[R-390] RE: R-390 Digest, Vol 20, Issue 69
Craig Anderson Ext 1365
Craig.Anderson at saintpaul.edu
Tue Jan 3 08:15:37 EST 2006
Hardware kits
You can get all the stainless hardware for the front panel including the
correct conical washers from McMaster Carr on the web.
Craig W9CLA
-----Original Message-----
From: r-390-bounces at mailman.qth.net
[mailto:r-390-bounces at mailman.qth.net] On Behalf Of
r-390-request at mailman.qth.net
Sent: Friday, December 30, 2005 8:07 PM
To: r-390 at mailman.qth.net
Subject: R-390 Digest, Vol 20, Issue 69
Send R-390 mailing list submissions to
r-390 at mailman.qth.net
To subscribe or unsubscribe via the World Wide Web, visit
http://mailman.qth.net/mailman/listinfo/r-390
or, via email, send a message with subject or body 'help' to
r-390-request at mailman.qth.net
You can reach the person managing the list at
r-390-owner at mailman.qth.net
When replying, please edit your Subject line so it is more specific
than "Re: Contents of R-390 digest..."
Today's Topics:
1. Re: Trim Caps on Mechanical Filters (Tim Shoppa)
2. Re: Another glaringly obvious 390A question for
thehypothetical newbie (Cecil Acuff)
3. Straight Key Night (Don Reaves)
4. Re: Another glaringly obvious 390A question for
thehypothetical newbie (Tim Shoppa)
5. Re: Another glaringly obvious 390A question
forthehypothetical newbie (Barry)
6. Y2K CD? No Jeff Adams CD? Yes (Was "Index for Drawings Files
on Y2K CD") (Tom Norris)
7. Re: Another glaringly obvious 390A question for
thehypothetical newbie (Tom Norris)
8. Re: Trim Caps on Mechanical Filters (Flowertime01 at wmconnect.com)
9. Re: Trim Caps on Mechanical Filters (Tim Shoppa)
----------------------------------------------------------------------
Message: 1
Date: Fri, 30 Dec 2005 08:39:34 -0500
From: shoppa_r390a at trailing-edge.com (Tim Shoppa)
Subject: Re: [R-390] Trim Caps on Mechanical Filters
To: R-390 at mailman.qth.net, Flowertime01 at wmconnect.com
Message-ID: <20051230133934.B32B2BA480D at mini-me.trailing-edge.com>
Content-Type: text/plain; charset=us-ascii
Flowertime01 at wmconnect.com wrote:
> I think if we look at decks with and without trimmers on the bottom
side, we
> will see that the decks have a lot of differences to allow the caps to
be
> inserted. There was just not a big blank chassis wall space there
waiting for
> additional caps.
Actually, there was a big blank chassis wall space. I've got right in
front of me an early no-trimmer Collins IF deck and a with-trimmer EAC
IF deck. I do see some changes in components (they were built more than
a decade apart after all) and wiring between the
two, and a significant improvement in sheet metal in the EAC (which
has bossed in nut threads on the shield between the last two IF
switch wafers, while the Collins has a nut and a washer). But if the
holes were put in the outer wall and the little trimmer board were
added, there are absolutely no physical constraints to putting them
into the old Collins.
Overall the much later EAC has sheet metal work that looks spiffier
and done with fewer pieces and joints and nuts and bolts. Mounting
of grounding lugs etc. differs in a few ways from the Collins as a
result but I can see that the EAC layout is more highly evolved.
I do feel that the trimmer tree at the top of a trimmer-cap IF filter
box
looks ungainly and fragile, but they did it anyway... On one of
my trimmer IF decks it looks like a trimmer cap broke off the tree and
was glyptol'ed back on.
Tim.
------------------------------
Message: 2
Date: Fri, 30 Dec 2005 09:48:28 -0600
From: "Cecil Acuff" <chacuff at cableone.net>
Subject: Re: [R-390] Another glaringly obvious 390A question for
thehypothetical newbie
To: <r-390 at mailman.qth.net>, "Tom Norris" <r390a at bellsouth.net>
Message-ID: <004401c60d58$7a990690$6401a8c0 at acuff1>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=response
I'd give him Walter Wilsons Email address and have him order a hardware
kit.
It comes with all the stainless hardware you see on the front panel. I
don't
think you can go just anywhere and buy the conical lock washers.
Elsewhere
in the radio standard stainless hardware available at any good hardware
store should be fine...a lot of it is stuff like 6-32 or 8-32 sizes if I
remember correctly...
Cecil....
----- Original Message -----
From: "Tom Norris" <r390a at bellsouth.net>
To: <r-390 at mailman.qth.net>
Sent: Thursday, December 29, 2005 11:54 PM
Subject: [R-390] Another glaringly obvious 390A question for
thehypothetical
newbie
>A newbie, all aglow from receiving his first ever R-390A from Ebay but
>wanting to find something to replace the rusted screws in the front
panel
>of his new radio emails the list and asks --
>
> "Is there a list of the sizes of hardware used on this radio? I need
to
> replace the rusty ones on my front panel, and several other screws
around
> the radio are missing too."
>
> Where would you send him for a list that has a breakdown of what
sizes of
> screws are used where on the front panel, and what are the common
sizes
> used elsewhere?
>
> I'm asking this from a person's view who has never seen one of these
> radios before, and while probably has a manual on the way it hasn't
> arrived yet.
>
> Myself I keep a well-labeled assortment.
>
> Tom NU4G
> _____________________________________________________________
> R-390 mailing list
> Home: http://mailman.qth.net/mailman/listinfo/r-390
> Help: http://mailman.qth.net/faq.htm
> Post: mailto:R-390 at mailman.qth.net
> Unsubscribe: http://mailman.qth.net/mailman/options/r-390
>
------------------------------
Message: 3
Date: Fri, 30 Dec 2005 09:57:54 -0600
From: "Don Reaves" <don at reatek.com>
Subject: [R-390] Straight Key Night
To: <R-390 at mailman.qth.net>
Message-ID: <002b01c60d59$cdaa5360$6400a8c0 at DELL1>
Content-Type: text/plain; charset="us-ascii"
If this year's Straight Key Night is like last, here is a chance to
exercise
your R-390A narrow CW filters. Lots of crowded, slow speed signals
bunched
up in the bottom half of the 80,40,20 meter ham bands. Many of the
signals
you hear will be rarely used vintage transmitters, so there is a
challenge
to twist knobs and track the chirpers and drifters and weak sigs. Just
what
R-390 receivers were born to do...
New Year's Eve 7pm EST to New Year's Day 7pm EST.
Details at
http://www.arrl.org/contests/rules/2006/skn.html
Hope to work some of you. Happy New Year
W5OR
don at reatek.com
w5or at comcast.net
> -----Original Message-----
> From: r-390-bounces at mailman.qth.net
> [mailto:r-390-bounces at mailman.qth.net] On Behalf Of
> Flowertime01 at wmconnect.com
> Sent: Thursday, December 29, 2005 7:22 PM
> To: R-390 at mailman.qth.net
> Subject: Re: [R-390] Trim Caps on Mechanical Filters
>
> DW Holtman ask,
>
> Was the modification that installed variable caps (C-569
> through C-571) in
> the input and output of the mechanical filters in the If
> module applied at Depot
> during rebuilds, or just put on newly manufactured modules?
>
> There are two flavors of mechanical filter caps in production.
> What you see is what you get. The field never went back and
> "upgraded" the
> caps in the IF deck.
>
> Early production had selected fixed caps.
>
> Later production had 4 caps under the can and 4 more on the
> side of the deck.
> These units also had 4 more holes in the side of the frame to
> access the side
> caps.
>
> If you have an IF deck with side caps and no side holes in
> your frame, you
> have a swapped in IF deck. Conversely if you have holes in
> the frame and no caps
> you have a swapped out IF deck. This will start some chatter
> and likely get
> us another dead carcass. So near the new year and such tasks
> to be dealt with.
>
> There was much todo about what to do if you had to replace a
> mechanical
> filter in a deck that did not have trim caps. The last word
> in 1975 as I was
> getting out of service was still to just put the filter in
> and ignore the cap
> optimization problems. Wisdom from management powers was that
> once the caps were
> properly trimmed they needed no further adjustment. If you
> measured the output
> before you tweaked on the trim caps, you likely found your
> diddling produced no
> further gain. Experience in the field did not support this
> wisdom from higher
> management. It was standard procedure to tweak all the filter
> trim caps on
> every PM event. We wondered why there was no modification
> work order to at least
> add the top caps to the IF decks. We could see why no one
> wanted us drilling
> into IF deck and installing caps in the bottom side.
>
> I think if we look at decks with and without trimmers on the
> bottom side, we
> will see that the decks have a lot of differences to allow
> the caps to be
> inserted. There was just not a big blank chassis wall space
> there waiting for
> additional caps. The extent of these changes may have been
> why no field
> modification was ever kited and fielded. The idea of
> providing new decks with caps was
> just a non starter from spending and contract point of view.
> Letting someone
> drill holes in the frame to trim decks in place was not a
> popular subject.
>
> We always wondered how much better a deck would have been if
> it had had
> adjustable caps. Decks without trimmers still passed signal
> to noise test like
> every other receiver, so we believed the assembly folks did a
> good job testing and
> selecting the fixed caps.
>
> One myth was the early production was "selected" to closer
> specification.
> Once Collins had a big pile of good but not good enough
> filters, a proposal was
> produced and sold to get the trim caps in and the less exact
> filters in. Myth
> was that a well trimmed deck never needed adjustment. I have
> no evidence to
> support that statement.
>
> Hope this provides you some insight on the subject.
>
> Roger AI4NI
> _____________________________________________________________
> R-390 mailing list
> Home: http://mailman.qth.net/mailman/listinfo/r-390
> Help: http://mailman.qth.net/faq.htm
> Post: mailto:R-390 at mailman.qth.net
> Unsubscribe: http://mailman.qth.net/mailman/options/r-390
>
>
------------------------------
Message: 4
Date: Fri, 30 Dec 2005 15:38:21 -0500
From: shoppa_r390a at trailing-edge.com (Tim Shoppa)
Subject: Re: [R-390] Another glaringly obvious 390A question for
thehypothetical newbie
To: r390a at bellsouth.net, r-390 at mailman.qth.net, chacuff at cableone.net
Message-ID: <20051230203821.C5738BA47E0 at mini-me.trailing-edge.com>
Content-Type: text/plain; charset=us-ascii
"Cecil Acuff" <chacuff at cableone.net> wrote:
> I don't think you can go just anywhere and buy the conical lock
washers.
I've had very good luck with flat external tooth lockwashers. Just
screw them down until they become conical...!
> Elsewhere
> in the radio standard stainless hardware available at any good
hardware
> store should be fine...a lot of it is stuff like 6-32 or 8-32 sizes if
I
> remember correctly...
And a certain amount of 4-40's and 2-56's as well if you're getting
down to the component level (as opposed to simply removing
subassemblies).
I've heard rumor that the spline set screws are 8-36, but I've never
run across that thread elsewhere to check!
Tim.
------------------------------
Message: 5
Date: Fri, 30 Dec 2005 17:37:48 -0600
From: "Barry" <N4BUQ at aol.com>
Subject: Re: [R-390] Another glaringly obvious 390A question
forthehypothetical newbie
To: <r-390 at mailman.qth.net>
Message-ID: <000c01c60d9a$120e75a0$3ca78aac at scott>
Content-Type: text/plain; charset="iso-8859-1"
Yes, they're #8-36 threads. I have a tap I use to clean the threads out
after coating the knobs.
Barry - N4BUQ
> I've heard rumor that the spline set screws are 8-36, but I've never
> run across that thread elsewhere to check!
>
> Tim.
> _____________________________________________________________
> R-390 mailing list
> Home: http://mailman.qth.net/mailman/listinfo/r-390
> Help: http://mailman.qth.net/faq.htm
> Post: mailto:R-390 at mailman.qth.net
> Unsubscribe: http://mailman.qth.net/mailman/options/r-390
>
------------------------------
Message: 6
Date: Fri, 30 Dec 2005 18:06:40 -0600
From: Tom Norris <r390a at bellsouth.net>
Subject: [R-390] Y2K CD? No Jeff Adams CD? Yes (Was "Index for
Drawings Files on Y2K CD")
To: r-390 at mailman.qth.net
Message-ID: <8F0C96D9-6AA0-49F3-BDF6-95279CA4C09D at bellsouth.net>
Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed
For reasons unknown I had gotten the Y2K manual mixed in with
my directory containing Jeff Adam's Big CD o' Manuals and Drawings
that was published a while back.
I had also backed them up as one volume, so that is where the
confusion began....
The mechanical drawings to which I was referring are on Jeff's CD.
That CD contained a dos/windows based reader with a file indexer
that was - to me - a fairly clunky affair. Now it's not usable, not sure
how many others are having the same problem, it may just be me. In
my previous post I indicated I can read the files with no problem, but
I'm limited to reading them randomly at the moment.
Thanks for an earlier reply regarding the possiblilty of an Exel index.
Tom NU4G
On Dec 29, 2005, at 7:46 PM, Barry Hauser wrote:
> Hi Tom
>
> Y2K CD??
>
> I don't think there ever was one. Al may have authorized someone
> to include
> it on a CD of other files, but I don't think so.
>
> What CD is that?
>
> Barry
>
>
>
>
> ----- Original Message -----
> From: "Tom Norris" <r390a at bellsouth.net>
> To: <r-390 at mailman.qth.net>
> Sent: Thursday, December 29, 2005 8:29 PM
> Subject: [R-390] Index for Drawings Files on Y2K CD
>
>
>
>> Is there a "flat" index for the engineering drawings on the Y2K CD?
>> I've forgotten from when I've used it with windows if there was one.
>> Now that I'm on a Mac and am interested in accessing them, they
>> appear to be spread out over several directories in several places.
>> Any help appreciated.
>>
>> thanks
>>
>> Tom NU4G
------------------------------
Message: 7
Date: Fri, 30 Dec 2005 19:27:52 -0600
From: Tom Norris <r390a at bellsouth.net>
Subject: Re: [R-390] Another glaringly obvious 390A question for
thehypothetical newbie
To: r-390 at mailman.qth.net
Message-ID: <DFF4A710-FE0C-4986-9EF7-AF18724818D0 at bellsouth.net>
Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed
Well, if we're going to get that detailed, let's not forget the roll-
pins that the ends of the cam shafts on!! I didn't measure than at
the time, and I can't find the drivers I used so I dunno the size.
It's a possible repair.
#2-56? Where are those? They're nearly the size of those pins I had
to drive out! heehee
I know there 4-40's in there.
Tom
On Dec 30, 2005, at 2:38 PM, Tim Shoppa wrote:
>
> And a certain amount of 4-40's and 2-56's as well if you're getting
> down to the component level (as opposed to simply removing
> subassemblies).
>
> I've heard rumor that the spline set screws are 8-36, but I've never
> run across that thread elsewhere to check!
>
> Tim.
>
------------------------------
Message: 8
Date: Fri, 30 Dec 2005 20:44:32 EST
From: Flowertime01 at wmconnect.com
Subject: Re: [R-390] Trim Caps on Mechanical Filters
To: R-390 at mailman.qth.net
Message-ID: <2bf.2987517.30e73c80 at wmconnect.com>
Content-Type: text/plain; charset="US-ASCII"
Tim,
OK so now you have looked under the two different types of IF decks and
find
ample space to place four trimmer caps.
Before the end of 2006 as a new year resolution please provide the R390
reflector here a very concise write up equal to a field modification
procedure.
Exactly detail how to modify the non cap chassis to a cap chassis.
Please provide
a detail list of parts. Please provide mechanical drawings such that the
mechanical mounting parts can be fabricated from the drawing to provide
some of
the parts to make up the complete parts kit. Please include in the field
kit
installation, a template for drilling the side of the receiver frame.
You get the
parts list and detailed instructions and I know we can find the parts to
do
kits.
I write that prior to 1975 the military looked at the problem a couple
times
and chose not to spend the money on it. Your response is there is room
on the
deck to do it. If that was the only item I am sure the military would
have
done it. Because I said there was not room on the chassis and you think
there is
room every thing else I posted is mostly not credible. You rate eight
good
years of my life as fiction. I try to write this really boring trivia
with some
humor. Some Fellows today wonder what the engineers in the past were
thinking
and why they made the choices that were made. I call these choices
compromises.
I find most are motivated by return on investment. How much bang do we
get
for the buck? There is value to be taken away from these questions and
answers.
>From these questions and answers I take way a lot of humor and get much
practice with my typing and writeing skills. I am sorry it falls on you
to grade my
work. A boring job but some one has to do it. I do try to keep it on the
R390
subject while varied. While most days I do enjoy taking a cut at
providing
some insight and sharing what I saw go down in my life, I am sorry my
post are
not up to your exacting critical reading expectations. I believe if I
had more
writing skills, I could have been a good author and would not have had
to make
a living prior to my retirement at age 55, assembling auto engines,
repairing
radios, being an electrician, and a computer scientist. I will continue
to
share my response to questions here on the R390 reflector and try not to
worry as
much.
Here's your chance. I bet lots of fellows own R390/A decks without the
variable caps and would like to have the write up to make the
modification. It sure
would be a very nice addition to the R390 resources.
I am looking forward to your work and the chance to modify one of my
decks
from your wonderful work. While the military considered and rejected the
idea
having the IF decks field modified, that would not stop some R390/A
owners from
taking on the task and doing it very successfully. Many Fellows have
many more
resources today for doing the task than were available back it the old
days.
How about the can on top, Will it need to change size or can we squeeze
every
thing in the original can?
How much improvement will we get in the signal to noise ratio?
How will the band pass be effected?
What gain will one get for the pain?
Just because one can make the change should we make the change?
Roger
------------------------------
Message: 9
Date: Fri, 30 Dec 2005 21:04:46 -0500
From: shoppa_r390a at trailing-edge.com (Tim Shoppa)
Subject: Re: [R-390] Trim Caps on Mechanical Filters
To: R-390 at mailman.qth.net, Flowertime01 at wmconnect.com
Message-ID: <20051231020446.C3AE2BA480A at mini-me.trailing-edge.com>
Content-Type: text/plain; charset=us-ascii
Flowertime01 at wmconnect.com wrote:
> OK so now you have looked under the two different types of IF decks
and find
> ample space to place four trimmer caps.
>
> Before the end of 2006 as a new year resolution please provide the
R390
> reflector here a very concise write up equal to a field modification
procedure.
> Exactly detail how to modify the non cap chassis to a cap chassis.
Please provide
> a detail list of parts. Please provide mechanical drawings such that
the
> mechanical mounting parts can be fabricated from the drawing to
provide some of
> the parts to make up the complete parts kit. Please include in the
field kit
> installation, a template for drilling the side of the receiver frame.
You get the
> parts list and detailed instructions and I know we can find the parts
to do
> kits.
> Just because one can make the change should we make the change?
Wow, Roger, didn't mean to tick you off.
I enjoy questions that are easily answered by looking under the covers,
poking around with ohmmeters and voltmeters and signal generators,
and comparing/contrasting small technical details.
So if you say "it wasn't done for reason X", I read what you write
with enough interest to go look and see reason X for myself. Don't
take that as a mistrust of your facts, but take it as me being
interested in what you write about.
If I misinterpret your intended-to-be-factually-incorrect-for-humorous-
intent statements as being actual mistakes, I apologize.
I do seem to have rubbed you the wrong way a couple times in the past
couple of weeks, putting me in the "bad guy" column way more than
anyone else on this list. Who knows, maybe I'll get kicked off the
list the next time I look under the covers of my R-390A instead
of trusting the word of a respected poster.
Tim.
------------------------------
_______________________________________________
R-390 mailing list
R-390 at mailman.qth.net
http://mailman.qth.net/mailman/listinfo/r-390
End of R-390 Digest, Vol 20, Issue 69
*************************************
More information about the R-390
mailing list