View Full Version : Admiral 24A12 restoration


bandersen
01-09-2010, 12:26 AM
What a surprise - I scored another Admiral set :banana:
They must have been very popular in Chicago back in the late 40s. I find more of this brand than any other.

This is the sister set to the very similar looking 20X122 which has a gold bezel and single chassis while this set has a white bezel and a split chassis.

This is the first set I've picked up from an active smoker.
I didn't think much of it when I picked it up, but after I got it home I really noticed that both it and I stunk :yuck:

He had it running when I came to pick it up - ugh. I switch it over to channel 6 (low power analog station) and heard some nice audio - even without an antenna, but no picture.
The price was right though so I brought it home.
http://farm3.static.flickr.com/2716/4258083426_ff13d56487.jpg http://farm5.static.flickr.com/4041/4258683782_af520b6ed4.jpg
http://farm5.static.flickr.com/4045/4257924297_5d940db2ca_b.jpg

First, I cleaned the knobs. One, it's easy. Two, I just picked up some Simichrome and was curious to try it. Man, this stuff is incredible!
http://farm3.static.flickr.com/2762/4256084498_68f04c42bb.jpg http://farm5.static.flickr.com/4013/4258746412_da95b62dd0.jpg

Only one scratch in the cabinet that I've noticed.
http://farm3.static.flickr.com/2770/4258683226_5aa1d84746.jpg

I've only done a little cleaning, but the bakelite 'grain' looks really nice.
http://farm5.static.flickr.com/4059/4258059481_c9a9cb0b11_b.jpg

It appears that someone worked on this set in the mid-80s based on the date codes on the caps.
http://farm3.static.flickr.com/2763/4258085266_34646abe99_b.jpg http://farm5.static.flickr.com/4063/4257327799_28c2e74004_b.jpg

The lower chassis is a bit rusty.
http://farm5.static.flickr.com/4071/4257920913_0f216d1b4d_b.jpg

Made in good old Chicago
http://farm5.static.flickr.com/4034/4258059215_7dbeebcb30_b.jpg

I put some felt pads on the bottom so it's easier to slide around and protect my floors.
http://farm5.static.flickr.com/4071/4257921427_951cd89e1f_b.jpg

The 10BP4 tested nearly dead at first. I let it cook for a few hours at 7 volts and it improved until it was just touching the green. I may try rejuvinating once I get the set running.
http://farm5.static.flickr.com/4002/4257329361_59680ac67e.jpg

Here are a couple videos of me checking it out and trying to get it running.
The 1B3 appears to be bad and the 1/4 amp fuse was blown. I replaced the 6BG6, 1B3 and fuse and tried to power it up.
The fuse blew again. I need to do some more checking now. I sure hope the flyback is OK!

Any ideas?


Admiral 24A12 part 1 (http://www.youtube.com/watch?v=-JNx5BMVsyc)
Admiral 24A12 part 2 (http://www.youtube.com/watch?v=FzfVnheBkL0)

electronjohn
01-09-2010, 09:53 AM
Nice set, sir! I'm sure you'll have it playing fine in no time.

DaveWM
01-09-2010, 10:48 AM
I would check the grid of the HOT for bias, maybe a leaky coupling cap.

bandersen
01-11-2010, 03:30 AM
I would check the grid of the HOT for bias, maybe a leaky coupling cap.

Yep, the culprit was some bad caps around the HOT. Specifically, the multi-section electrolytic C422. I haven't replaced any of the other electrolytics yet or even touched the lower chassis, but I will. It's running pretty darn well right now and I can't wait to see how much better it might get with a full recap.

I also discovered several dubious repairs like these two 0.001 MFD caps in the sync inv. / disc. circuit. I have no idea what type of cap is correct or what the voltage rating should be.
I just went with what I had on hand - 630 V poly caps. Does anyone have a parts list for a 20A1 chassis that does specify these caps?
http://farm3.static.flickr.com/2739/4264939261_8fa96855ae_b.jpg


Also the original 8.2K power resistor in the HV cage is open and was bypassed at some point with the smaller green one. That's a shame because I really like that old style ceramic resistor.
I'll try to dig up one that looks better and mount it properly.
http://farm5.static.flickr.com/4050/4265688352_4381a8889f_b.jpg

There's an interesting metal hoop under the HV rectifier tube. I wonder what that's for?
http://farm5.static.flickr.com/4030/4265683078_bdedd44ab7_b.jpg

Here's the first picture I got using rabbit ears and local lower power channel 6 using a 5AXP4 test CRT.
http://farm3.static.flickr.com/2608/4264938303_577e0691de_b.jpg

And here it is using the 10BP4 :banana: The CRT is brighter than I was expected based on the weak test reading. I guess time will tell.
http://farm5.static.flickr.com/4025/4264938563_6b036f80d1_b.jpg

http://farm5.static.flickr.com/4054/4265688904_7dd4c9df92_b.jpg

http://farm5.static.flickr.com/4064/4265689116_5eaa0d5574_b.jpg

It's nice to have an easy restoration for a change :)

Sandy G
01-11-2010, 05:28 AM
I'm in love...An' in awe ! (grin) Those Bakelite Admirals are just SOOOOOO purdy...

Phil Nelson
01-11-2010, 12:50 PM
Gorgeous. I should look for an Admiral like that. Plenty of elbow room under the chassis, and a nice turret tuner.

Hard to believe you have such a nice picture with practically no work. I seem to end up with dogs of the other kind; weeks of slaving and scratching my head, and I finally get a picture looking that good . . . almost!

Phil

jr_tech
01-11-2010, 01:23 PM
Great find! it is nice to get an easy one once in a while!

"There's an interesting metal hoop under the HV rectifier tube. I wonder what that's for?"

If it is connected to the high voltage, I suspect that it serves as a (anti) Corona Ring, to reduce the possibility of corona and arcs between the sharp points under the tube socket (such as cut off wires and socket pins) and the chassis.

jr

bandersen
01-11-2010, 01:47 PM
Great find! it is nice to get an easy one once in a while!

"There's an interesting metal hoop under the HV rectifier tube. I wonder what that's for?"

If it is connected to the high voltage, I suspect that it serves as a (anti) Corona Ring, to reduce the possibility of corona and arcs between the sharp points under the tube socket (such as cut off wires and socket pins) and the chassis.

jr

That makers sense. Yes, it's connected to the HV - also the metal ring around the tube socket.

bandersen
01-11-2010, 01:52 PM
Gorgeous. I should look for an Admiral like that. Plenty of elbow room under the chassis, and a nice turret tuner.

Hard to believe you have such a nice picture with practically no work. I seem to end up with dogs of the other kind; weeks of slaving and scratching my head, and I finally get a picture looking that good . . . almost!

Phil

Thanks. I've found about 20 caps in this set that have 80s date codes. So I'm not the first to restore it. I'll probably end up replacing all of those though. Hard to believe the mid 80s was 25 years ago now!

Speaking of dogs, the previous owner had two dogs. So in addition to being stinky from cigarette smoke it's full of dog hair!

I bet I'll spend more time cleaning it than soldering :D

Reece
01-12-2010, 03:00 PM
Very nice pictures! Amazingly sharp. I noticed that set used a 6X5 in the power supply section. Those have been known to short and take out a power transformer. Here is a whole discussion about the early vs. the later version of the tube, the later "X" plate design usually deemed more rugged. One good idea is noted: provide a separate 6.3 volt transformer for the 6X5 heater, so that if it does short, it won't take out the power transformer. Some just replace the tube with a couple of diodes.

http://antiqueradios.com/forums/viewtopic.php?t=117188&highlight=6x5

bandersen
01-12-2010, 03:01 PM
I put up a couple more videos showing the first video images using the 5AXP4 and 10BP4.

Part 3: Recapping and using a 5AXP4 (http://www.youtube.com/watch?v=oV20h2h_2Sk)

Part 4: Using the 10BP4 (http://www.youtube.com/watch?v=FVscDj2iQJ0)

I've heard that the single 20X1 chassis from 1948 performs better, and am curious to put that to the test. Here's a portion of the schematic for one.

It doesn't use a sync. discriminator like this set from 1949 does. I would think using a discriminator is a superior design :scratch2:

http://farm5.static.flickr.com/4049/4269240649_c668471494_b.jpg

DaveWM
01-12-2010, 04:01 PM
wow that looks nice! great finding one that required so little to get going

wa2ise
01-12-2010, 04:12 PM
http://www.wa2ise.com/radios/admtvbb8.jpg

Mine (Model 24R12) actually worked before the recap. This back in 2000. Here it is above, after a recap anyway, with the game on. These sets seemed to have been well engineered and tough to kill. The weakest spot seemed to be the door that hides the controls between the channel and volume knobs.

bandersen
01-12-2010, 05:05 PM
Mine (Model 24R12) actually worked before the recap. This back in 2000. Here it is above, after a recap anyway, with the game on. These sets seemed to have been well engineered and tough to kill. The weakest spot seemed to be the door that hides the controls between teh channel and volume knobs.

Nice set :thmbsp:
A guy in Nebraska tried to talk me into buying that same model set and trust that it would survive shipping. I learned my lesson after destroying a similar bakelite set and turned him down.

I've heard that Admirals are hard to kill as well. Almost temps me to try powering up a couple I've haven't gotten around to yet :scratch2:

Yes, they almost always are missing that door. I only have one set that has it's original door and even that one is cracked :tears:

Dan Starnes
01-12-2010, 05:51 PM
That plays impressive for a CRT that was reading basically dead. Never thought about letting one cook like that,, Will try that in the future. Nice score!!

bandersen
01-13-2010, 04:53 AM
Very nice pictures! Amazingly sharp. I noticed that set used a 6X5 in the power supply section. Those have been known to short and take out a power transformer. Here is a whole discussion about the early vs. the later version of the tube, the later "X" plate design usually deemed more rugged. One good idea is noted: provide a separate 6.3 volt transformer for the 6X5 heater, so that if it does short, it won't take out the power transformer. Some just replace the tube with a couple of diodes.

http://antiqueradios.com/forums/viewtopic.php?t=117188&highlight=6x5


Thanks for the reminder. You guys warned me about that tube when I picked up my Halicrafters too.

I was flipping through the production changes and discovered that Admiral added a fuse on the power supply on later runs.
They also suggest that when servicing this set to retrofit a fuse in if it's not already there.

I think I may go the diode route since it's easily reversable :scratch2:

bandersen
01-13-2010, 02:57 PM
I dug a couple 6X5s out of my Admiral TVs. I wonder if this stacked design is any more reliable :scratch2:

http://www.bobandersen.com/images/misc/admiral6x5.jpg

bandersen
01-15-2010, 07:26 PM
I was surprised to discover that my 24C16 Admiral uses the same chassis!

http://farm4.static.flickr.com/3567/3615209151_0eba29b4dd.jpg

So, I order up parts for both sets and will recap them at the same time :yes:
The 24C16 is all original so I don't think I'd have the same luck if I tried powering it up :no:

I have both the lower chassis up on the workbench and am stripping the rust and rebuilding them. Normally, I woudln;t go to these lengths, but these are really easy to take apart and reassemble.
I did find a couple fired wax caps on the amp down there so I bet this set will sound even better after the recap.
I've already repainted the transformer and polished the tube shields over on the left.
http://farm3.static.flickr.com/2684/4277192469_0024966434_b.jpg

The caps I have on hand are a little too big to fit in the old cans. I did a little searching and found a line of skinny caps at Mouser that will with room to spare :)
I got a nice pile of orange drops too :D
http://farm5.static.flickr.com/4035/4277939058_394bdfc91c_b.jpg

Reece
01-16-2010, 06:14 PM
If you go the diode route, you can leave the 6X5 in its socket "for pretty" and just disconnect the socket. The power xfrmr will have a little better time of it with one fewer heater to heat.

bandersen
01-17-2010, 09:52 PM
If you go the diode route, you can leave the 6X5 in its socket "for pretty" and just disconnect the socket. The power xfrmr will have a little better time of it with one fewer heater to heat.

Good idea. Perhaps I should do that for the 5U4 tube as well.

If I'm reading the tube data right, it looks like there's a 25 volt drop for every 100mA drawn. That means I should use a 250 ohm resistor in series with the diodes I think :scratch2:

bandersen
01-23-2010, 12:09 AM
I've finish restoring the lower power supply + audio amp chassis. Here it is with an unrestored chassis from another set in the background.
I removed the rust from the chassis, choke and audio xfrmrs and buffed them with a non-metallic pad and WD-40. I stripped the power transformer shell and repainted it with black enamel paint. The electrolytics were restuffed and the caps below replaced. A couple out of spec resistors were replaced too.
http://farm3.static.flickr.com/2739/4297183810_266f63119c_b.jpg

I'm just about done recapping and replacing out of spec resistors in the top chassis too. Only a few old replacements I left in place because they tested OK.
http://farm5.static.flickr.com/4065/4296437391_5b9d07485a_b.jpg

Here's the new power resistor in the HV cage. It's a little shorter than the original so I used a wooden spacer.
http://farm5.static.flickr.com/4060/4297184220_fc65acf0b1_b.jpg

Only one issue remains.
If I tune for the best picture, the audio is very weak. If I tune for the best sound, I have a lousy picture.
I haven't touched the RF/IF states yet. Maybe it's just a weak tube or a bias resistor is off ?

Otherwise, it's playing just fine. BTW Those earlier pictures look sharper because they were still frames - this is live motion.
http://farm5.static.flickr.com/4034/4297184896_b2fde4cd22_b.jpg

jeyurkon
01-23-2010, 12:32 AM
That power supply looks amazing! John

zenithfan1
01-23-2010, 12:36 AM
Another perfect job! That power supply looks better than new.

bandersen
01-23-2010, 01:11 AM
Thank guys. If you're wondering about that one black screw head - well I think those engineers meant for it to not come out. The screw head was pinched. Probably to prevent someone like me from loosening the core up to much and having all the laminated plates come apart :)

Any ideas about the video and audio being out of whack? Several other sets seem to suffer from the same problem. Maybe it an alignment issue or maybe my converter box is driving it too hard? I'll try my BT agile modulator tomorrow.

jeyurkon
01-23-2010, 01:24 AM
Thank guys. If you're wondering about that one black screw head - well I think those engineers meant for it to not come out. The screw head was pinched. Probably to prevent someone like me from loosening the core up to much and having all the laminated plates come apart :)

Any ideas about the video and audio being out of whack? Several other sets seem to suffer from the same problem. Maybe it an alignment issue or maybe my converter box is driving it to hard? I'll try my BT agile modulator tomorrow.

Hopefully it's the converter box. The RF from mine is horrible. It even acts that way with a modern TV. Using a BT modulator makes a world of difference for me.

Otherwise it could be an alignment issue. Though it seems like that's not too common. I was surprised that after having to rewind a video IF transformer in my set that I didn't have to align it. It seems to work at the quessed position of the core. I expected it to be more critical than that.

John

Reece
01-23-2010, 01:45 PM
Nice job on that power supply.

bandersen
01-26-2010, 02:41 AM
A guy in Nebraska tried to talk me into buying that same model set and trust that it would survive shipping. I learned my lesson after destroying a similar bakelite set and turned him down...

Gee what a surprise!
Here's that very set he tried to convince me would survive shipping just fine. It was destroyed in shipping and now he's selling the remains.
I told him not to try it :no: :tears:

http://cgi.ebay.com/Bakelite-Admiral-TV-1940-50s-24a12-tube-cover-speaker_W0QQitemZ250567121991

bgadow
01-26-2010, 11:44 AM
And after all that, I see he still has UPS listed as the shipping option. No thanks!

I'll ship a small portable, but that is all. I've hardly ever heard of something like this working out well.

jr_tech
01-26-2010, 01:49 PM
I'll ship a small portable, but that is all. I've hardly ever heard of something like this working out well.

Even that does not assure safe delivery... This little (12-13lb) Sony KV-5000 arrived at my house yesterday, with a broken handle, a cracked circuit board around the power plug, and the yoke shoved way back (which makes for a small "roundie" picture and rainbow effect). With a little glue, solder and adjustment, the set is pretty much ok, with a little purity issue near the right side.

So far, I have had good luck with Sony Watchmans, and nothing larger.

jr

Dan Starnes
01-26-2010, 02:08 PM
First rate work and thanks for the great pics, very interesting.

wa2ise
01-26-2010, 09:08 PM
Gee what a surprise!
... It was destroyed in shipping and now he's selling the remains.
I told him not to try it :no: :tears:

I got mine about 12 years ago, and my dim memory says it was shipped by a trucking company, and well wrapped in bubble pack and corrugated cardboard box. With the chassis packed separately. It arrived in fine shape. And so far movers haven't fumbled it, after a few moves.
http://www.wa2ise.com/radios/admtvbbf.jpg

I could use the back, and a new clear faceplate (mine has a scratch). But I don't have enough room to keep the extra chassis, and $50 + $75 shipping is a bit pricey.

bandersen
01-26-2010, 09:19 PM
I got mine about 12 years ago, and my dim memory says it was shipped by a trucking company, and well wrapped in bubble pack and corrugated cardboard box. With the chassis packed separately. It arrived in fine shape. And so far movers haven't fumbled it, after a few moves.

I could use the back, and a new clear faceplate (mine has a scratch). But I don't have enough room to keep the extra chassis, and $50 + $75 shipping is a bit pricey.

Hopefully he'll keep dropping that price. Or maybe you can ask him to sell just the parts you need ?

I did have one set shipped successfully and I did the same - cabinet and chassis in separate boxes well packed. Even so, I'd be leery of trying it again.

One of these days I'm going to move to a bigger place and it just so happens the collector I bought this set from owns a moving company :)
I'll feel better with my sets in his hands than some random outfit from the phone book.

bandersen
01-26-2010, 10:21 PM
First rate work and thanks for the great pics, very interesting.

Thanks - glad you're enjoying it. I have about 20 more sets to restore so lots more to come in 2010. Here's a few more about this set.


I was lucky to get a back with this set. It's a little bent and rusty, and someone cut a slot for the optional internal antenna.
I don't have that antenna though - wonder what happened to it.
http://farm3.static.flickr.com/2752/4307663583_67fb448565.jpg


That's the optional internal antenna in the background from another set. Next is the back from my 20X122 with the factory cut slot. Finally, is the back that came with this set.
http://farm5.static.flickr.com/4060/4308403408_7ff78c7a36_b.jpg


This set didn't come with the antenna, but I have one from another set. It was only commended for those in a strong signal area. Translation - it didn't work very well ;)
http://farm3.static.flickr.com/2750/4307664189_c4ee4d13b3_b.jpg

http://farm5.static.flickr.com/4039/4307695859_8db8777f0d_b.jpg

I was digging through my tubes and came across these two guys - solid state replacements for a 5U4. I don't know if I'll bother trying them though. Is 30 year old silicon any more reliable than a 60 year old tube :scratch2:
http://farm5.static.flickr.com/4038/4307663885_97d5c97993.jpg

wa2ise
01-27-2010, 01:52 AM
Come to think about it, but I wonder how Admiral got those Bakelite TV sets from their factory to the TV shops and to customers' homes? :scratch2:

bandersen
01-27-2010, 04:55 AM
Dunno, but the ETF has a great photo showing how strong they supposedly were.


http://www.earlytelevision.org/images/pop_sci_9-49-1.jpg (http://www.earlytelevision.org/admiral_19a11.html)

http://www.earlytelevision.org/admiral_19a11.html

bandersen
02-05-2010, 10:08 PM
While re-installing the chassis I notices they had been rubber mounted. My wooden cabinet Admirals are not. I'm guessing it's because bakelite is more dense :scratch2:

They're not in the greatest shape so I've been working on replacing them. I used some plumbing washers for the lower chassis.
http://farm3.static.flickr.com/2730/4333371041_1a0004351d_b.jpg

I'm going to try to salvage the upper chassis mounts with some metal -> rubber cement.
http://farm3.static.flickr.com/2773/4333372227_a4fa2358a8_b.jpg

http://farm3.static.flickr.com/2762/4333371577_53c14aa329_b.jpg

bandersen
02-05-2010, 10:17 PM
Although this CRT is working OK now, I doubt it will for long. So I've been keeping my eyes open for a replacement. I was quite surprised to see a NOS 10FP4 on eBay last week. I really hope I wasn't bidding against one of you guys :para:

Here's it is in it's original box.
http://farm3.static.flickr.com/2770/4333368919_5233cc668e_b.jpg

Did GE have exclusive rights to this tube ?
http://farm5.static.flickr.com/4046/4333370073_fa56bef908.jpg

http://farm3.static.flickr.com/2719/4333369531_1a350d7677_b.jpg

It tests really good :thmbsp:
http://farm5.static.flickr.com/4029/4333370593_595fd71ce6_b.jpg


Here are a couple pics from my initial tests. It's hard to photograph the difference but to my eyes this tube is brighter and clearer.
Maybe it's not kosher to use a 10FP4 in this set but I'm not complaining.
http://farm5.static.flickr.com/4070/4334116002_b1ff85c75e_b.jpg

http://farm3.static.flickr.com/2780/4334116534_cefabd8000_b.jpg

Here's a video I shot while trying out this CRT. http://www.youtube.com/watch?v=ua47ZsW9L4s

Glenn Waters
02-18-2010, 04:37 PM
Very awesome restoration!
Here is Cora's latest find, She rescued this pretty Admiral from the Fairview, trash compactor. She took it apart and after a good cleaning and a few new tubes she is as good as new. The paint is still show room new. She does get hot after a hour or so, so we only play her for short periods. I do not think she was ever watched at all from the condition she was in.
http://img6.imageshack.us/img6/1900/admirall.jpg

bandersen
02-18-2010, 09:38 PM
Thanks. I got a new antenna a few days ago. Now it's the spitting image of Eric's (http://www.vintagetvsets.com/24a12.htm) :D

http://farm3.static.flickr.com/2778/4366851601_33cff1414a.jpg

bandersen
04-28-2010, 10:35 PM
I've been using a Simichrome a lot lately on brass and cadmium. It's been working so well I ordered up a big can of the stuff.
Then I got to thinking, how would it work on bakelite :scratch2:

I had previously used a little Novus #2 and Glayzit on the top. Here's what that looked like.
http://farm4.static.flickr.com/3552/4561721553_924f8bfde1_b.jpg

Here it is after a little Simichrome. I've only done the top, front edge and around the screen so far.
http://farm4.static.flickr.com/3411/4562351184_363dba0cbd_b.jpg

Here it is after a couple more rounds of polishing.
http://farm4.static.flickr.com/3142/4564280634_78bde0e6a9_b.jpg

http://farm5.static.flickr.com/4016/4561721709_af942782b8.jpg
I won't kid you, it takes a lot of elbow grease. I spent about two hours on the Admiral and my arm is shot. Doing the sides and grill will take even more effort, but I think the results are worth it.

bandersen
01-28-2011, 10:40 PM
The Nixer posted this comment on my Flickr page and I thought I'd share it here.
It's been years since I saw this movie and certainly didn't notice the Admiral at the time. Very cool to see one in action in a movie I think.

You may have already seen this but I was watching La Bamba last night and was extremely happy to see an Admiral bakelite console in Ritchie's Mom's house.

The TV would be about 10 years old in the movie. There were also some other neat TV's. Bottom right looks like a Motorola console and bottom left looks like a neat looking portable Zenith. I freaked when I saw the Admiral though. I'd love to know if it appears in any other movies.

You can see the clip here (http://www.youtube.com/watch?v=xhRpOUj-JHg&feature=related), it's at the 6:29 mark. You see all the TV's within a matter of moments.

bandersen
04-10-2011, 10:43 PM
I recently pulled this set out for a little tuneup and thought I'd update this thread.

First off, that rubber to metal cement really did the trick. All four mounts are very securely attached now.
http://farm6.static.flickr.com/5028/5604828219_5b74c49d84_z.jpg

Next up, I removed the rust from the back, polished it up and clear coated it.
http://farm5.static.flickr.com/4111/5605411654_4a763c2f2c_z.jpg http://farm5.static.flickr.com/4095/5604846457_39ef6238bd_z.jpg

Then, I polished up the faceplate with Novus 1 & 2. I also attached a new foam surround with a little contact cement. I used it sparingly and had no problems with it attacking the old plastic.
http://farm5.static.flickr.com/4096/5605429932_7f1fb68d1b_z.jpg

I also finally got around to cleaning up all the grillework. That grille cloth has really faded.
It looks like the original color was green ?
http://farm6.static.flickr.com/5145/5605430100_bf583f23a0_z.jpg http://farm6.static.flickr.com/5143/5605430670_3a37433710_z.jpg

Here it is all back together.
Ihttp://farm6.static.flickr.com/5262/5604888225_5ae905c19e_z.jpg

bandersen
04-10-2011, 10:54 PM
While I had the chassis out, I also replaced most of the tubes in the tuner and IF and did a full alignment. It made a big difference in the picture quality.
http://farm6.static.flickr.com/5186/5559690601_194a9d3e4e.jpg http://farm6.static.flickr.com/5139/5563880342_7297bb7989.jpg

Here's a multi-burst test pattern. The bands on the far right are 4.2 MHZ and just barely discernible. The B&K 1077B test pattern looks pretty good too :)
http://farm6.static.flickr.com/5185/5605411002_a1f8622256.jpg http://farm6.static.flickr.com/5147/5605411160_8afbb09a16.jpg http://farm6.static.flickr.com/5187/5604827661_c3ebac92da.jpg

There's just one problem. Now, I'm seeing what i believe are called 'chroma dots'. I recall reading a tip about using the green component output of a DVD player fed into an RF modulator. I tried that and it definitely did the trick.

Does anyone know any other tricks to reduce or eliminate them ?
http://farm6.static.flickr.com/5270/5608269695_e1e8cd4001.jpg

miniman82
04-10-2011, 11:37 PM
If you have a DVD player that has component output, hook the Y line into the set right after the detector. You won't believe the difference!

Barring that (you don't get sound unless you hack the audio section as well), you'll need to filter out the 3.58 info to get rid of the dots. It's really bad on a Philco-Ford set I just got (which is color but still suffers), the dot crawl is atrocious. I don't think it properly filters out all the info for the chroma section, there's obviously still 3.58 in the luma. Some kind of tuned trap is what you'd need, good luck with that.

I've been toying with the idea of feeding the Y and audio lines right into my Magnavox modulator, and feeding the TV with that on channel 3. Maybe you can do something similar?

bandersen
04-11-2011, 12:16 AM
If you have a DVD player that has component output, hook the Y line into the set right after the detector. You won't believe the difference!

Barring that (you don't get sound unless you hack the audio section as well), you'll need to filter out the 3.58 info to get rid of the dots. It's really bad on a Philco-Ford set I just got (which is color but still suffers), the dot crawl is atrocious. I don't think it properly filters out all the info for the chroma section, there's obviously still 3.58 in the luma. Some kind of tuned trap is what you'd need, good luck with that.

I've been toying with the idea of feeding the Y and audio lines right into my Magnavox modulator, and feeding the TV with that on channel 3. Maybe you can do something similar?

It tried the green component output of my DVD player into an RF modulator and it works quite well.
Too bad my DTV receivers only has RF and composite output. My cheapo Comcast box is even worse - it only has RF output. I generally use a Blonder Tongue agile modulator to broadcast to my sets and they only take composite video.
I suppose I could try a 3.58 MHz notch filter like this: http://www.allenavionics.com/LC_F/NTSC.htm

charokeeroad
04-11-2011, 10:18 AM
Watched all eight videos on the restoration of this set. I learned a lot but still don't feel ready to do a restoration yet. For the time being I'm just collecting as many interesting sets as I have room for.

Kevin Kuehn
04-11-2011, 11:51 AM
Viry nice work, I wish I had half your ambition.

It looks like those chroma dots are not really visible from a normal viewing distance? That set now has an incredibly sharp picture. Maybe you've gone and done "too good" of an alignment. In other words you could mess it up a little. :D

Kevin

wa2ise
04-11-2011, 12:13 PM
There's just one problem. Now, I'm seeing what i believe are called 'chroma dots'. I recall reading a tip about using the green component output of a DVD player fed into an RF modulator. I tried that and it definitely did the trick.

Does anyone know any other tricks to reduce or eliminate them ?
http://farm6.static.flickr.com/5270/5608269695_e1e8cd4001.jpg

I modified my Channel master CM7000 box to only feed the luma and not chroma to its RF modulator.
http://www.videokarma.org/attachment.php?attachmentid=167112&d=1273091337
http://www.videokarma.org/attachment.php?attachmentid=167111&d=1273091337
This box uses a special group delay filter on the video signal to condition it for TV set reception, just like real TV stations did back in the old analog NTSC days. Si it should produce really good pictures on your set, it does on mine.

bandersen
04-11-2011, 12:34 PM
Viry nice work, I wish I had half your ambition.

It looks like those chroma dots are not really visible from a normal viewing distance? That set now has an incredibly sharp picture. Maybe you've gone and done "too good" of an alignment. In other words you could mess it up a little. :D

Kevin

Thanks. No, it's not really visible at normal distance. Making the focus a little fuzzy helps too. It also blends the horizontal scan lines and makes a more natural looking picture.


I modified my Channel master CM7000 box to only feed the luma and not chroma to its RF modulator.
...
This box uses a special group delay filter on the video signal to condition it for TV set reception, just like real TV stations did back in the old analog NTSC days. Si it should produce really good pictures on your set, it does on mine.

Cool. If I can get my hands on this model, I'll give it a try.

old_tv_nut
04-11-2011, 12:47 PM
you'll need to filter out the 3.58 info to get rid of the dots. It's really bad on a Philco-Ford set I just got (which is color but still suffers), the dot crawl is atrocious. I don't think it properly filters out all the info for the chroma section, there's obviously still 3.58 in the luma.

There should be an adjustable (tuned coil) 3.58 trap somewhere in that set. (The CTC-5 Super chassis didn't need one because the luma response was so strongly rolled off already.) Excess 3.58 dots desaturate the color, so you do need to fix that for best picture.