a real challange?

[Tom9589]

Yep, that was the unit I had. I liked the line in the ad which said each unit was individually calibrated. Didn't use it much, but when I did, it was really handy. The 1077 could provide the UHF signal, but not with the accuracy of the Philco G-8000.

[Yamamaya42]

https://imgur.com/fnI3Cvj
FADA in final location.

made last attempt to do IF adjustment, wont know if it worked until BT mot chan 11 shows up.

A/V bypass relay is installed and working

[Yamamaya42]

done, almost waiting for volume pot.

top view
https://imgur.com/qrTbhTb

They are NOT here... yet! :P
https://imgur.com/rGoq2pW

[Yamamaya42]

Well, I SHOULD HAVE had the Blonder Tongue Micm-c modulator (chan 11) today, but due to a certain nameless someone's sinister sabotage of the USPS lately, it is NOT arriving on time, like many other mailed items lately, I now have no idea when or if I will ever get it.

No way to know if my tweaking of the IF section worked or not yet...

who knows when it will get here now... :/

One thing I DID notice when I tried ( I saw this before, ) if I follow the setup exactly, and set the voltage gain as the want on the “contrast” to -3v, I got nothing at the testpoint, no matter what freq I put in, I had to back it away from -3, until I could see some sort of reaction to what I was feeding into the tuner, then I went and adjusted the traps only, the 1st IF coil was already tuned to the optimal setting, which I set by visual long ago.

[Yamamaya42]

The BT modulator for channel 11 arrived, damaged , but fixable.
it's working WELL on channel 11, no audio in the picture and looks like the IF setup worked this time, well, as well as a n00b like me could do it!

https://www.youtube.com/watch?v=w-t2...ature=youtu.be

[kvflyer]

Yes, success! Looks great.

[Yamamaya42]

That's not to say, that it won't benefit from more work, like a tuner rebuild, but since I never did such a thing, if I were to try, it would most likely never work after if I did.
something like was done here.
http://worldphaco.com/uploads/621TSARTICLE.pdf
half of the 1500 pf caps in the IF section are still original, ( same caps are used in tuner ), and all the 270 pf coupling capacitors are still original, some people said to replace, others said only to replace if they were giving problems, I did buy all new ones, but opted not to put them in, cause I did not want to face a total end to end IF alignment.

Granted, its not working at optimal condition tuning wise, but for its age, it is working very well and usable!

[Electronic M]

IF and video response look good. These sets could resolve the video carrier out to 4.5MHz which was better than many sets of the day and better than most 1954 and later monochrome sets (which usually rolled the IF off above 3 MHz to hide the dot crawl of the chroma subcarrier. Even if it isn't all the way out to 4.5 if it can resolve details finer than the subcarrier dots you're winning against other sets around that vintage.

The left ringing and the occasional retrace lines could probably be fixed if you want to.

[Yamamaya42]

Originally Posted by Electronic M

IF and video response look good. These sets could resolve the video carrier out to 4.5MHz which was better than many sets of the day and better than most 1954 and later monochrome sets (which usually rolled the IF off above 3 MHz to hide the dot crawl of the chroma subcarrier. Even if it isn't all the way out to 4.5 if it can resolve details finer than the subcarrier dots you're winning against other sets around that vintage.

The left ringing and the occasional retrace lines could probably be fixed if you want to.

The left ringing is most likely due to that I have not touched the horizontal linearity adjustment yet on it, there is a barely perceptible squeeze on the extreme sides, that I have not tried to play with yet, I do have a DVD with a linearity adjustment pattern on it, but it's a nightmare to navigate and pause on to use
As for the retrace, I still may experiment with adding vert blanking to be able to turn up brightness w/o having it show up.

[Jon1967us]

Is the point that there's no or much less interference on UHF, if you use that to transmit in the house, vs VHF?

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.

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.

[Electronic M]

Originally Posted by Jon1967us

Is the point that there's no or much less interference on UHF, if you use that to transmit in the house, vs VHF?

Nope. My point was they had an antique UHF converter designed to add UHF to older sets that didn't come with UHF when new, and they could still use it if they transmitted UHF.
Interference varies from place to place depending on a number of factors. UHF could be better or worse depending on where you are, what UHF DTV channels are transmitting* in your area, what type of noise is produced by the switch mode supplies you and your neighbors are using, atmospheric noise, etc.

My advice to anyone planning to transmit their own low power analog is start with an agile (agile meaning you can change which channel it transmitts on) modulator, a DTV converter box with signal strength and manual RF channel selection in the menus, and an analog TV.
*You don't want to transmit on a channel that a local DTV station is using as you'll interfere with each other (the UHF band tends to be more packed with transmitters, but ATSC 3 is changing that). I typically use my Zenith DTV converter boxes to figure out which channels have active DTV stations and avoid those channels (I need to get an ATSC 3 capable box to check for those signals too). The static on an analog TV can tell you a bit about what noise exists on what channels too...once you have an idea where other transmitters and noise exists pick something that has the least of that, set your transmitter to one of those promising channels and try it out...If it sucks try a different channel.

IMO The fixed channel modulators are something you get after you've tried a channel with the agile modulator and know it's good... Otherwise you risk undiscovered interference making the fixed channel modulator as useful as a door stop.

[Yamamaya42]

As for the remaining minor annoying horz issue, mainly the slight fold-over / ringing on the left, there IS a way to adjust it, but it's nearly impossible to do in this set due to the 12 inch screen, and the location of the adjustment, RCA just did not think ahead here.

On the osc transformer, there are 2 adjustments, B2 (on SAMS) HORZ FREQ, which can be adjusted from the back, and B1 HORZ PHASE, which can only be reached from under the chassis.
https://i.imgur.com/oFR1Zab.jpg

The horz osc transformer can be seen here, the metal can at the back opposite the vert output transformer.
As this adjustment is best made with the CRT that is being used in the set, and after all other respective geometry set, ion trap, focus coil and so on, and since it depends solely on the cabinet for safe CRT support in this case, there is no way to reach that adjustment once the CRT is set in place.

It seems that the only option right now would be to cut away a section of the bottom of the cabinet so I could reach in and adjust it, but this will be left to a future date.

As for the nonlinearity, IE, the very slight compression on the L/R sides, not sure if that's normal or not now with the set, the horizontal linearity adjustment DID have some effect, but not much on the extreme sides, however, there are 3 caps I have not changed yet.
https://imgur.com/vrj7U91

The pair of 220pf only show up on the 12 inch FADA version, and I can only assume are there to widen the sweep, and the 56pf in the yolk, these may or may not be out of tol, and who knows what effect it may be having.

But at this point, I deem the horizontal issue a minor nuisance at this point, not worth pulling the thing apart to deal with, will add it to the list along with the retrace mod for something to think about later.

[old_tv_nut]

Linearity adjustment is intended to affect one side of the picture with respect to the other, not both sides compared to the middle.

Depending on the sweep angle, a design may have an "S" capacitor to compress the sides because wide sweep angle tubes tend to expand them. I don't think that would be the case for this set. A slight edge compression may be normal for this set and tube.

[Yamamaya42]

My FADA is still working fine without problems so far, in spite of the oddly low measurement on the primary winding of the FBT, it's been run many times for hours with no release of any “magic blue smoke” or red-plating on the HOT, so I'm not sure what to make of the low reading, or if it really meant anything.
But I still have the NOS replacement on hand just in case.
The only thing I HAVE noticed with the set is that the IF section is still not optimally tuned, and given how old it is and what it has been through, AND, how hard this one is to tune in the first place, I'm not surprised, but I can tune in a decent picture and audio, and if needed, flip to direct A/V input.

One thing I am impressed with is how much audio power it can generate, the 6K6GT can easily overpower the little 5w 6x9 speaker I put in there, I now wish I got something a bit bigger!

[Kevin Kuehn]

For the ringing on the left hand side take a look at RCA application note AN-151 which is available in the archives of the Electron One website. There's a wealth of historic information stored in those archives. Anyhow, AN-151 breaks down what can be the cause of that ripple and hopefully you can narrow it down to beam current modulation or modulation of the scanning current. Here's the link to the document.

http://www.one-electron.com/Archives...20Circuits.pdf