[Hallicrafters] SX-42 info needed

Sun Apr 12 07:33:58 EDT 2009

I guess Ive been lucky so far as Ive had no IF can problems in any Halli 
receiver sofar. The pair of SX-62A's get daily use. I believe I replaced 
around 16 resistors in each. However the silver mica disease is a major 
problem in many of the 50-60's house radios I work on.

The one Im waiting to act up here is the HQ-180, knock on wood as its a 
solid performer so far.

RF stage trimmer caps are my general headache across several 
manufacturers, and I replace with new ARCO's rather than get frustrated. 
Also replacing the ceramic or mica trimmers with subminiature Johnson 
air variables has stabilized many a radios LO on the highest range.

So far no bad bandswitches on 42/62's but I have a 62 hulk for parts if 
that nightmare should arise.

Carl
KM1H

----- Original Message ----- 
From: "Rodger" <wq9e at dtnspeed.net>
To: "Carl" <km1h at jeremy.mv.com>
Cc: "Hallicrafters List" <hallicrafters at mailman.qth.net>
Sent: Saturday, April 11, 2009 10:18 PM
Subject: Re: [Hallicrafters] SX-42 info needed

> Carl,
>
> It the mica caps in the discriminator can aren't bad I will be 
> surprised.  I have three SX-62 receivers (had one for a week as a 
> novice so I have some perverse desire for them), one SX-42, and one 
> S-36A and they all had bad micas in the discriminator.  One of the 
> 62's had a bad mica in one 455 IF but other than that I didn't have 
> any other mica troubles.  Several of them required disassembly and 
> cleaning of the 455 Khz. filter crystal-not that it is that useful on 
> the fast tuning SX-62 series.  I also found some troubles with leakage 
> on the ceramic trimmer caps in the front end but again I think that 
> was largely due to the indiscriminate use of cleaning/lubrication 
> products.
>
> I have been lucky not to have the arcing bandswitch trouble but one of 
> the SX-62's had been literally drowned in tuner cleaner/lube by the 
> previous owner and among its effects was the oscillator died on the 
> upper end of the two highest frequency ranges.  I used about a can of 
> cleaner/de-greaser designed for electric motors and finally got it 
> working properly again.  Most of the out-of-tolerance resistors  found 
> were in the higher wattage units and unlike some of the National 
> receivers I didn't run into a lot of problems with the 1/2 watt units.
>
> Rodger WQ9E
>
> Carl wrote:
> Ive restored several SX-42's but never paid much attention to the run
> differences. Those and SX-62's are fun radios to work on!
>
> OK on the micas, its becoming a regular occurance in the past few 
> years
> across all brands, boatanchors, auto and house radios. That and the IF
> micas.
>
> Just finishing a HRO-60 that at least 2 others have had their fingers
> into; what a mess of wrong values caps and miswiring! Plus about 20
> resistors, 3 dogbones and one mica were way out of tolerance. Its one
> hot radio now and I havent even done any alignment. At least its easy 
> to
> work on.
>
> As fast as one goes out another comes in, keeps me out of trouble.
>
> Carl
>
> ----- Original Message ----- 
> From: <HallicrafterSX28 at aol.com>
> To: <Hallicrafters at mailman.qth.net>
> Sent: Saturday, April 11, 2009 9:14 PM
> Subject: Re: [Hallicrafters] SX-42 info needed
>
>
>  You are welcome,Carl. Good luck on the restoration! The one I just
> finished working  on had  a bad wafer switch causing B+ to affect the
> AVC bus!
> Luckliy the problem occurs  only on the two highest bands.
> Be on the lookout for bad silver micas ,and there is no shortage of
> them in
> these SX-42's !!
> Regards
> AMK"Nick"
>
> In a message dated 4/11/2009 5:23:12 PM Pacific Daylight Time,
> km1h at jeremy.mv.com writes:
>
> Thanks  Nick.
>
> Carl
>
>
> ----- Original Message ----- 
> From:  <HallicrafterSX28 at aol.com>
> To:  <Hallicrafters at mailman.qth.net>
> Sent: Friday, April 10, 2009 7:53  PM
> Subject: Re: [Hallicrafters] SX-42 info needed
>
>
>     Yes, you've got yourself an early version Run1 Sx-42.I've got one
> sitting
> here right in front of me on the bench.
> There 3  different SX-42 manuals out there .the one that applys to
> this
> one
> is dated 'June 1947'
> Regards
> AMK"Nick"
>
> In a message dated 4/10/2009 4:48:16 PM Pacific  Daylight Time,
> km1h at jeremy.mv.com writes:
>
> How  are  the run # determined? The one that just arrived is serial
> HA
> 63007 and  there are no run stamps on the chassis...unless this is
> Run
> 1.
>
> Carl
> KM1H
>
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