[R-390] R-390 Digest, Vol 59, Issue 33

Sun Mar 29 11:50:40 EDT 2009

Glass bead (fine grade) works extremely well on panels and knobs, but use caution on delicate items. I  have done numerous knob sets and panels over the years--all with good results. NEVER use silica sand as it will embed in the metal. I recently did an SP 600 chassis with walnut shell and it was OK but was really more of a thorough cleaning than metal refinishing. Soda blasting would have been a better choice for the chassis. If I were setting up for production I would have both, but since I only do one a month I get by with the glass bead machine and a handheld blaster (Harbor Freight) that I use with walnut shell (McMaster Carr).
Skip 
K7YOO
--- On Sat, 3/28/09, r-390-request at mailman.qth.net <r-390-request at mailman.qth.net> wrote:

From: r-390-request at mailman.qth.net <r-390-request at mailman.qth.net>
Subject: R-390 Digest, Vol 59, Issue 33
To: r-390 at mailman.qth.net
Date: Saturday, March 28, 2009, 11:00 AM

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Today's Topics:

   1. Re: SERIAL 163 FOLLOW UP (David Wise)
   2. Re: SERIAL # 163 (Pedro Del Valle)
   3. media vs soda blaster (odyslim at comcast.net)
   4. Re: media vs soda blaster (Chris Kepus)

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Message: 1
Date: Fri, 27 Mar 2009 10:09:23 -0700
From: David Wise <David_Wise at Phoenix.com>
Subject: Re: [R-390] SERIAL 163 FOLLOW UP
To: "r-390 at mailman.qth.net" <r-390 at mailman.qth.net>
Message-ID:
    <339D67D3FFE9984AADF43212D53D0ED80E29140256 at hil-exch2k7.phoenix.com>
Content-Type: text/plain; charset="us-ascii"

This should remind us all to TAG OUR MODS.

Guilty,
Dave Wise

Motorola 363-PH-54 S/N 1014
- Adjustable PTO Tempco
- Add F103
- Carrier Zero Redesign
- Inrush Limiter
- 3DW7
- AGC Clamp
- Moment Of Silence

-----Original Message-----
From: r-390-bounces at mailman.qth.net [mailto:r-390-bounces at mailman.qth.net] On Behalf Of RICHARD MC KINNEY
Sent: Friday, March 27, 2009 9:36 AM
To: r-390 at mailman.qth.net
Subject: [R-390] SERIAL 163 FOLLOW UP

Thanks to this forum my R390A is now working on am and cw/ssb.  Yesterday I sat down and drew up a schematic of my bfo circuit and could see there is no way the 6BA6 that it came with in that socket would work.  I was up against a brick wall.  Then thanks to this forum I looked up the product detector mod and there was that schematic I drew up but it had a 6BE6 tube.  I put in a 6BE6 and off she went working fine.  I don't intend to remove the mod now but I do see a bunch of the old caps that need changed.  Someone sure did a factory looking job on the mod and it REALLY had me fooled.
  I was in the Air Force in the 60's as a radio repairman.  I was WN7DGD in my barracks with a homebrew Tx and a Knight R 100.  On week ends I would haul an R390A up to my room and operate.  What a great rig.  Now I'm proud to have one and will work to get it in good shape.  So thanks to all that responded and helped me thru my problem.  74 Rich

------------------------------

Message: 2
Date: Fri, 27 Mar 2009 21:02:53 +0100
From: Pedro Del Valle <ea2ig.pvr at gmail.com>
Subject: Re: [R-390] SERIAL # 163
To: R-390 at mailman.qth.net
Message-ID:
    <8ee5f0630903271302p6dbbd774tfdde704fab9727e2 at mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1

I have two R-90A one EAC and the other a Capehart and a R-390 Collins. None
had a Relay.
But I remember of an article in an old HAM RADIO MAGAZINE With a
modification  using a 6BE6 in sustitution of the 6BA6, for a product
detector,  and a Relay to switch AM/SSB with the BFO ON/OFF swiitch.
Excuse my poor english. Hope is of help
Pedro EA2IG

2009/3/27 RICHARD MC KINNEY <pmcknney at bellsouth.net>

> DE WB4VFN Rich
>  I have a R390a Serial @ 163.  Problem is turning on the BFO looses all
> output.  Rx is ok all bands with BFO off.  I have a manual for thr R390a but
> I guess mine is an earlier model.  The BFO in mine is nothing like the
> schematic.  Mine has a small relay that is switched on by the BFO switch.  I
> don't think this is any kind of mod as it looks factory wired.  The BFO
> circuit is also very different then the schematic I have.   The rig was
> given to me and I would love to see it work again properly.  So far I've had
> to change the 17 mc crystal and a few tubes to hear it work again.  Anyone
> have a schematic with a relay in the BFO switch?  73 Rich
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------------------------------

Message: 3
Date: Sat, 28 Mar 2009 01:00:07 +0000 (UTC)
From: odyslim at comcast.net
Subject: [R-390] media vs soda blaster
To: r390 list <r-390 at mailman.qth.net>
Message-ID:
    <1533776958.377021238202007003.JavaMail.root at sz0106a.westchester.pa.mail.comcast.net>

Content-Type: text/plain; charset=utf-8

Hi Gang,

I going shopping tomorrow for some paint stripping gear.

Is there anyone on the list that has used media blasters
as well as the soda blasters? My reason for asking is I  have
no experience with either. I have only used the old sand blasters.
I want to strip paint from the front radio panels knobs and sides.

Which would be better? 

Media blaster with walnut shells or soda blaster?

Any input from experienced individuals?

Your advise greatly appreciated.

Regards, Scott W3CV

------------------------------

Message: 4
Date: Fri, 27 Mar 2009 20:36:43 -0700
From: "Chris Kepus" <ckepus at comcast.net>
Subject: Re: [R-390] media vs soda blaster
To: <odyslim at comcast.net>,    "'r390 list'" <r-390 at mailman.qth.net>
Message-ID: <5670BF2BD45C464E888C13CE50750FFA at compmom>
Content-Type: text/plain;    charset="us-ascii"

Scott,

Soda blasters are great because soda does not damage the metal as it strips
the paint, nor does it damage rubber or plastic moldings.  However, soda
blasting does not remove rust.

Abrasive blast systems using aluminum oxide, glass bead, etc., are great
because they can give you a paint ready finish fairly quickly and various
media grades are available (less or more aggressive) depending on your
project.

You need to hit Google and read up on the subject.  One easy read that may
help you is "Abrasive Blasting vs. Soda Blasting For Paint Stripping" at
this site: 

http://www.eastwoodco.com/jump.jsp?itemID=1493&itemType=CATEGORY&path=1%2C3%
2C688%2C1319&KickerID=490&KICKER

73 and have a blast!  
Chris
W7JPG

"Good Strippers have more fun!"

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End of R-390 Digest, Vol 59, Issue 33
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