[Hammarlund] HQ140 - really *LOW* sensitivity

[Bill Breeden]

Bob,

Don't know what kind of antenna you are using, but all of the Hammarlunds 
that I have owned have a balanced antenna input with three terminals on the 
antenna terminal strip.  The terminal strip on my HQ-145 is marked "A", "A", 
and "G" from left to right.  If you are using any antenna other than a 
balanced antenna with a balanced feed line, a short jumper or strap should 
be used to connect the center "A" and right hand "G" terminals together.  I 
often use a random single wire antenna on the left "A" terminal and the 
jumper between the other "A" and "G" makes all the difference.

73,

Bill - NA5DX


> ----------------------------------------------------------------------
>
> Message: 1
> Date: Tue, 15 Jan 2013 11:54:42 -0800 (PST)
> From: na2x at yahoo.com
> To: "hammarlund at mailman.qth.net" <hammarlund at mailman.qth.net>
> Subject: [Hammarlund] HQ140 - really *LOW* sensitivity
> Message-ID:
> <1358279682.91650.YahooMailNeo at web121704.mail.ne1.yahoo.com>
> Content-Type: text/plain; charset=iso-8859-1
>
> I'm working on a HQ-140X trying to get it into working order. I've spent 
> many hours trying to figure out what's going on with it but so far, no 
> luck.
>
> The radio basically works, but the sensitivity is really low on it. Yes, 
> the sensitivity control is at max. The only AM station I can pick up is 
> our local 50KW clear channel station. It comes in about S4 on the meter. 
> Other than being weak, it sounds OK.
>
> Here's the puzzle. Quite by accident, I had the aluminum cover off the 
> variable tuning capacitors on top of the chassis. I noticed when I bring 
> my hand near the antenna trimmer cap, the sensitivity comes way up. If I 
> touch the trimmer cap, the radio really comes alive to the point where I 
> think it's working as it should (if it would only stay like that). The 
> local 50KW station almost pegs the S meter.
>
> To me it sounds like something in the antenna input circuitry but I've 
> traced the wires to the switch and that area, checked the antenna coils 
> for continuity, checked grounds, and haven't found anything. Should I 
> continue looking in this area or does anyone have any other suggestions?
> ?
> I'm just about ready to through in the towel, I've spent way too much time 
> on it. I really don't want to give up on this receiver, it's a nice one 
> and it's in really good shape.
>
> Thanks,
> Bob NA2X