[Hallicrafters] S-41 alignment

[Kenneth G. Gordon]

> Hello all
> I'm trying to align an S-41

I have a couple of those. Restored at least one.

> 
> Any special tricks? Does the L.O operate above or below on bands 2 and 
> 3, and is the image rejection really as bad as it appears, (hammered by 
> broadcast while trying to find WWV on 5 MHz), or is it something I've 
> done wrong?

I guess it depends on how close those broadcast stations are to your 
location. I don't have that sort of trouble at all on band 2, nor really on 
band 3 either. I just have trouble FINDING WWV on band 3.

In fact, I use my S-41G all the time for operating on 40 meters and find 
the receiver to be a good performer there.

The preformance on band 3 leaves a lot to be desired, and I have never 
gotten mine to operate in what I would call "a proper manner" on band 
three.

I think the LO is above on bands 1 and 2, and below on band 3. I know 
of several S-38 owners who discovered this and the S-38 is a near 
clone of the S-41. I intend to find out soon enough and will post that 
info here.

BTW, the S-41G has a REAL BFO, which gives it a considerable 
advantage over especially the later model S-38(*).

My S-41s operated quite well on band 2, and when I was very young 
and didn't know any better, I used an S-41G for operation on 20 meters 
with good results.

My most recent S-41G, the one that I electrically restored, works very 
well on bands 1 and 2, and so-so on band 3.

BTW, both my first S-41G and my latest one have that funky bit of slug-
on-a string method for bandspread. The earlier models had a single-
plate capacitor for bandspread and those are noticeably more stable.

For my latest S-41G, I mounted a small filament transformer to an 
existing hole, and swapped the 12SA7 to a 6SB7Y, which has a much 
higher transconductance than the other tube.

To balance the filament string, I used a 50L6 in place of the 35L6. It 
plugged directly in with no modifications. Then took the 12SA7 out of 
the filament string.

This significantly improved sensitivity on all bands, but most especially 
on band 3. It also significanly reduced receiver internally generated 
noise.

Also, I added an IF gain control to mine, mounted externally to the right 
side, on a small bit of bent aluminum and used one of the bottom plate 
screws to hold it in place. All this is is a 10K pot in the cathode of the IF 
amp tube.

This makes a very big difference in making the copying of strong 
signals easy.

Even with all this, operation on band 3 is still marginal. However, I 
intend to revisit that problem as soon as I can.

They are a really fun receiver...except for the fact that they are AC/DC. 
I have a heavy isolation transformer I use with mine.

Before I got smart that way, I accidentally brushed a ground wire across 
the antenna connector one time with the power plug in the socket 
wrong-way-round, blew the house circuit breaker, and burned out the 
antenna coupling coil. Fortunately, that was easy to find and fix.

Ken W7EKB