 · #**460** 08-12-2020, 07:28 PM

Right now, my FADA is still in direct A/V input mode, as I had trouble with doing the IF alignment procedure, tried more than once, where as the tuner DOES work, there is heavy RFI on channel 3, which is seen to a lesser degree on 4, and adding a rf amp helped even more, it did not make it go away completely, but when I did get a BT modulator for chan 7, I did find it free from RFI, but the tuner has contact problems on THAT channel

The instructions clearly says set to channel 9 when doing IF alignment on this set, but someone said that any chan can be used ( this is also reflected in later instructions for other sets ) , since the osc tube is removed and the signal fed in the aunt input.
For example, I just ordered a BT modulator for chan 11, if I can confirm that 11 works OK w/o any problems. Can't I use 11 in the alignment procedure where it says to use 9? will it make any difference?
https://i.imgur.com/HpMK2wJ.jpg

But then what to do with the BT mod chan 7? use it on my CTC-16XL? :p

interesting idea.
But it too has minor IF problems, that I don not have the equipment to adjust,

nothing really THAT bad, just red bleeding that will move with the fine tuning, perhaps I will try to fix SOME day!

But for the stromberg carlson x-21 , I do like the idea of feeding it UHF and having the ultraverter convert for it! I just have to be sure to find a modulator that IS uhf and not CATV . :p

Tom9589 · #**461** 08-12-2020, 08:38 PM

Many moons ago, I had a Philco UHF up converter. I used it with my 1076 B&K TV Analyst which only had VHF coverage. Set the 1076 to channel 4 and hook up the Philco and you had channels 14-83 at your fingertips. When I got a 1077, I got rid of the Philco.

I particularly remember the precision vernier for setting the UHF channels. It even had a hand typewritten scale which told you the exact setting for each channel.

Electronic M · #**462** 08-13-2020, 09:57 AM

Quote:

Originally Posted by Tom9589

Many moons ago, I had a Philco UHF up converter. I used it with my 1076 B&K TV Analyst which only had VHF coverage. Set the 1076 to channel 4 and hook up the Philco and you had channels 14-83 at your fingertips. When I got a 1077, I got rid of the Philco.

I particularly remember the precision vernier for setting the UHF channels. It even had a hand typewritten scale which told you the exact setting for each channel.

So you fed the CH4 output of the B&K into the output of the UHF converter and the converter worked backwards and spit UHF out of it's input?....I never thought of that but the principal seems sound. This gives me some fascinating ideas for UHF agile modulator add-ons to my existing VHF modulators.

Yamamaya42 · #**463** 08-13-2020, 11:04 AM

I will try to put the final touches into the FADA this weekend, which will involve.
Adding a power switch, as this was part of a combo unit, it never did have one. :O
Adding a A/V bypass relay circuit so I can easily switch from direct to RF input, to be powered from 6v filament voltage.
Mount the volume in a decent location with a knob.
Try again to do the IF setup, most likely on channel 11 this time, given that the BT modulator on the way is for 11, most likely just need to adjust the noise traps and 1st IF, will try antenna input first, but if that still gives problems will try direct input on point E on the tail end of the mixer, and if I STILL can't get the IF set up that way, I will just stick with direct input.

As it was mentioned before, I should not HAVE TO set to channel 9, or any specific one to do this with the osc removed...

And finally, once I have done all I can, ( I hope :P ) take it section by section to it's final location to re-assemble, for one thing that's clear about this set, you do NOT move it when all together, this is more so true now that I don't have the chassis bolted in the cabinet, I deliberately measured and cut things so that there was an about an ½ inch gap between the cabinet bottom and the chassis, I have it sitting up on the bolts for cooling.

bandersen · #**464** 08-13-2020, 11:55 AM

Quote:

Originally Posted by Tom9589

Many moons ago, I had a Philco UHF up converter. I used it with my 1076 B&K TV Analyst which only had VHF coverage. Set the 1076 to channel 4 and hook up the Philco and you had channels 14-83 at your fingertips. When I got a 1077, I got rid of the Philco.

I particularly remember the precision vernier for setting the UHF channels. It even had a hand typewritten scale which told you the exact setting for each channel.

I believe that would be the Philco G-8000. They show up for sale now and then.

https://worldradiohistory.com/hd2/ID...-Page-0021.pdf

Kevin Kuehn · #**465** 08-13-2020, 02:00 PM

Quote:

Originally Posted by Electronic M

So you fed the CH4 output of the B&K into the output of the UHF converter and the converter worked backwards and spit UHF out of it's input?....I never thought of that but the principal seems sound. This gives me some fascinating ideas for UHF agile modulator add-ons to my existing VHF modulators.

I think you may be overthinking this.

More likely used the 1076 as a VHF signal source into the UHF converter, in order to make the 1076 signal usable on UHF tuner TV's. I can't imagine what else what would have been going on.