Thordarson FLY4

OK this is getting weirder

http://suzaku.live-evil.org/weird.jpg

I had a loose connection when I checked it

It tests at 24 ohms at 12uh. Good/ bad? not sure now

But HVO-5 is the right replacement

So, at this point I'm not sure if the original FBT is good / bad yet, but it's definitely ugly! ( insert 60s movie musical cue here)

The only reference spec I could find was for the replacement merit hvo-5, which may or may not be like the original part, bit confusing.

The fuse for it was NOT blown, that is at least a good sign.

Interesting but looks like you have your hands full. Got to post a picture of the screen when you get it up and running.

Replacement CRT ordered!

The ETF has 3 Merit HVO-5 listed. There's one on ebay but beware there are several cracks in the core. Must have been dropped a few times. At least you can see what it looks like.

I saw that :tears:

If the original one doesn't work, will have to get one from ETF.

Starting Audio section now, it has been worked on before, not very well. :/

Starting to figure out the amp section on this set, as I mentioned, someone has been there before, bad soldering, leads too long, a 1m resistor with 1 end going nowhere, changes from the original design, and, why put in a .15uf cap where it should be .1uf? That has to have SOME impact on operation. :/

http://suzaku.live-evil.org/0301251431a.jpg

AMP rework

http://suzaku.live-evil.org/0301251434.jpg

FBT

It seems that ETM does not have any HVO-5 s in stick after all. :tears:
So if this is bad, it's gonna be a real pain
this this a maggie part?


Replacements are--
Thordarson FLY 4
Merit HVO-5
Stancor A8119
Triad D55
Ram X077

Status update.
Not much to report, did not have much time to work on it this weekend cause of computer problems (RAID-5 headache ).
16L/CP4 paid for, waiting shipment, (thanks ETF! :) )
Ordered the broken core HVO-5 seen on E-bay at discount, may give me a baseline to test what is in the set, not even sure if it's original. And if bad, perhaps with the 2, a good one could be made, failing that, there is a 3rd option.
Will soon start on the main electrolytic capacitors.
There are several candohm resistors mounted in the HV case not shown in the parts locator pages, this is most likely the bleeder network, will need close attention, as will the CRT anode wire that has broken off at the 1m resistor, which will need a new HV resistor.

https://www.youtube.com/watch?v=xos2MnVxe-c


http://suzaku.live-evil.org/0307252316b.jpg

After replacing the main pi filter caps this week, I decided to risk powering it up slowly with 2 new 5U4GBs, and after a while when voltage seemed stable and one paper bomb exploded someplace, not sure where yet I decided to hook the scope up to G1 of the horizontal output tube, well one of the pairs...
https://www.youtube.com/watch?v=NmPhaG1ud38
:D :banana:
All the critical bits are working!
I can now move on to making it good as new!

Furthermore the broken core Merit hvo-5 came today, and my guess was right, it's physically identical to the FBT in the chassis now, meaning I can swap the broken bits from it to fix it, most likely Merit made this FBT for maggie in the first place.

new FBT vs the old..

http://suzaku.live-evil.org/0309251302.jpg
http://suzaku.live-evil.org/0309251304.jpg
http://suzaku.live-evil.org/0309251303a.jpg

It's indeed a merit made unit!
i can swap the broken pats!

the wires in the HV cage is awful. falling apart, needs to be replaced. :tears:

Old windings vs new.

http://suzaku.live-evil.org/0309252037a.jpg

It's Frankenflyback!

http://suzaku.live-evil.org/0310252008a.jpg
http://suzaku.live-evil.org/0310252008.jpg
:D

It's a small world. Here is a link to photos of my Britnay. Maybe some day I will get around to restoring it. Got it from someone in Minnesota about 10 years ago.

https://antiquetvguy.com/WebPages/Th...PhotoPage.html

I do have to wonder why they used 2 6BG6s in this version, and other versions have only 1, it's not a wimpy tube, (20 watts), does it use THAT MUCH power that they decided to 2x it to reduce the load on the tube?

That.s much better! :D :banana:

http://suzaku.live-evil.org/0312251534.jpg

http://suzaku.live-evil.org/0312251535.jpg

Fresh NOS tube!

Some differences between the 16FP4 that was in there and the 16LP4A going in, aside from slight difference in deflection angle and the shape of the bell,which can be adjusted for, is that the 16L has aquadag coating where the 16F did not, also the 16L has a newer type anode connection than the 16F, which it no big deal because the HV line was trashed and had to be redone anyway.
And the final difference is that the 16F had a single pole ion trap where the 16L needs a dual, and I do have a NOS dual one that I hope will work, never used, not sure for what tube it was made for.
https://imgur.com/r3Yt9S5

There is an arrow on the top of it, I assume this points to the screen?

Had more time to get some work in on it tonight, replaced some paper caps checked resistors.

found some that were REALLY bad.
http://suzaku.live-evil.org/maggy-bad.jpg

not sure how well this thing worked with the HOT g1 bias resistors way out of spec. both were about 230k

I also found what blew up when i did the power test, it was the across the line cap 183, no big deal!

If you look at RCA circuits at the time the 16" round CRTs showed up, they also used two 6BG6s and 1B3's. The thought must have been they were pushing the single output setup too hard while scanning that larger CRT. As flyback transformers improved in efficiency they went back to a single horizontal output. And soon after there were stronger horizontal output tubes.

Work is going ahead slowly.

horizontal oscillator seems to be fine, bit a bit low which makes sense sice the FB is not in yet for feedback for it yet. about 28v PtP. on the grids of the HOT.

The vertical oscillator is NOT running, and from what I see it can't If I understand things correctly, the OSC gets power ( T109, V16B) via boost through
r178 from pin one of the FBT, also goes to G2 of the CRT, filtered by C202B.

http://suzaku.live-evil.org/no-vert-osc.jpg
So, if I understand this circuit correctly. long of the short of it is, until the FBT energies and that boost come up, the vertical oscillator won't start.

OK, now things are making sense here! :D:yes:

for the longest time. I could not work out where the horz osc circuit was getting power from when I was testing it!

http://suzaku.live-evil.org/maggy-solved.jpg

the FBT is still not back in, nor is the fuse.

so where is that 6SN7GT getting bias from?:scratch2:

Then today. I changed all paper caps in the area, and DING! IT HAS STOPPED WORKING!
Bad caps!
:nono:
C186 was so leaky, that it was bleeding enough power to start the oscillator.

I did manage to confirm it, I bypassed things a bit so that line to the horizontal oscillator circuit would get power, and it came back good and strong at 40 PtP. :D
Not quite ready to put the FBT in yet, want to clean up the area a bit, and replace the crappy wires in there.

More things uncovered, the damper is DEAD, this thing must be hard on them new ones ordered.

Latest status update.
When I first got this set, the cover was off of the HV cage and the 2 HV rectifier tubes were out and set aside, indicating someone was trying to debug a HV problem and gave up and left it to sit for untold years.
This would not have mattered if it worked or not, since the 16FP4 was worn out and most likely could not show a picture anyway.

The flyback transformer was in a very questionable state, partially to exposure to the elements and the others due to age and the old wires to it being old and full of splices, the old one may or may not have been OK, but since I had a NOS one, why risk it.

With the flyback out, a test of the horizontal oscillator seemed OK, but a bit of a mystery because I was not sure where it was getting power from w/o the flyback in circuit, this turned out to be VERY leaky paper caps, that when replaced, the horizontal oscillator stopped.
A quick bypass of the area to power proved this, good strong horizontal oscillator.

So last night, I started to replace the FBT wiring with new 600v lines, staring with the #5 line to main bias, and #4 to the plate of the damper, link 4 & 5 together, and power up, then the horizontal oscillator SHOULD have started, this did not happen...
Odd, why?

Checked pin 5 of the 6W4GT, good positive voltage, then pin 3, cathode, negative 60v... that aint right!

Not right at all, grabbed the one other one in my hoffman set, BINGO, positive voltage on the cathode, and the horizontal oscillator started.

The bad 6W4GT is most likely the original cause of the HV problem with the set.
New one on the way, plus new 6GB6GTs.
In the meantime will replace the other FBT lines and get the new one in, and replace more caps.

It might be a bit silly looking once I get a raster/ picture up on this little test CRT! :D

http://suzaku.live-evil.org/0324252054.jpg

Things are a bit different from the schematic, which is not unusual.

http://suzaku.live-evil.org/maggy-bad.jpg (re-using this picture)

C178 is not hooked as shown on the left of C185 but is on the right side, and the other is hooked to ground as for the EP4, R225 is testing at 1m I will assume its bad, as I cant read the bands on it, the 4.7 ohm ones test OK, but will be replaced anyway. the entire area was very dirty and needed lots of clean up

So when will we see the first picture

I'm still waiting for the new damper (6W4GT) + 2 new 6BG6GTs to show up, track SAYS Friday, but who believes USPS these days, the FBT hook up is almost complete, save for lines 2 & 3, the sockets for the 1B3GTs were cleaned as was the board they were mounted to, there is still some rust that I will cover with corona dope, the 3 500pf caps had some cracks in the surface and was coated with corona dope, the 3 resistors in the doubler circuit will be replaced tonight ( 2x 4.7 & 1.5m), I have a new 1m HV on the way, due here Fri, ( 588-MOX-2N-131004FE ) .

So, given that all parts come when they should and things go together well, I should be doing a HV power up this weekend, and if that works, a go for raster on the test CRT.

http://suzaku.live-evil.org/0327251948a.jpg

The HV doubler circuit before having the old resistors replaced, lot of bad solder work :(

http://suzaku.live-evil.org/0327252050.jpg

new resistors in,, don't have the NEW HV 1m one yet.

Yup that looks better

All HV parts are in now

http://suzaku.live-evil.org/0328252209.jpg

Boy its crowded in there! :D

http://suzaku.live-evil.org/0329250310.jpg
http://suzaku.live-evil.org/0329250315.jpg

gotta wait for the silicone to cure now.

Why did you use a special HV resistor? A regular one would be fine.

And Bon Scott of AC/DC spoke, " "l LET THERE BE HIGH VOLTAGE!!!! And thus it was commanded, and thus it was done! :banana: :yes:

http://suzaku.live-evil.org/0329251102.jpg

Turns out that both 1B3GTs were also dead, had new on hand, so no biggy.

It most likely would have, but if you look at the pic of the old resistors, what was in there before was 2 rather large 500k resistors in series, that had broken, I had no ref to what size they were power or what, but I did not have anything near that size physically in my stocks, so if I was going to have to order something, I chose to spend the extra $ for a HV resistor.

Replacing a few more caps before i try to get a raster, now that HV is working.

this one was REALLY bad!
http://suzaku.live-evil.org/0331251435.jpg
tests at 68pf :O
slightly dif from what was shown in the schematic, C163 off the center of the vert center pot, but it being bad would no doubt had a drastic effect on the sweep.

http://suzaku.live-evil.org/no-vert-osc.jpg

Recapping almost done!

http://suzaku.live-evil.org/0401252124a.jpg

not sure why that yellow cap was stuck in there :O

That extra sprague atom cap that someone put in there has me a bit confused as to why they did it, they put in that big yellow cap (40uf) in parallel with C200B, (30UF), which did not really test bad, 37uf, a bit leaky, both C200A C200B (30uf) are in the bleeder network, 200C (10uf) is in sweep tests at 14uf.

Why did they add the extra cap?:scratch2:

And there is Raster!

http://suzaku.live-evil.org/0405250052.jpg

No video yet...

but full sweep!

Dead IF it seems ...

more new tubes, and time to check resistors in the IF area, most likely all the cathode resistors are bad. Have seen this over and over!