[R-390] R-390 Digest, Vol 124, Issue 3
Frank Hughes
fsh396ss at gmail.com
Sun Aug 3 18:59:48 EDT 2014
Hi,
This R-390 is the same Hamfest "tailgate special" that I have been working
on for a while now.
When it was repaired enough to receive a signal on 3 megacycles, I started
to see how to get the other bands working, as it was "deaf" on many.
At the time, I did not know if it was just an alignment issue and/or more
defective components, as we found with the power supply and IF deck.
I have had the crystal deck out, but lost track of which one is in there
now - my spare? the original?
It is not too difficult to get in and out, except for aligning that goofy
coupler.
I am going to assume, at the risk of this forum exploding, that using the
ultrasonic cleaner on the trimmers is "bad" (running for cover now...)
I do have a video training tape from Chuck that contains an explanation of
how to disassemble and clean a trimmer.
Looks like there are only about 3472987 of them in the crystal deck.
I would like to be able to test crystals, there is probably some way I can
use the spectrum analyzer and signal generator to do it.
I have another method that Roy described using the generator and 410C VTVM
w/ RF probe, but the scope or the SA/TG would be fun to learn how to do.
Here is what the IF output looks like, I wanted to see if there was a way
to adjust Z501 using the SA, but no matter how I changed the trimmer and
coil, it did not effect this trace.
http://i180.photobucket.com/albums/x257/fish1_07/R-390/z501-sa_zps56a0c951.jpg
73
Frank
KJ4OLL
On Sun, Aug 3, 2014 at 6:19 PM, <r-390-request at mailman.qth.net> wrote:
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> Today's Topics:
>
> 1. Re: Ultrasonic cleaning (Roy Morgan)
> 2. R-390 alignment attempt #1, need advice - Crystal Deck
> (Frank Hughes)
> 3. Re: R-390 alignment attempt #1, need advice - Crystal Deck
> (Bob Camp)
> 4. Re: R-390 alignment attempt #1, need advice - Crystal Deck
> (Doug Massey)
> 5. Re: R-390 alignment attempt #1, need advice - Crystal Deck
> (Roger Ruszkowski)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Fri, 1 Aug 2014 14:47:49 -0400
> From: Roy Morgan <k1lky68 at gmail.com>
> To: Chris Farley <kc9ieq at yahoo.com>
> Cc: 390 List <r-390 at mailman.qth.net>
> Subject: Re: [R-390] Ultrasonic cleaning
> Message-ID: <635A4E5B-6749-4714-8768-F35A502C7FC7 at gmail.com>
> Content-Type: text/plain; charset=us-ascii
>
>
> On Jul 31, 2014, at 12:42 PM, Chris Farley via R-390 <
> r-390 at mailman.qth.net> wrote:
> >
> >
> > The antifreeze in a crock pot is a very intriguing idea!! It would both
> be a mild solvent, and serve to basically steam clean the parts..
>
> DO NOT LET ANY DOGS GET TO THE ANTIFREEZE!!
>
> One or two licks will KILL a dog. The stuff tastes sweet to them and they
> like it. Goodbye dog.
>
> Roy
>
> Roy Morgan
> RoyMorgan at alum.mit.edu
> K1LKY Since 1958
>
>
>
> ------------------------------
>
> Message: 2
> Date: Sun, 3 Aug 2014 16:39:10 -0400
> From: Frank Hughes <fsh396ss at gmail.com>
> To: r-390 at mailman.qth.net
> Subject: [R-390] R-390 alignment attempt #1, need advice - Crystal
> Deck
> Message-ID:
> <CAKLfjC=
> er-+yqVC83aZf6t-Sd73ykNw9fmPy-MeHANmj0_pGqA at mail.gmail.com>
> Content-Type: text/plain; charset=UTF-8
>
> Hi,
> I went through the first pass of alignment on the R-390, found some things
> that need attention, not sure how to proceed.
>
> Section 77 , Chapter 3 "Repairs and Adjustments" in TM 11-5820-357-35.
> "Alignment of Second Crystal Oscillator"
>
> Some of the crystals won't adjust w/ the trimmer.
>
> Initially did not think this was important, as they are bands I don't use.
>
> But by the time I got to the RF deck alignment, it became clear that I will
> have to fix them.
>
> All the manual says is "If no indication is obtained, check the
> "Crystal-oscillator bandswitch".
>
> If the "Crystal-oscillator bandswitch" is the big wafer switch inside the
> crystal deck, I might be able to get some Deoxit on the wipers/traces, but
> WOW, that thing is buried.
>
> But could the problem also be a dirty trimmer and/or bad crystal?
>
> I have a spare crystal deck to swap parts out of, if needed.
>
> Thanks & 73
> Frank
> KJ4OLL
>
>
> ------------------------------
>
> Message: 3
> Date: Sun, 3 Aug 2014 16:42:02 -0400
> From: Bob Camp <kb8tq at n1k.org>
> To: Frank Hughes <fsh396ss at gmail.com>
> Cc: r-390 at mailman.qth.net
> Subject: Re: [R-390] R-390 alignment attempt #1, need advice - Crystal
> Deck
> Message-ID: <78D8BE67-236B-4148-A3EE-C3EAADD86973 at n1k.org>
> Content-Type: text/plain; charset=us-ascii
>
> Hi
>
> Crystals will not adjust or the oscillator is dead on those bands?
>
> Bob
> KB8TQ
>
> On Aug 3, 2014, at 4:39 PM, Frank Hughes <fsh396ss at gmail.com> wrote:
>
> > Hi,
> > I went through the first pass of alignment on the R-390, found some
> things
> > that need attention, not sure how to proceed.
> >
> > Section 77 , Chapter 3 "Repairs and Adjustments" in TM 11-5820-357-35.
> > "Alignment of Second Crystal Oscillator"
> >
> > Some of the crystals won't adjust w/ the trimmer.
> >
> > Initially did not think this was important, as they are bands I don't
> use.
> >
> > But by the time I got to the RF deck alignment, it became clear that I
> will
> > have to fix them.
> >
> > All the manual says is "If no indication is obtained, check the
> > "Crystal-oscillator bandswitch".
> >
> > If the "Crystal-oscillator bandswitch" is the big wafer switch inside the
> > crystal deck, I might be able to get some Deoxit on the wipers/traces,
> but
> > WOW, that thing is buried.
> >
> > But could the problem also be a dirty trimmer and/or bad crystal?
> >
> > I have a spare crystal deck to swap parts out of, if needed.
> >
> > Thanks & 73
> > Frank
> > KJ4OLL
> > ______________________________________________________________
> > R-390 mailing list
> > Home: http://mailman.qth.net/mailman/listinfo/r-390
> > Help: http://mailman.qth.net/mmfaq.htm
> > Post: mailto:R-390 at mailman.qth.net
> >
> > This list hosted by: http://www.qsl.net
> > Please help support this email list: http://www.qsl.net/donate.html
>
>
>
> ------------------------------
>
> Message: 4
> Date: Sun, 3 Aug 2014 18:04:24 -0400
> From: Doug Massey <dougmassey at masseyradiolabs.com>
> To: Frank Hughes <fsh396ss at gmail.com>
> Cc: "r-390 at mailman.qth.net" <r-390 at mailman.qth.net>
> Subject: Re: [R-390] R-390 alignment attempt #1, need advice - Crystal
> Deck
> Message-ID: <B0385B1E-581D-4FD9-8FC6-3CD6509E9965 at masseyradiolabs.com>
> Content-Type: text/plain; charset=us-ascii
>
> Hey frank
> You may need to pull the whole Crystal deck out. Which is probably not
> what you wanted to do. Take all the trimmers apart clean them and put them
> back together. Could be those trimmers are just stuck. It is a common
> problem with those things. While you're in there you want to clean all
> those wafers as you pointed out with deoxit. Sometimes the same thing
> happens adjusting any of the ceramic trimmers in the radio. If you have
> that assembly apart make sure you check all of them before you put it back
> together. Overlooking those trimmers while module is out of the radio can
> sometimes come back to bite you when you do the alignment especially
> Crystal deck and RF deck
> Good luck with it. I am sure you will get it going. This is a great
> group of guys with a lot of experience and great information
> Doug
>
> Doug Massey N4ZZT
> Massey Radio Labs
> Johnston SC
> www.masseyradiolabs.com
>
> Sent from my iPhone
>
> > On Aug 3, 2014, at 4:39 PM, Frank Hughes <fsh396ss at gmail.com> wrote:
> >
> > Hi,
> > I went through the first pass of alignment on the R-390, found some
> things
> > that need attention, not sure how to proceed.
> >
> > Section 77 , Chapter 3 "Repairs and Adjustments" in TM 11-5820-357-35.
> > "Alignment of Second Crystal Oscillator"
> >
> > Some of the crystals won't adjust w/ the trimmer.
> >
> > Initially did not think this was important, as they are bands I don't
> use.
> >
> > But by the time I got to the RF deck alignment, it became clear that I
> will
> > have to fix them.
> >
> > All the manual says is "If no indication is obtained, check the
> > "Crystal-oscillator bandswitch".
> >
> > If the "Crystal-oscillator bandswitch" is the big wafer switch inside the
> > crystal deck, I might be able to get some Deoxit on the wipers/traces,
> but
> > WOW, that thing is buried.
> >
> > But could the problem also be a dirty trimmer and/or bad crystal?
> >
> > I have a spare crystal deck to swap parts out of, if needed.
> >
> > Thanks & 73
> > Frank
> > KJ4OLL
> > ______________________________________________________________
> > R-390 mailing list
> > Home: http://mailman.qth.net/mailman/listinfo/r-390
> > Help: http://mailman.qth.net/mmfaq.htm
> > Post: mailto:R-390 at mailman.qth.net
> >
> > This list hosted by: http://www.qsl.net
> > Please help support this email list: http://www.qsl.net/donate.html
>
>
> ------------------------------
>
> Message: 5
> Date: Sun, 3 Aug 2014 18:19:03 -0400 (EDT)
> From: Roger Ruszkowski <flowertime01 at wmconnect.com>
> To: fsh396ss at gmail.com, r-390 at mailman.qth.net
> Subject: Re: [R-390] R-390 alignment attempt #1, need advice - Crystal
> Deck
> Message-ID: <8D17D801121A514-33E0-1E11D at webmail-d234.sysops.aol.com>
> Content-Type: text/plain; charset="us-ascii"
>
>
> Frank,
>
> You did not mention if this R390 was new to you.
> Or had it worked OK in the past.
> Or you just do not know if it has worked in the past.
>
> It is fixable.
>
> But it is an R390.
>
> Getting into the crystal deck of the R390 is more complex than on the
> R390A.
>
> The crystals come un seated in the oven and the terminals pins of the
> crystals get
> oxidized.
>
> And if the receiver was not stored in a heated place and allowed to freeze
> real good
> some of the crystals may have given it up.
>
> As long as you have to do this maintenance procedure there is no reason to
> do only part of it.
>
> Your going to have to pull the RF deck and the crystal oscillator deck as
> a pair.
>
> You are going to have to open the oven covers (two layers) to get to the
> crystals.
> Once you get that far into the receiver you can get to the trimmer caps
> and the
> big selector switch.
>
> Pull all the crystals and clean (deoxit) the pins and sockets.
> Clean up the caps but not necessary to disassemble them.
> Clean up the selector switch contacts.
>
> If the missing ones are hit and miss then its likely crystal need sockets
> and pins cleaned.
> If every thing drops out on one end or the other it can be selector switch
> mechanical alignment.
>
> As long as you have the RF deck out to get to the crystals you should do
> the whole RF deck
> cleaning and lubrication maintenance and check the RF band switch
> alignment.
>
> Worry not about that green gear thing its way over rated.
> But if you have it use it.
> If not you will just have to make sure things are aligned as you reinstall
> the RF deck.
>
> Then you can put every thing back together and see how many mega hertz
> bands you recovered.
> You can look at the missing mega hertz bands and decide if it a crystal
> with all of its harmonics missing
> or a trimmer cap as some of the crystal fundamentals and harmonics are
> there.
>
> And see what is still missing then you can swap in some crystals from your
> spare deck.
> Or ask the fellows for some help with the crystals you think you need.
>
> Then you can take it all apart again to install the crystals.
>
> It Is not hard to do. It is just a slow screw job going both ways and
> takes time.
>
> Moving these receivers down the road takes out more crystals than any
> thing.
> The crystals just do not like to be bounced around.
>
> Frank if you need some R390 photos put up another post and I will send you
> some direct
> from a R390 rebuild I did a couple years ago.
>
> It could be worth your time to bread board up a crystal oscillator that you
> use to check the fundamental of all the crystals with. Just looking at the
> output level with a scope.
>
> Trying to match up the stray capacitance to see if they are on frequency
> will not be of much value.
> The crystals will oscillate or not oscillate.
> Once you get a circuit built up that some crystals work in then you can
> expect that the ones that do not work are bad.
>
> It will be a combination of things. a bad crystal, a dirty trimmer, a
> loose crystal, an oxidized switch contact.
>
> A good maintenance cleaning will cure every thing except the real bad
> parts.
> And the few problems that remain will be easy to diagnose and resolve.
>
> Roger AI4NI
>
>
> -----Original Message-----
> From: Frank Hughes <fsh396ss at gmail.com>
> To: r-390 <r-390 at mailman.qth.net>
> Sent: Sun, Aug 3, 2014 4:39 pm
> Subject: [R-390] R-390 alignment attempt #1, need advice - Crystal Deck
>
>
> Hi,
> I went through the first pass of alignment on the R-390, found some things
> that need attention, not sure how to proceed.
>
> Section 77 , Chapter 3 "Repairs and Adjustments" in TM 11-5820-357-35.
> "Alignment of Second Crystal Oscillator"
>
> Some of the crystals won't adjust w/ the trimmer.
>
> Initially did not think this was important, as they are bands I don't use.
>
> But by the time I got to the RF deck alignment, it became clear that I will
> have to fix them.
>
> All the manual says is "If no indication is obtained, check the
> "Crystal-oscillator bandswitch".
>
> If the "Crystal-oscillator bandswitch" is the big wafer switch inside the
> crystal deck, I might be able to get some Deoxit on the wipers/traces, but
> WOW, that thing is buried.
>
> But could the problem also be a dirty trimmer and/or bad crystal?
>
> I have a spare crystal deck to swap parts out of, if needed.
>
> Thanks & 73
> Frank
> KJ4OLL
> ______________________________________________________________
> R-390 mailing list
> Home: http://mailman.qth.net/mailman/listinfo/r-390
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:R-390 at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>
>
>
>
> ------------------------------
>
> Subject: Digest Footer
>
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>
> ------------------------------
>
> End of R-390 Digest, Vol 124, Issue 3
> *************************************
>
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