[ARC5] AN/ARC-5 R-23 Question

Tue Dec 26 19:41:46 EST 2023

Merry Christmas to all!

After locating and fixing a cold solder joint the R-23 lives!

I decided to try the radio without doing the cap replacement and it's
limping along – noisy and low sensitivity... not surprising.

I was able to hear RNB 368 barely tonight.   Afterwards I hooked up a
signal generator and the radio receives throughout it range.

Tomorrow I'll start the cap replacement.   I've done that on multiple
SCR-274N receivers and I've just removed the flower pots and installed new
caps (keeping the original pieces in bags.....).   I may try restuffing the
flower pots this time around.

I've a question on the HB local remote switch.   I believe the real cover
has a jack with the cover labeled CW-4 ??   This is what I've seen on web
pictures of other R-23 receivers,  yet Figure 6-2 of the previously
mentioned AN/ARC-5 manual seems to show a different connector MX-20/ARC-5
power adapter ?

[image: image.png]

73 Mark K3MSB

On Sat, Dec 23, 2023 at 9:23 PM Brian Clarke <brianclarke01 at optusnet.com.au>
wrote:

> Hello Mark,
>
>
>
> In the images of your R-23, five potted capacitors are leaking wax.
> Running at lower HT will not delay onset of problems; better to replace
> with post-WWII potted capacitors (rated for 400 V) where a different
> insulant was used that did not leak out. Many years ago, I published a
> technique for rebuilding potted capacitors with modern components. I’ll see
> if I can find it.
>
> Some Command receivers came from the factory wired for 12 to 14 Vdc for
> use in aircraft with 12 V system, such as the British A V Roe aircraft, the
> PBY, and, as I recall, the Harvard trainer. Such receivers had an ‘X’ added
> to the nomenclature plate. The DM-53AZ dynamotor was used instead of the
> DM-32. As I recall, the intercom audio change-over relays in the mounting
> racks worked OK on 12 V.
>
> PVC insulated wiring came late in WWII when DuPont sort of learned how to
> stablise PVC. Unfortunately, many years passed before true stablisation
> occurred. Post WWII, house mains wiring shifted from cotton covered,
> rubber-insulated cables to early PVC – now, that PVC is turning to mush
> giving a boon to electrical trades for rewiring houses.
>
> As I recall from reading the operating instructions, that capacitor (C-30)
> insulated from the chassis was for feeding audio through the front bucket
> connector to ground personnel guiding the aircraft to a parking area.
>
> If you seek 85 kHz IFTs, I can help.
>
>
>
> 73 de Brian, VK2GCE
>
>
>
>
>
> *From:* arc5-bounces at mailman.qth.net [mailto:arc5-bounces at mailman.qth.net]
> *On Behalf Of *Mark K3MSB
> *Sent:* Saturday, 23 December 2023 9:26 AM
> *To:* Mike Kana
> *Cc:* ARC5
> *Subject:* Re: [ARC5] AN/ARC-5 R-23 Question
>
>
>
> Hi Mike
>
>
>
> Yes, it sounds a lot like mine.   Photo attached.
>
>
>
> Mark K3MSB
>
>
>
> On Fri, Dec 22, 2023 at 12:15 AM Mike Kana <aa9il.radio at gmail.com> wrote:
>
> I have a similar R23 that had plastic coated wires added and a few
> remaining cloth wires. One flower pot cap has a black insulating base but
> the cap shell has a solder lug and a black wire (to ground?)
> The front had alameda NAS stenciled on the front and also a “test”
> identifier.
> It was partially modified when I got it - missing the dynamotor shock
> mounts and one of the if coils.
> I did replace a couple leaking flower pot caps in an effort to make
> operational.
> Does this sound similar to yours?
> Thx 73
> Mike
>
> Warning!  This is transmitted over a non secure medium
>
> > On Dec 21, 2023, at 8:30 PM, Mark K3MSB <mark.k3msb at gmail.com> wrote:
> >
> > 
> > Back in August I picked up an R-23 Navigation receiver.   I was
> delighted to find this as I do NDB hunting and wanted to play with this
> receiver on the LF band a bit this winter.
> >
> > Externally the radio was in nice shape with original connector on the
> back.   I removed the bottom cover and immediately saw modern wiring.  Lots
> of it.   Oh crud....
> >
> > The first thing I did was to check the filaments and, as expected, they
> were wired for 12/14 volts.  No problem there.
> >
> > The thing about the new wiring was that is was very nicely done, not
> your typical hack job you find in these radios.     I did some preliminary
> circuit tracing and it looks like some of the new wiring just replaced the
> old wires.
> >
> > I am using AN 16-30ARC-2 dated 15 Dec 1954 as my reference manual.   It
> is of course a copy from the web.
> >
> > I note in my R-23 that C-30 is insulated from the chassis, and the
> capacitor case goes through a 100K resistor to ground.
> >
> > In AN 1630ARC-2, Figure 6-3 (page 56) shows the underside of the radio.
>  It looks like C-30 is raised from the chassis – but since my manual is a
> copy,  all I see is black in that area.   Can any of you verify it is
> lifted / insulated from the chassis?
> >
> > Also, at the top of C-30 are 4 resistors (R4, R9, R11, and R-27).  My
> R-23 has a 5th resistor in that group, and that 5th resistor is the 100K
> that goes from the case of C-30 to ground.    The 5th resistor is original
> – It wasn't added later.
> >
> > My Figure 6-3 says it's of an early production set.  The schematics in
> the manual show the case of C-30 directly grounded, but I assume that is
> also for an early unit.  If any of  you have a different copy of the
> manual, can you check the schematic for this?
> >
> > Thank you & 73
> >
> > Mark K3MSB
> > ______________________________________________________________
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