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-   -   Sooo. a Hallicrafters 815 followed me home... (http://www.videokarma.org/showthread.php?t=269046)

VintagePC 05-21-2017 02:47 PM

Sooo. a Hallicrafters 815 followed me home...
 
Argh... the sickness... it's getting worse :P
(Since I've last been around here I sadly had to sell my Fleetwood console TV; it was simply too large and bulky to take with me :tears: ... I guess this is an attempt to fill the hole in my heart? :D)

This followed me home for a song and a taxi ride (because there was no way I was gonna carry that to and from relevant public transit) No power cord, which means nobody's plugged it in to try it out. Cabinet is pretty beat up, but inside looks to be in pretty good shape and had an easy life. All the tubes are there, no melted flyback or scorch marks on the underside of the chassis, and no critters have made it a home. Minor chassis corrosion, and I don't see any signs of large-scale butchery on the circuitry.

Step 1... Get some service info. Any leads? Looks to be a Hallicrafters 815-A5. Quick google points to a SAMs and not much else, but I will admit it was cursory and not in depth yet.

Initial pictures - note the revision stamps on the tube chart where they've opted to make the whole set a 6v one...

http://vintagepc.forceanature.com/site/hctv/hc.jpeg
http://vintagepc.forceanature.com/si...m_IMG_0009.JPG
http://vintagepc.forceanature.com/si...m_IMG_0010.JPG
http://vintagepc.forceanature.com/si...m_IMG_0011.JPG

Olorin67 05-21-2017 04:17 PM

looks like the set I had, i sold it a couple years ago to someone from Chicago. i got it for free about 1989 at an estate sale.

VintagePC 05-21-2017 05:52 PM

Looks like the service info is either Riders 7-1 or Sams 124-6. Anyone have a scan or will I have to cough up some cash? :)

EdKozk2 05-21-2017 08:07 PM

I looked up your set in Sam's 124-6. The Sams schematic shows a 16GP4 round crt. What's in your set? There seem to be a few production changes too.

EdKozk2 05-21-2017 08:24 PM

Did some more checking, the Riders' 7-1 schematic shows a 16RP4 crt for the 815. Looks like Sams tried to cover eight chassis in one schematic. Some had an AM radio in a console version.

VintagePC 05-21-2017 08:40 PM

Thanks for checking, mine's got a 16RP4

Probably a common chassis, there's provision for a phono input in this even though it's a tabletop doghouse (including populated and labeled front switch, not just a "hidden" thing that got left in)

EdKozk2 05-21-2017 08:50 PM

I'm unable to make you a digital copy from my Rider's disk, copy protected for some reason.

VintagePC 05-21-2017 09:01 PM

Darn, appreciate you trying. Seems my local library has in-house Sams and Riders (hopefully the right volumes). If no luck here I can go take a look and spend some time on a photocopier if they have the right ones.

Is the Sams also a no-go? Even if not identical I'm curious whether it has additional info not in the Riders.

user181 05-22-2017 08:23 AM

Here's the SAMS available for purchase:

https://www.samswebsite.com/en/photo...index/id/66461

VintagePC 05-22-2017 05:45 PM

Given the above info that it might not be for the right set/revision, I'm sure as heck not dropping $15 on a SAMS.

Library did not pan out, only had SAMS up till volume 91, Riders was supposedly there but not on the shelf. They're gonna go hunting for it.

VintagePC 05-25-2017 08:26 PM

Looks like the flyback's been replaced. Cap lead to the HV rectifier was disconnected and some anti-arcing bodgery inside the HV cage. Probably arcing because there's a bad pointy solder joint on the clamp.

Lead is too short to reconnect, so perhaps the doorknob cap has also been replaced. Interesting, since the CRT also has a coating. Didn't think doorknobs + dags were common together but it could be because there are several revisions of this chassis, and the earlier ones were roundies.

Still getting my thoughts organized, replacing the caps I have on hand and figuring out what I need to order. I've obtained a SAMS and the Beitman's schematic, and hopefully will have the Riders soon too. More pictures coming this weekend!

old_coot88 05-25-2017 11:53 PM

Doorknobs and Dags. Sounds like something outa Edgar Allen Poe. :D:tongue:

VintagePC 05-26-2017 06:25 AM

...When suddenly there came a zapping, of corona gently snapping, snapping within my HV cage door...

VintagePC 05-27-2017 04:31 PM

A'right, some progress. Spent the day familiarizing myself with the set and figuring out what capacitors I'll need to order.

Started by taking a look at the focus control... it made nasty crunching noises when turned, and on opening, my suspicions were confirmed - it's burned up, as is common with some designs.

http://vintagepc.forceanature.com/si...m_IMG_0015.JPG

How likely am I to find an exact replacement? This is a dual-control with brightness. Rear control is 50K 1/2 watt, focus part (front) is 2500 ohms, 2 watt. Clarostat 25B889. Can always mount focus somewhere else on the rear of the chassis, but would be nice to retain it by the front knob where labelled.


There are also two sand resistors... as is the case with most, the leads are corroded and this one (while it still measured OK) fell apart when I looked at it funny. I didn't have the required value for the other one on hand, I'll have to order it.
http://vintagepc.forceanature.com/si...m_IMG_0017.JPG


Whoever replaced the flyback did some bodgery, and there was a half-baked attempt at squelching some arcs with electrical tape on the inside of the HV cage... Likely because the rectifier cap lead had a terrible solder joint with pointy stray wires everywhere. After unsoldering, there was enough folded/bunched up wire to make it long enough to reach again.... Nice clean and smooth joint now, and also added some heatshrink for good measure since the insulation on the lead was too short.
http://vintagepc.forceanature.com/si...m_IMG_0019.JPG
No, I didn't solder while it was connected to the rectifier... You can see the allen key I clamped to the chassis to hold the HV lead ring while soldering.

More flyback bodgery. Looks like somebody miscalculated wire length; those aren't original wires, so I'll clean that up at some point.
http://vintagepc.forceanature.com/si...m_IMG_0020.JPG

Another interesting thing... these piggy-backed fuses:
http://vintagepc.forceanature.com/si...m_IMG_0021.JPG
I could see this if a homeowner was too lazy to unsolder a fuse and just put a new good one in parallel... but both of these fuses measure good. Any idea why this might have been done?

Another interesting thing is that the doorknob cap under the rectifier isn't really connected to anything... it's bolted to the corona guard ring/mount for the HV rectifier, but that is isolated and just floats. Huh?

I'll also have to take a look at the flyback mounting... the transformer is kinda squished in in an odd position and the replacer bent the cage when replacing it to make it fit. Looks like it might be possible to neaten up if I reorganize the inside of the HV cage a little bit...
http://vintagepc.forceanature.com/si...m_IMG_0022.JPG
http://vintagepc.forceanature.com/si...m_IMG_0024.JPG

Notimetolooz 05-28-2017 12:42 PM

Maybe the previous person only had fuse values half as large as called for.:lmao:


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