Welcome Guest! Be sure you know and follow the Phorum Rules before posting. Thank you and Enjoy! (January 12) x

Thread Closed
Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5

IF Alignment 41-290
#1

I am attempting to align the IF circuit on a 41-290. All seems to have gone well except it appears there is no sensistivity to adjustment of trimmer 32A (I believe this is a slug in the coil). Is there something wrong since output appears to be unaffected by adjustment of 32A or is this simply the way it is.
The unit appears to play well, I was just surprised that trimmer 32A had no affect.
#2

That slug should have a major effect on sensitivity. Can you see if the slug is actually moving up and down?

Richard
#3

Without removing the IF can, I can't tell if the slug is actually moving. The unit appears to work nicely and I hate to tear into something that might not be broke.

Thanks for your input.
#4

Had the same problem on my 37-610 and opened the can and found a broken coil connection at the trimmer. You will likely find something similar. It will likely be an easy repair.

Richard

Richard
#5

Agree, but you should be able to tell if slug is moving by marking the tool you are moving (It should go up or down depending on how you are turning it.) If you are way out of range it could appear to have no effect. You should be able to read the coil resistances without disassembly of the can. You can also check if there are any shorts between primary and secondary windings. The caps inside are a differrent story. If you do tear this down, just replace 'em.




Users browsing this thread: 3 Guest(s)
[-]
Recent Posts
The speaker table error?
G  10-1/2"       65, 76, 87, 95 Push-Pull 45's 2766 0.7 550 3200 H   10-1/2"    77, 96 Push-Pull...morzh — 09:26 PM
A Marconi model 86
I have a Stromberg, one of the early ones, seems early 30s. This is what I call a back breaker. None of the early Philc...morzh — 08:28 PM
A Marconi model 86
A backbreaker.....PaulPaul Philco322 — 08:12 PM
A Marconi model 86
>>What a behemoth! A Juggernaut.morzh — 07:47 PM
Philco 70 antenna lead
I am not sure I understood about the coils and the mush. I looked an more than one coil in 20, 70, 90, 60, Zeniths and ...morzh — 07:46 PM
A Marconi model 86
:e_biggrin: What a behemoth!  I hope the final result is as much a quality sounding example!  Keep us posted on your pro...GarySP — 07:32 PM
A Marconi model 86
I should add that the double conversion may only be used on the shortwave bands, but I haven't looked at the schematic t...Arran — 07:27 PM
Philco 70 antenna lead
Yes, that wire will not pick up much interference as routed - the RF at that level won't be affected, and if you have st...radio1 — 07:26 PM
Philco model 60
I'm also a member of MARC. Did you attend the Vintage Electronics Expo in Waterford, MI last month? That's where I got...GarySP — 07:22 PM
A Marconi model 86
Dan Double conversion is using two IF converters instead of one. This improves the image response. morzh — 07:15 PM

[-]
Who's Online
There are currently no members online.

>