Hallicrafters T-506 Late Production Set

[M3-SRT8]

25Z6 Readings. Also way off:

Pin 1: 60k Test Inf

Pin 2: 25 ohms Test 144k

Pin 3: 160k Test 1.3 meg and climbing

Pin 4: 64 ohms Test 144k

Pin 5: 10k Test 11.43k

Pin 6: 46 ohms Test Inf

Pin 7 26 ohms Test 144k

Pin 8: 60k Test 1.1 meg and climbing

Weird. And the chassis is recapped, and I've checked everything twice, at least.

[jr_tech]

Series string set...did you check all of the heaters and assure that tube pins are clean and making connection? 18 ohm resistor ok? All bets are off on the resistance readings until you have heater strings intact.

Also, did you notice that the Sams shows c4a & b connected backwards? that cap actually has common plus ! Riders has it correct.

jr

[M3-SRT8]

I already cleaned all the tube sockets with contact cleaner and a pipe cleaner.

I replaced all the 'Lytics as they were wired ex-factory, same grounding points, replaced all wiring with new. Double checked it. Tested all components before install.

Tested the tubes before fire up.

Would a dead selenium rectifier prevent start up? When I was waiting for an answer on the diode polarity I hooked up the rectifier and attempted to fire it up that way.

[M3-SRT8]

Both 18 ohm resistors near the rectifier test fine.

I had checked all resistors on the chassis before fire up. Replaced only the four 4.7 meg resistors in the sweep section as they were beyond 20%.

[M3-SRT8]

I have C4A and C4B common plussed to the ground on the 25Z6, just like the factory.

Still checking...

[old_coot88]

Any chance of posting a schematic?

[jr_tech]

There must be an open connection somewhere in the heater string if the tubes are not lighting... a bad selenium rectifier will not be a cause of the tubes not lighting.
Perhaps continuity check the heater strings from ground, working back to the power cord end... there must be an open circuit in the heater strings.
CRT heater ok? Fuse ok?

jr

[M3-SRT8]

How do I check the CRT heater? Fuse is ok.