...

This is truly impressive. I'm following this thread with great anticipation :)

Thanks!

I have kept the images small because of the sheer number being posted, as I don't want to overrun my storage quota here at VK. If anyone wants to see the full resolution copy of any of these pics, just send me a PM.

The installation of chassis components went pretty smoothly, with the only solderability issues being a few of the diode leads, which needed a good cleaning to remove the silver plating tarnish. The components form the final "layer" of the chassis wiring, and complete the work on the backside of the chassis.

More pics attached.

Next up: Finishing the chassis topside wiring, and module installation.

Yes, the suspense is building! Let's hope the remainder of the project goes smoothly.

I was thinking that this must be one of the most complicated kits ever offered to consumers. Color TVs have an awful lot of parts & pieces.

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

I was wondering about the "most complicated kit" title. This is certainly the most complicated Heathkit I have had the fun of putting together, with the second being a "Hero Jr." robot.. I think the later GR-2000 and GR-2001 sets with the on screen display beat this one by a bit, with the addition of several digital boards for the advanced features.

The other contenders for the complexity prize would possibly be the Heath/Thomas electronic organs, or possibly the H1 Analog Computer:

http://www.technikum29.de/en/computer/analog

The chassis assembly is completed with a handful of electrical connections on the top side of the chassis, to the IF module and power supply filter choke.

The 9 previously completed PCB modules are then installed into their proper locations, and the chassis set aside for final assembly with the rest of the set. These pics are of the top side of the completed chassis, with all modules installed.

Up next, assembling the VHF/UHF tuner cluster and control panel...

:rockon:Wow!

Interesting that it uses a HV rect tube.

Probably has to do with the year it was first available-1969. I don't think there was a reliable solid-state substitute yet.

In 1974 I went to work for Varo Inc. and among the things they manufactured were solid-state high voltage rectifiers and triplers for TVs. By then they were reliable and common.

Varo pretty much owned the market on those things, didn't they? I think they were the first to produce them. I agree the 1969 introduction of this model would have been just a bit early for SS. I assume the GR2000 series sets used a solid state HV rect or tripler?

I have an ECG solid state replacement here which I think would work in this set should the 3CU3 ever give problems.

Onto the next assembly manual, covering the assembly of the Tuner cluster/Control panel. The manual is divided into 2 sections, and the builder follows the half with or without the remote control option as applicable.

Work starts out as more mechanical assembly. The VHF and UHF tuners come preassembled, and are mounted into a metal subchassis. The tuner drive motor and gearbox get attached, along with numerous terminal strips and a large oil filled capacitor (4 uF, 370V) used for reversing the tuner drive motor. The supplied capacitor was a Sprague "Chlorinol" capacitor, which was a trademark for polychlorinated biphenyl, or PCB. :thumbsdn: Although the cap looked pristine with no signs of leakage, I replaced it with a modern non-PCB cap to remove the environmental hazard. The new cap fits the original mounting perfectly and looks original to the set. The original cap is safely stored away for the next hazmat collection day.

All the pots get attached to a bracket, which is then mated to the front subpanel and the tuner chassis, completing the mechanical assembly. Because I am installing the remote option, drive motors get installed onto the back side of the color and tint pots to allow remote operation. The UHF and VHF channel indicator dials are backlighted by incandescent lamps, and driven via a small timing belt drive. The VHF fine tuning is driven with a ballchain drive system. 4 pushbutton switches are installed for power, channel up/down, and UHF/VHF select.

The wiring is almost completely prefabricated harnesses, which are quite long and make for a real pain on the bench. The unit ends up with quite a wad of wiring attached.

The final part of the assembly is the stuffing of a small PC board which they call the "UHF" board, but what it really handles is the switching between UHF and VHF tuners, and driving the appropriate dial backlight for the selected band. The board is connected to the chassis via a 15 pin Molex connector which supports the entire board. While Heath sent a 15 pin Molex connector which I dutifully installed, It wasn't until trying to plug the board in that I discovered that the WRONG GENDER of connector shell was supplied! Luckily, I had a proper connector shell, as well as the pin extraction tool to remove the contacts from the supplied shell, and reinsert them into the proper one. The board survived the desoldering and resoldering just fine, and the tuner cluster was completed in 3 bench sessions totaling around 5 hours.

More pics.

Up next--Installing the CRT and bringing all the parts together for final assembly!

Onto book #4, covering assembly of the CRT, mask, and chassis frame.

I began the process by building a temporary "T" extension (3/4" plywood and 2x4 legs) onto my workbench to provide enough room to work on the assembled set. Most of the projects I tackle in my shop are a good bit smaller than this beast! :yikes:

First up, I decided to actually test the CRT to make sure it was still electrically good. The CRT carton was pretty well destroyed by moisture, and the tube itself has a nasty cataract extending 3-4 inches in toward the center in a few spots. Assuming the set makes a good picture, a cataract removal or (preferably) a CRT replacement can be pursued later. The supplied tube is an RCA 25VABP22, but the manual refers to a 25VADP22. Comparing datasheets shows the tubes are pretty much identical, with the later VADP having a "Temperature Compensated" (Invar?) shadow mask for improved purity. I seem to remember that most of the 25V-series tubes were fairly interchangeable, with minor differences like black matrix, rare earth, mounting ears, etc.

Firing up the tester, the tube was a bit slow to warm up after sleeping all these years, but after a few minutes warmup the guns balanced perfectly, with emission and life test readings consistent with a NOS tube. :smoke:

Assembly begins by placing the plastic CRT mask face down on supports (4 blocks of 2x4), and lining the inside of the mask surface (where the edges of the CRT faceplate rest) with aluminum foil tape as an electrostatic drain. The provided roll of 3M foil tape was still perfectly usable after 4 decades in storage. The foil is carefully overlapped in the corners, and folded over to make contact with the CRT mounting hardware.

The CRT is then placed into the mask opening, making sure that the anode contact faces the top edge of the mask.

The CRT clamps and straps are prepared by adding adhesive felt pads (also amazingly viable despite age) and rubber cushions at the points where the clamps bear against the glass. the clamps are carefully drawn down tight in several stages until they bottom against the mask, then the strap screws are tightened to clamp the tube into place.

A long length of bare solid wire and a coil spring are installed as a grounding contact for the outside dag coating, and the degaussing coil is wrapped around the tube in a very carefully specified pattern (to assure even magnetic field over the mask area), and anchored in place with cable ties.

Next up--final chassis assembly and moving toward "First Light"....

I can't wait to see this up and running! Great job!

Very interesting thread!

Though, sorry but that remote is ugly as sin! Even for an old ultrasonic remote that thing is just ugly!

Great work no question. It's always a pleasure to build a device with your own hands. I built a few custom devices at work and know how much time it takes because I had to drill every hole and crimp every connector by hand. Did you clean the pcbs with spiritus after soldering and count the hour´s it takes? Greetings and good luck!

Yes, the remote is pretty fugly. The "thousand island dressing" color scheme doesn't help...:scratch2:

I did clean the modules with flux remover after soldering. I haven't been keeping all that close a count of hours, but 40-45 hours to this point is my best guesstimate, not including the time inventorying the parts, ordering replacements, and related activities.


After installing the CRT into the mask, the 4 sides of the chassis frame/magnetic shield are attached to the mask and bolted together forming a rigid box structure. The dag ground from the CRT assembly is grounded to this frame. The deflection yoke is installed into the "flowerpot" style holder, and installed onto the CRT neck. The completed chassis is hung on its hinges, and the degaussing leads and CRT anode wire are connected, before closing the chassis. I elected to replace the somewhat stiff and degraded anode cap with a nice silicone rubber one salvaged from a discarded BPC set.

After the chassis is installed, the entire framework and tube was thoroughly degaussed (using a real coil, not the dinky external one provided with the kit), and the convergence magnets/coils and blue lateral/purity magnets were installed, along with the CRT socket. The convergence board, tuner cluster, and "Troubleshooter" meter are hung on screws in the framework for the initial test/adjustment procedures, and all the interconnecting cables plugged in.

This completes the assembly of the set! Up next, using the "Troubleshooter" to check for problems, and power gets applied for the first time....

Light that sukka!!! :D

SR

Testing begins with a series of testing flowcharts, where the builder uses the provided VOM to make a series of resistance tests to verify that no major shorts or miswiring exists. Tests were made using both the "Troubleshooter" VOM and a DMM (Fluke 87). As Heath gave no specific resistance values, just which area (A-E) the troubleshooter needle should indicate for each test, I noted the actual resistance reading taken with the DMM in my build notes.

You test the AC line circuitry first, checking for continuity and shorts to chassis ground. Then the various main power supply rails are checked for resistance to ground, to rule out shorts or reversed polarity components that might cause damage at powerup. About a dozen tests all together, and all passed with flying colors. :thmbsp:

At this point, you preset the brightness, brightness limiter, drive, screen and kine bias controls as specified, and unplug the CRT socket. The set gets connected to 120 vac, and the switch is thrown.....


No bang....:yes:

The gentle crackling sound of HV supply coming alive! :banana:

No smoke or bad smells...:yes:


Back to the testing charts, where measurements are made of cathode, G1 and G2 voltages, and a couple power supply rails. All well within the specs...:D

An occasional snap/crackle was noted from inside the HV cage and traced to a bit of cardboard packing material that was trapped under the edge of the HV rectifier tube socket. :sigh:

The set is then powered down, and the CRT socket connected. Ready for "first light" tomorrow night, when my chroma board helper and her mom are dropping by for dinner and to watch this thing come to life. The suspense is killing me...:eek:

Not much in the way of pics for this post. I hope some screen shots will be taken tomorrow night....:smoke:

Power applied.

Heaters start warming up, and....

It Lives!!!

First light: June 17, 2016.

After a couple minutes of snapping pictures and sniffing for smoke, I flipped on the built in dot generator and got pretty much what I expected. Could have been cover art for a 60's psychedelic band. Convergence just about as far out as it is possible to be in every direction. Horrible purity, and overall reddish cast with blurry retrace lines, but it makes an image! My visitors seemed puzzled why I was as happy as I was with what we saw. Had to explain the large amount of adjustment and tweaking that needs to be done to a set of this vintage to get everything just right. And that having a picture even this good means that 90% or more of the set is already working properly.

A quick purity setup, static convergence setup and greyscale adjustment produced a nice stable black and white image. A few tweaks of the 3.58 osc and burst phase got a reasonable color image, and tweaking the AGC got it fairly viewable in about 20 minutes.

Today I went through and finessed things in a bit better, and got things as good as the "non instrument" alignment procedure is going to, I think. I plan to follow the full alignment procedure detailed in the final volume of the manual set, and at least verifying that the IF and chroma circuits are lined up. Several coils and traps are left unadjusted when using the simplified procedures, and I think I can squeeze a bit better image out of this thing with a real instrument alignment. Both the color and tint controls have a very limited range of action, right around the center of travel. Color level particularly touchy to set to get reasonable skintones without over or saturation.

It's been a month and a half since I started this journey, and had a great time doing it! Will begin looking for a suitable NOS replacement tube and designing some kind of cabinet for this beast. Any leads or ideas gratefully accepted...

Couple more pics...

That thing looks awesome! Almost like a brand new set:thmbsp::smoke:

Over the last week or so, I have managed to track down a potential source for a replacement tube, and should have it in the next few days. New tube is a 25VCZP22, which appears to be a tension banded successor to the bonded faceplate VAB/VAD types. Hoping it fits the mask on my set OK. Datasheet comparison looks promising.

Spent an hour or so setting up the UHF tuning presets. To use all 12 presets, I selected all the now defunct local UHF stations I can remember, and added a handful of others. 14 and 83 just to cover the entire band for testing purposes, 37 just in case I want to listen for aliens, and channel 62 to tune in the occasional Blonder/Tongue modulator broadcast of "UHF". :D Dialed all channels in using a VA62. All the channel number stickers were in great shape, and applied to the UHF channel display wheel.

Varactor UHF tuner works VERY nicely, good stable reception on all channels. Did any commercial sets have varactor UHF tuning in 1969?

Am pondering how best to add a composite AV input to this set. Video amplitude out of the detector measures about 2Vpp, but proper polarity. Applying a proper level video signal from the VA62 right into the video cable to the IF module gives a GREAT picture. I need to design a video amplifier with a gain of ~2, preferably to operate from the single ended 30V power supply available in the set. Shouldn't be too big a deal using a modern video opamp. Line level audio input will probably be done by just rewiring the provided "HiFi out" line level audio output jack to be a line level input to the top end of the volume pot.

The set has an unused position between 2 and 13 on the VHF tuning dial (where UHF would be on a non varactor setup) which displays "H" (for Heathkit I guess:scratch2:) on both UHF and VHF tuning dials. I am contemplating rigging up a switch/relay to automatically select the AV input in this tuner position, so as not to have to add a separate line/RF switch.

Dynamic convergence has drifted a tiny bit in the last week or so (maybe 8 hours run time). Nudged it back, but obviously going to be redone again at CRT swap.

Contemplating a cabinet design to be a winter project. Thinking wooden front and bottom, with transparent top, sides, and back.

I've wanted to ad a composite video input to my GR-900 also. I found a circuit from an Early Television Foundation presentation from some years back. I built it but it wasn't flat out to 4.5 MHz so I abandoned the idea.

How about injecting it right after the diode and before the final IF stage? Haven't tried that yet as it is in a sealed can.

...

I have serious doubts about the safety of tubes that have undergone the standard cat removal procedure. The whole purpose of that resin was to effectively form a glass/resin/glass laminated panel, similar to automotive safety glass. Without the resin layer, it is just an unprotected CRT behind a second sheet of non-safety glass (the reinstalled faceplate). At least the older sets actually used a laminated glass safety panel in front of the unprotected CRT. The faceplates on laminated tubes are just tinted or frosted glass, which would only add to the shrapnel from an implosion if not bonded with the resin.

Obviously CRT rebuilders must have had a way to remove and rebond these faceplates properly when rebuilding tubes, as the resin would never have stood up to oven bakeout. Does anyone know how this was done? It isn't addressed in the excellent film made of HawkEye's rebuilding process over on the ETF site. I imagine that it takes some special setup (like vacuum impregnation) to ensure no trapped air bubbles in the resin. Clear 2 part urethane casting resin is available from several suppliers, and would probably be a good substitute for the PVA that was originally used, if a way was available to get a void-free fill.

The 25VCZP22 that I found locally turns out to have issues with the red gun, so probably won't be used. The ETF has a pair of NOS 25VABs available for $75 each, so if one of them is cat-free I will likely purchase one of those. They are in the process of checking them for me. The VCZ would have actually been a nicer tube, being a tension banded type with no cataract worries at all. Bummer about the red gun...

The new tube arrived yesterday, and looks like a beauty. A Sylvania "AA" grade, all new "Chromatrix" tube. Completely cataract-free, and with a date code of "2013" which I am guessing is a code of some kind, not a 3 year old tube. Box looks a good deal older than that. :D Even got the warranty registration card (should send it in for a laugh!):yes: Thanks to Steve at the ETF, and a friend of mine who was able to bring the tube from Ohio back to NJ for me, saving $$$ on shipping

Tube tests perfectly on the CR-31A, and will be installed after I return from a week's vacation.

In this post, I described a process that I have observed:

http://www.videokarma.org/showpost.p...11&postcount=2

jr

Interesting. Thanks for posting that. The PPG number you posted appears to be an automotive paint, not a bonding resin. I have used various products from Forsch Polymer Corp. over the years, and they have a few resin systems that seem like they would work well for this application, with low uncured viscosity and good transparency when cured.

May have to give it a try on a dud tube at some point to see if the cataract problem can be solved without compromising future safety.

I tried to dredge another number out of the old memory cells, but I keep comming back to PPG 5252. Dead cells? Two numbers associated with this task had a nice rhythm, like 5252 and 1418 for the UL crt implosion test document. Wonder if the 5252 number got recycled to another product after the process was retired. :scratch2:

The resin that was used was heated (85 C ?) in small batches and the mek-p catalyst was added and mixed in just before the pour was made. When cured, the resin had a rubbery consistency.

Good luck with your experiments,
jr