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

Zenith 12-S-265 chassis #1204, questions on the LO
#3

Some sets go with the LO below the fundamental on the top band. There's no rule-of-thumb and no easy way to tell in advance. Plus I don't think I've ever seen any alignment instructions that would give a specific clue. Some will advise that there may be two peaks on the trimmer and to use one or the other.

Most radios will readily peak on either side AT the upper end alignment frequency on the top band. Image rejection on most consumer radios really stinks up there. But it will generally be obvious in tracking towards the low end if you have hit the incorrect peak.

That RCA that I recently did, Brian, was a classic case. It didn't align particularly well either way.

EDIT - an additional thought. I suppose a guy could sit down with a counter (or digital radio) and measure the LO at various points across the band compared with the dial - adding or subtracting the IF accordingly. One set of measurements *should* line up better than the other against the dial readout. I've never taken that approach and quite frankly some radios might be too poorly calibrated to tell but it might give a clue as to which injection side shows the most promise. -


Messages In This Thread
Re: Zenith 12-S-265 chassis #1204, questions on the LO - by exray - 09-13-2008, 08:59 PM



Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Philco 16B Parts
I think the chassis is painted.morzh — 08:13 PM
Philco 38-2 Automatic Tuning
Honestrly, the original is quite acceptable and, it seems to me, can be cleaned.morzh — 08:11 PM
Philco 41-608 changer coupler
Mondial left a thread about remanufacturing thois type coupler.morzh — 08:09 PM
IF can wire size and Rubber mounts?
Are you talking about rewinding or rewiring? For rewiring, meaning runnin wires to the coil from other components, the ...morzh — 08:08 PM
12' Philco
I wonder who would be able to "no stoop" with this one.morzh — 08:05 PM
IF can wire size and Rubber mounts?
Hello PHORUM members, I am still working on restoration of my PHILCO 37-640.  I want to start with rewiring the IF ca...georgetownjohn — 06:32 PM
Philco 41-608 changer coupler
I am working on a Philco 41-608 with the gear-driven changer.  The coupling (#35-2220) between the motor assembly and th...alangard — 06:29 PM
Gilfillan Brothers Car Radio?
There is a Mission Bell model 19/19A that could be what you’re looking for, Riders vol 4. It has the tube line-up of: 0Z...Joe Rossi — 05:01 PM
Looking for verification of correct schematic.
Definitely 870044RossH — 01:12 PM
12' Philco
Wonder if the chassis was big too.daveone23 — 12:38 PM

[-]
Who's Online
There are currently 3837 online users. [Complete List]
» 3 Member(s) | 3834 Guest(s)
AvatarAvatarAvatar

>