[Hallicrafters] SX-42 - trouble shooting weak and intermittent performance.

DJ via Hallicrafters hallicrafters at mailman.qth.net
Sat Jul 25 06:55:48 EDT 2015


Hi,

I haven't posted here in a while, new family, new job, sdrs etc...

Down to business, after several years of inactivity I broke out the SX-62 and the SX-42 and fired them up. Several years ago I gave them a both a good tune-up at the same time, one right after another over the course of a week if I remember correctly. They were completely recapped (even the cans) and realigned, some resistors were replaced that were way out of spec, looked burned, etc. At the time they were finished both were rocking.

Well only the 62 is knocking the shingles off the roof. The 42 is not exactly dead but is experiencing some problems. I am very much the amateur in fixing these but can manage quite well if I know where to concentrate and how to proceed. I have my trusty Heathkit VTVM so I should be able to hone in on the problem and get her back up to speed.

The problems are across all bands:

1. Audio intermittent and weak. Audio is about 1/2 to a 1/4 of what it should be when normal. Sometime the audio just just comes on but never at full
2. Weak reception/ insensitivity.
3. S/FM meter appears to not be working.

So far I've replaced all the tubes with the ones from the 62 and back again. These all seem to be fine. There is one oddity in this radio, the 7A4 has been replaced with a 7G7 and modified accordingly. The radio works with this and I left it alone rather than change it back. The previous owner was some major science professor and a Hallicrafters collector - why it was modded this particular way is unknown.

Any suggestions to get me going would be great.

http://www.iarc.org/~4z5to/SX42.php

73,
Douglas

------------------------------------------------
END OF MESSAGE

--------------------------------------------
On Mon, 7/20/15, hallicrafters-request at mailman.qth.net <hallicrafters-request at mailman.qth.net> wrote:

 Subject: Hallicrafters Digest, Vol 137, Issue 8
 To: hallicrafters at mailman.qth.net
 Date: Monday, July 20, 2015, 2:48 AM
 
 Send Hallicrafters mailing list
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 When replying, please edit your Subject line so it is more
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 than "Re: Contents of Hallicrafters digest..."
 
 
 Today's Topics:
 
    1. Re: Frivolous Hallicrafters SX-88 Post
       (Greg Gore via Hallicrafters)
    2. Re: Frivolous Hallicrafters SX-88 Post
       (Greg Gore via Hallicrafters)
    3. Re: Frivolous Hallicrafters SX-88 Post
 (Todd, KA1KAQ)
    4. Re: Frivolous Hallicrafters SX-88 Post
 (John via Hallicrafters)
    5. Re: Hallicrafters SX-88 (Jim Liles)
 
 
 ----------------------------------------------------------------------
 
 Message: 1
 Date: Sun, 19 Jul 2015 10:10:00 -0400
 From: Greg Gore via Hallicrafters <hallicrafters at mailman.qth.net>
 To: ka1kaq at gmail.com, hallicrafters at mailman.qth.net
 Subject: Re: [Hallicrafters] Frivolous Hallicrafters SX-88
 Post
 Message-ID: <14ea6a66698-2e07-1d186 at webprd-a85.mail.aol.com>
 Content-Type: text/plain; charset=utf-8
 
 
 
 Todd,
 Please, please calm down, this is not worth getting that
 upset over to the point you feel compelled to type out long
 angry replies at 11:30PM. The post was not intended to be a
 personal attack as you are a fellow long time 1-land ham and
 a fine person I believe but I do want to counter
 misinformation you post when I find it. I don't understand
 why you foster so much animosity toward the Hallicrafters
 SX-88. You've never owned one, nor operated a good one one
 but your hostility seems apparent every time you include
 yourself in discussions about them. I don't believe the
 SX-88 is the finest receiver of all time but I do think
 they're pretty good and they are somewhat scarce. Other
 receivers I have here that best it, and they should include:
 Icom IC-R9000, JRC NRD-545, HRO-600 and HRO-500
 Still, the SX-88 is a great receiver and an engineering
 masterpiece, especially considering the 1954 time frame and
 I've probably gone deeper into them than most would feel
 comfortable with except of course for Jay, W1VD, whom I've
 learned a lot from and highly respect. As Jay said, The
 SX-88 is the only receiver to ever use that particular IF
 transformer design and it's one of the main reasons the
 receiver is desireable. I'm at the point now where I don't
 bench test them first anymore, I strip everything away and
 rebuild the entire receiver back into good condition again.
 One improvement I am in the process of implementing is to
 begin aligning the 50KC 2nd IF amplifier with a Hewlett
 Packard HP3585 spectrum analyzer in order to exactly
 reproduce the original engineering curves for the IF
 response. Considering the number of hours and amount of work
 it takes to do good thorough work one does not restore SX-88
 receivers with the idea of lining their pockets. It is
 entirely a la
  bor of love, purely for the enjoyment and personal
 achievement because few go that far to that extent. I am
 keeping track of my time on my current job just to see
 exactly what I will have invested in it but I estimate a
 couple hundred hours each on earlier jobs. SX-88s are my
 passion and I do enjoy having success with them; it's a
 therapeutic diversion away from my day job which for the
 last 23 years has been my involvement in the engine lab for
 Hendrick Motorsports. We've won over 350 NASCAR races with
 the best and most popular drivers in the industry so I've
 been fortunate to enjoy sharing in the success there also.
 http://i104.photobucket.com/albums/m191/wa1kbq/SX-88%20-%20400/SX88-40026.jpg
 Ready for soaking with oil and a twist of the golden
 screwdriver
 
 
 Greg Gore
 WA1KBQ
  
 
 
 ------------------------------
 
 Message: 2
 Date: Sun, 19 Jul 2015 10:37:51 -0400
 From: Greg Gore via Hallicrafters <hallicrafters at mailman.qth.net>
 To: hallicrafters at mailman.qth.net
 Subject: Re: [Hallicrafters] Frivolous Hallicrafters SX-88
 Post
 Message-ID: <14ea6bfe9c5-2e07-1d22a at webprd-a85.mail.aol.com>
 Content-Type: text/plain; charset=utf-8
 
 
 
 Todd,
 
 Please, please calm down, this is not worth getting that
 upset over to the point you feel compelled to type out long
 angry replies at 11:30PM. The post was not intended to be a
 personal attack as you are a fellow long time 1-land ham and
 a fine person I believe but I do want to counter
 misinformation you post when I find it. I don't understand
 why you foster so much animosity toward the Hallicrafters
 SX-88. You've never owned one, nor operated a good one one
 but your hostility seems apparent every time you include
 yourself in discussions about them. I don't believe the
 SX-88 is the finest receiver of all time but I do think
 they're pretty good and they are somewhat scarce. Other
 receivers I have here that best it, and they should include:
 Icom IC-R9000, JRC NRD-545, HRO-600 and HRO-500
 
 Still, the SX-88 is a great receiver and an engineering
 masterpiece, especially considering the 1954 time frame and
 I've probably gone deeper into them than most would feel
 comfortable with except of course for Jay, W1VD, whom I've
 learned a lot from and highly respect. As Jay said, The
 SX-88 is the only receiver to ever use that particular IF
 transformer design and it's one of the main reasons the
 receiver is desireable. I'm at the point now where I don't
 bench test them first anymore, I strip everything away and
 rebuild the entire receiver back into good condition again.
 One improvement I am in the process of implementing is to
 begin aligning the 50KC 2nd IF amplifier with a Hewlett
 Packard HP3585 spectrum analyzer in order to exactly
 reproduce the original engineering curves for the IF
 response. Considering the number of hours and amount of work
 it takes to do good thorough work one does not restore SX-88
 receivers with the idea of lining their pockets. It is
 entirely a la
  bor of love, purely for the enjoyment and personal
 achievement because few go that far to that extent. I am
 keeping track of my time on my current job just to see
 exactly what I will have invested in it but I estimate a
 couple hundred hours each on earlier jobs. SX-88s are my
 passion and I do enjoy having success with them; it's a
 therapeutic diversion away from my day job which for the
 last 23 years has been my involvement in the engine lab for
 Hendrick Motorsports. We've won over 350 NASCAR races with
 the best and most popular drivers in the industry so I've
 been fortunate to enjoy sharing in the success there also.
 
 http://i104.photobucket.com/albums/m191/wa1kbq/SX-88%20-%20400/SX88-40026.jpg
 Ready for soaking with oil and a twist of the golden
 screwdriver
 
 Greg Gore
 WA1KBQ
 
  
 
 
 ------------------------------
 
 Message: 3
 Date: Sun, 19 Jul 2015 12:59:34 -0400
 From: "Todd, KA1KAQ" <ka1kaq at gmail.com>
 To: Hallicrafters Reflector <hallicrafters at mailman.qth.net>
 Subject: Re: [Hallicrafters] Frivolous Hallicrafters SX-88
 Post
 Message-ID:
    
 <CANCs6AVTSTsndtvjNXtyKEpjk2VG3FVhxkq8Gf9iskAWNk+c9g at mail.gmail.com>
 Content-Type: text/plain; charset=UTF-8
 
 On Sun, Jul 19, 2015 at 10:10 AM, Greg Gore <wa1kbq at aol.com>
 wrote:
 
  The post was not intended to be a personal attack as you
 are a fellow long
 > time 1-land ham and a fine person I believe but I do
 want to counter
 > misinformation you post when I find it.
 >
 
 Of course it's not, Greg. You just dug up a post from
 several years ago on
 another forum to make an issue over - despite the fact that
 there is no
 "misinformation" as you claim, simply opinions that differ
 from yours.
 
 
 >  You've never owned one, nor operated a good one
 one
 >
 
 Well, the first one I ever operated was restored by you. So
 you've got me
 there.
 
 but your hostility seems apparent every time you include
 yourself in
 > discussions about them.
 >
 
 Clearly you consider any opinion that differs from yours as
 'hostile' or
 some kind of attack. You see yourself as so important that
 someone stayed
 up late to pen a 'angry reply' to you, even. Fact of the
 matter is, I
 waiting for a call back from a fellow on the left coast
 about getting a car
 shipped here. Responding to your nonsense, though completely
 pointless,
 helped to pass the time. The pathetic part is, this is the
 most activity
 I've had on this list in months or years.
 
 One thing is certain Greg - you start these little episodes
 as
 opportunities to draw attention to yourself, your
 collection, your
 "accomplishments". As predictable as the rising and setting
 of the sun. The
 comments below prove this yet again.
 
 
 > Other receivers I have here that best it, and they
 should include: Icom
 > IC-R9000, JRC NRD-545, HRO-600 and HRO-500.....
 >
 > .....my day job which for the last 23 years has been my
 involvement in the engine lab for Hendrick Motorsports.
 We've won over 350 NASCAR races with the best and most
 popular drivers in the industry
 >
 > http://i104.photobucket.com/albums/m191/wa1kbq/SX-88%20-%20400/SX88-40026.jpg
 >
 >
 So responding just allows you to further publicize yourself
 and feed your
 ego, but that's okay. It's the least I can do for a fellow 1
 lander. I'd
 say it's been fun, but 'funny' is probably more accurate.
 
 Lunch is over. Back out to the Farmall and mowing. And we're
 done here. Or,
 at least, I am.
 
 /KAQ
 
 
 ------------------------------
 
 Message: 4
 Date: Sun, 19 Jul 2015 13:10:47 -0400
 From: John via Hallicrafters <hallicrafters at mailman.qth.net>
 To: wa1kbq at aol.com, hallicrafters at mailman.qth.net
 Subject: Re: [Hallicrafters] Frivolous Hallicrafters SX-88
 Post
 Message-ID: <11eb58.42201b50.42dd3417 at aol.com>
 Content-Type: text/plain; charset="US-ASCII"
 
 Enough already!
  
 73,
  
 John, W4AWM
  
  
  
  
  
  
 In a message dated 7/19/2015 11:10:37 A.M. Eastern Daylight
 Time,  
 hallicrafters at mailman.qth.net
 writes:
 
 
 
 Todd,
 
 Please, please calm down, this is not worth  getting
 that upset over to the 
 point you feel compelled to type out long angry 
 replies at 11:30PM. The 
 post was not intended to be a personal attack as you 
 are a fellow long time 
 1-land ham and a fine person I believe but I do want
 to  counter 
 misinformation you post when I find it. I don't understand
 why you  foster so much 
 animosity toward the Hallicrafters SX-88. You've never
 owned  one, nor operated a 
 good one one but your hostility seems apparent every
 time  you include 
 yourself in discussions about them. I don't believe the
 SX-88 is  the finest 
 receiver of all time but I do think they're pretty good and
 they  are somewhat 
 scarce. Other receivers I have here that best it, and they
 should  include: 
 Icom IC-R9000, JRC NRD-545, HRO-600 and HRO-500
 
 Still, the  SX-88 is a great receiver and an
 engineering masterpiece, 
 especially  considering the 1954 time frame and I've
 probably gone deeper into 
 them than  most would feel comfortable with except of
 course for Jay, W1VD, 
 whom I've  learned a lot from and highly respect. As
 Jay said, The SX-88 is 
 the only  receiver to ever use that particular IF
 transformer design and it's 
 one of the  main reasons the receiver is desireable.
 I'm at the point now 
 where I don't  bench test them first anymore, I strip
 everything away and 
 rebuild the entire  receiver back into good condition
 again. One improvement I 
 am in the process  of implementing is to begin aligning
 the 50KC 2nd IF 
 amplifier with a Hewlett  Packard HP3585 spectrum
 analyzer in order to exactly 
 reproduce the original  engineering curves for the IF
 response. Considering 
 the number of hours and  amount of work it takes to do
 good thorough work one 
 does not restore SX-88  receivers with the idea of
 lining their pockets. It 
 is entirely a la
 bor of  love, purely for the enjoyment and personal
 achievement because few 
 go that  far to that extent. I am keeping track of my
 time on my current 
 job just to  see exactly what I will have invested in
 it but I estimate a 
 couple hundred  hours each on earlier jobs. SX-88s are
 my passion and I do enjoy 
 having  success with them; it's a therapeutic diversion
 away from my day 
 job which for  the last 23 years has been my
 involvement in the engine lab for 
 Hendrick  Motorsports. We've won over 350 NASCAR races
 with the best and 
 most popular  drivers in the industry so I've been
 fortunate to enjoy sharing 
 in the success  there  also.
 
 http://i104.photobucket.com/albums/m191/wa1kbq/SX-88%20-%20400/SX88-40026.jp
 g
 Ready  for soaking with oil and a twist of the golden
 screwdriver
 
 Greg  Gore
 WA1KBQ
 
 
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 ------------------------------
 
 Message: 5
 Date: Sun, 19 Jul 2015 18:48:28 -0500
 From: "Jim Liles" <hallicrafterssr2000 at k9axn.com>
 To: <hallicrafters at mailman.qth.net>,   
 "Roy Morgan" <k1lky68 at gmail.com>
 Subject: Re: [Hallicrafters] Hallicrafters SX-88
 Message-ID: <28FE6EDB7A354D7F9824CADC6DD3E657 at LILESJLAPTOP>
 Content-Type: text/plain;    charset="utf-8"
 
 I would like to repeat an information request regarding the
 50Kc I.F. system used in the SX-88.  
 
 -----Original Message----- 
 From: Jim Liles 
 Sent: Thursday, July 16, 2015 7:21 PM 
 To: hallicrafters at mailman.qth.net
 ; Roy Morgan 
 Subject: [Hallicrafters] Hallicrafters SX-88 
 
 
 I have some questions regarding the SX-88.  
 
 First have you done a sweep analysis of the 50Kc I.F. system
 or do you know of someone who has?  At this point it
 appears that nobody has taken the time to sweep that system
 ---- anybody? 
 
 Can anyone confirm that the 50Kc I.F. charts in the book are
 correct?
 
 Looking at the design I would expect the shape factor for
 the system to be close to 2.2/1 which is very close to the
 crystal filters of that time.  Is that a correct
 analysis?
 
 Has anyone measured the Q of the first, second , and fourth
 50Kc transformer pairs as well as the third pair?
 
 More questions but sure would like to hear from those who
 have had one on the bench.  That radio is probably the
 most enigmatic of the Hallicrafters bunch.  Always
 wanted to put one through sea trials.
 
 Would like to hear both objective as well as subjective
 opinions and test results.  Sounds to be some strong
 feelings regarding that radio?s performance.  Please
 for the moment put the past aside and help me with this
 project.     
 
 Kindest regards Jim K9AXN  
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