The Mercury

[Adam]

Model 4188. Chassis 101 It uses the 12LP4.

This doesn't even appear in my Sams index, anyone know if there is a sams for this, if so I probably have it, if not does anyone have a schematic or know where to get one?

The finish really isn't as nice as in the ebay pics. Vineer is bad in places too. Some sets are clearly nice enough to leave the cabinet as is, others definetly need work, this is one of those sets where it's somewhere inbetween. I wish I knew more about repairing vineer, anyone recommend a good book or other source of information on the subject, I got a few other sets that need vineer work too. And the finish on this is odd, it's not really a clear finish, more like fake yellow wood grain painted on. Any thoughts on what it is?

The good stuff is that it's complete with both the back and the HV cage cover which are almost always missing from sets of this era. And it's like new behind the doors, the cloth is is excellent condition, all original knobs there. CRT tests good.
Here's some pictures...

[Steve K]

Adam:

I'm glad that you got that set. I probably have the schematic and I can help you out with the finish as well. Sent me a PM or email.

Steve

[John Marinello]

I looked up the 12LP4C, and it's listed as an aluminized tube that still requires a double field ion trap.

[doug621ts]

Hey Adam

Glad you got the set! If it were me I would leave the finish "as -is" as it will be very difficult to duplicate that blonde type finish or to touch up, I would paste wax the finish using the Johnsons paste floor wax to give it a decent shine, I bet it would display decently. To re-finish it in a dark stain would be awefull and very hard to do the blonde! The veneer chip does not look too bad, is there others that are bigger? I see the RCA type channel knob, does it have "channel one"? Good luck!

[Steve K]

Doug:

Adam brought the cabinet up to my place a few days ago and the original finish was too far gone to really make it look good. The original finish, as seen inside the doors and around the CRT, is a fairly yellowish blonde the was more of a paint than a stain. I was able to come fairly close to the original look using a combination of stains and lacquer.

BTW Adam, I want to fix that broken foot yet and it should be ready tomorrow.

Steve

[Adam]

With that knob I thought it had channel 1 too, but it doesn't. It's actually kind of a strange tuner in that it doesn't go all the way around it stops after 2 and 13.

[wajobu]

Cool set! Interesting pink quilted fabric around that picture tube.

Is that late 1940s-early 1950s vintage?

[Sandy G]

Can't wait to see pics of it "fired-up", Adam !

[Tubejunke]

Not just RCA type knobs but that chassis is VERY close to the typical RCA chassis of that vintage (late 40's to very early 50's). The differences I see are the lack of the long 3 in 1 bias network, flter resistor that the RCA's are known to have troubles with, and the control positioning looks different. The basic chassis and most of the tube positioning I can see looks nearly identical right down to the 12LP4.

[Adam]

Here is the cabinet after Steve K refinished parts of it. It looks good. Inside the doors is 100% original finish, the new stuff is on the outside.
It is similar to the RCA's, I'm going to fix up my 721ts next because I haven't ordered any caps for this one yet, so I'll be able to compare the two.
I'm not sure of the exact year, I think it must be '48-'50.

[doug621ts]

Very Nice Adam!....Very good job Steve looks wonderful! Have you powered this set up at all? I cant imagine very many Mercury sets around though it was made locally, just like the Kaye-Halbert that seldom show up though again made here locally.

[Adam]

I finished recapping this, but it's not working at all, no (or very little) HV no sound, no nothing. The filaments do light. I tried messing with the ion trap just to be sure it wasn't that, but if I go to discharge the 2nd anode after the tv was running, I don't see any sparks, so I'm pretty sure my problem is no HV. Now the power transformer is making some kind of buzzing noise, but I checked the voltages in the power supply, and it looks ok. I also hear the yoke ringing when I turn the horiz hold control. I checked the 1 meg resistor in series with the 2nd anode, and it tests good. I checked voltages on the HO tube and the damper, but the schematic I have is not the same as what's in the set, even though it says it's for this model, so I don't know if I should trust the voltage numbers on there. I'll draw over my schematic to show what's in there, then post it later.

[Adam]

I went and tested the HO tube, h osc tube, damper, and HV rect, HO tube tested a bit weak on the emission test but showed a lot of heater cathode leakage, horiz osc only slightly weak, damper tested ok but also showed alot of heater to cathode leakage, and 1B3 was weak. So I just went and swaped all of them at once to see what would happen, the picture tube lights up strong now, HV is good. I didn't have a 12AU7 (horiz osc), so I swaped it with a modern equivalent, a ECC82, I hope it will sync. I didn't have an antenna hooked up before, so I couldn't tell, now I'm going to go back and try. Power trans is still buzzing, I sure hope it doesn't short out, this set uses an unusual 2 tube power supply (5U4 and 6X5), so a replacement won't be easy to find.

[Adam]

The horiz doesn't sync, but it's the same with both the original tube and the new tube. But vert sync is fine, at least I have HV and I know the flyback is good.

[Adam]

Fixed the horiz sync, it was a bad resistor, had to put 2 in parallel to get the correct value, I'll have to get the correct replacement tomarrow. The ECC82 didn't work as a replacement for the 12AU7, but I put the original tube back and it seems to work. I left the new HV rect, damper, and HO tubes in.