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Old December 7th 09, 11:10 PM posted to rec.radio.amateur.boatanchors
Richard Knoppow Richard Knoppow is offline
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First recorded activity by RadioBanter: Oct 2006
Posts: 527
Default Collins 651S-1 Question - Retaining Frequency


"Jeff" wrote in message
...
On Dec 6, 2:36 pm, Dave Heil wrote:
WA4VZQ wrote:
Jeff, N6NMI, wrote in message
news:ce12ab6a
...
Is there a 651S-1 mod that retains the last listening
frequency when
the radio is turned off? Now I get ".0000" each time I
turn the radio
on, regardless of what frequency I was tuned to when I
turned it off.
A youtube video shows the radio coming up tuned to 20
meters when it
is turned on: how is this implemented?


I added a 6 VDC source to the terminal strip on the
back, and that
retains the frequency when I unplug the radio, but when
I turn it off
using the power switch it still comes up .0000 when I
next turn it on.


From the
website,http://www.collinsmuseum.com/651s1.html:


"FREQUENCY MEMORY KEEP-ALIVE POWER
Used to maintain storage of frequency information during
power
interruptions. An external 6- to 8-volt battery supplies
the necessary
power for the circuit. This option is implemented by
wiring the special
keep-alive assembly into the chassis subassembly. Refer
to the
configuration chart for status numbers of receivers that
include this
option and for the part number of the chassis
subassembly that includes
the special keep-alive power assembly."


That's the skinny. We used a rack of four of them at the
U.S. Embassy
in Guinea-Bissau in 1987-89. Each had been modified by
having its blue
fluorescent displays replaced with LEDs. The receivers
each had had a
6-volt gel cell. All the gear was replaced by Harris
equipment shortly
after I left in September, 1989 and was replaced by Harris
equipment.- Hide quoted text -

- Show quoted text -


Hmmm; so with the 6 VDC source connected, when I turn off
the power
switch, and turn in back on, I should see the same frequency
displayed
as when I turned it off? I'm not seeing this behavior with
my radio;
if I unplug the power cord from the wall, and plug it back
in, this is
the way it works, but if I cycle the power using the panel
mounted
switch, I get ".0000".

I am not at all familiar with this receiver but is it
possible that the power switch is also a reset switch? If it
is perhaps its possible to disable the reset function.



--
Richard Knoppow
Los Angeles
WB6KBL