An interesting 7" TV on eBay

[Tom9589]

rld-tv01, the picture in your referenced article looks just like the picture in the eBay ad. The grill arrangement is the same as well as the "missing" nameplate.

[rld-tv01]

See Meck XB-702 picture and schematic at http://www.earlytelevision.org/pdf/m...01_rider_3.pdf

[decojoe67]

Aha! That's the first time I've seen those 3 Meck models. I'd like to find the portable version.
Well that solves it. It's a '49 Meck with the nameplate missing. It definitely one of the lesser seen 7" sets, although far from one of the most appealing.
Here's another example from the Net. This one is also missing the small brass plaque - or maybe it's the same set.
https://link.springer.com/content/pd...014-0778-x.pdf

[Tim]

The set in the article is obviously very special as it includes "tube semiconductors".

[Yamamaya42]

Originally Posted by Tim

The set in the article is obviously very special as it includes "tube semiconductors".

tube semiconductors?

huh?

[Tom9589]

The only semiconductor I could find is the selenium rectifier in the power supply. They even use a tube for the video detector.

[Dj3928]

I have a Meck XA-701 that I just finished the restoration on. They are a pretty rare set and hopefully the buyer will restore it.
Mine has a metal grille on the front

[Jeffhs]

Originally Posted by init4fun

A second look at the chassis reveals that the tube sockets are riveted to the chassis , If this were a kit I'd expect to see screws with nuts and lock washers VS the rivets ?

I had to read your reply twice to make sure I understood it correctly. That is, I couldn't quite believe any television manufacturer would ever, even in the 1950s, rivet the set's tube sockets to the chassis. How on earth did they expect any TV repair shop to replace the tube sockets if they were solidly riveted in place? That is, I understand they could drill out the rivets to remove the defective socket, but that seems like an awful lot of work, not to mention the risk of damaging the chassis from the vibration of the drill. Using screws and nuts to mount tube sockets to the chassis makes a lot more sense, as all the technician would need to do would be to remove them from the holes on either side of the socket(s).

[WISCOJIM]

Originally Posted by Jeffhs

That is, I couldn't quite believe any television manufacturer would ever, even in the 1950s, rivet the set's tube sockets to the chassis. How on earth did they expect any TV repair shop to replace the tube sockets if they were solidly riveted in place?

I had to read your reply twice to make sure I understood it correctly. Are you serious? Have you ever looked inside a radio or TV before? Ever looked at pictures of chassis right here in this forum?

Of course they were riveted in place.

.

[decojoe67]

Originally Posted by WISCOJIM

I had to read your reply twice to make sure I understood it correctly. Are you serious? Have you ever looked inside a radio or TV before? Ever looked at pictures of chassis right here in this forum?

Of course they were riveted in place.

.

Just wanted to add that a common issue with early electrostatics is intermittent audio/video static often due to these rivets. On my early-run VT-71 I brushed every rivet and applied wire glue over and around them. It solved the problem.

[Electronic M]

Originally Posted by WISCOJIM

I had to read your reply twice to make sure I understood it correctly. Are you serious? Have you ever looked inside a radio or TV before? Ever looked at pictures of chassis right here in this forum?

Of course they were riveted in place.

.

Most molded plastic sockets if the metal contacts wore out or the solder tab broke off you could replace individual metal contacts by removing all soldered leads and solder, flattening the contact and pushing it up from the bottom...I've done this many times. The plastic sockets only ever needed a full socket replacement if the plastic insulator arced through or was otherwise severely damaged....Which is pretty rare even among socket failures which are themselves rare.

The phenolic wafer sockets weren't as serviceable but were fairly reliable. The only times I have had to replace them were when in a set that had been so soaked in rodent urine that the socket insulator had become conductive and was burning from the B+ current, and a couple of times I wasn't gentle enough and ripped a solder lug off...most repairmen back then favored J-hooks or snipping the old lead and tack soldering the new one to the surface of the existing solder blob so they wouldn't rip lugs off a socket under their normal practices.

[Polaraligned]

Riveting was the "norm" dating back to the earliest metal radio chassis in the 20's. You drilled the rivet out if socket was bad. No big deal as they were mostly dead soft brass usually plated.