Someone is offering to sell me a Collins 51S-1 general coverage receiver, a
"winged emblem" model.

I'd be interested to hear how people would compare it to similar-quality
receivers. I can read the specs in the Osterman book, but what is it really
like to use, and how does it stack up against others? Any quirks, PITA
characteristics, standout features, etc.?

And, assuming it's in average condition, what would be a fair price?

Regards,

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

Phil, Having been through several 51S-1's and S-1A's (still have one),
I'd say the going would be $500-$1200 depending on condition. Is it in
a case or is is a rack mount job? How well does the PTO track and
what's the condition of the crystals (can you calibrate each band and
band edge? Changing an out-of-spec crystal can be a noteworthy
mechanical challenge. As far as operations go, its a fairly decent
receiver. I think that a similar condition R-390A would be a better way
to go, but maybe physical size of of concern? Parts are quite scarce,
should any be needed in the future. But, if the unit you're being
offered is clean, up to spec, and you're a Collins aficionado, there are
far worse things you could do with your money....hi!

Phil Nelson wrote:
Someone is offering to sell me a Collins 51S-1 general coverage receiver, a
"winged emblem" model.

I'd be interested to hear how people would compare it to similar-quality
receivers. I can read the specs in the Osterman book, but what is it really
like to use, and how does it stack up against others? Any quirks, PITA
characteristics, standout features, etc.?

And, assuming it's in average condition, what would be a fair price?

Regards,

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

Phil,

(The last time I played with one was about 20 years ago). It's a
state-of-the-art 1960s-era _communications_ receiver for SSB, CW and the
kind of intentionally bandwidth-limited AM used for communications years
ago. As I recall, it was a lot more expensive than the similar Collins
amateur radio receivers, but some hams liked to have SWL capabilities
(as I did). I believe the main customers were the military, embassies
and commercial point-to-point communications stations. Its definitely a
lot easier to tune than an R-390, the dial is very smooth and nice.

For MW or SW broadcast listening, you can tell that the AM bandwidth is
limited, and, at least for me, the fact that the tuning is broken up
into 1 MHz bands, is a bit of a nuisance. Also, below about 2 MHz, it
can really use the matching preselector to give it more gain (the lower
bands are upconverted).

I'm not sure about serviceability, but Collins equipment can be tricky
to work on. Somewhere I read that some people refurbishing these
receivers have replaced some of the local-oscillator crystals, and
perhaps the calibrator crystal to make the calibration more accurate.
Not sure about other components that tend to go bad.

I've seen a 51S-1 offered for $1100.00 this year -- according to another
listing the used price is in the $1100.00 -$2100.00 range.

Northe,
N6KO



Phil Nelson wrote:
Someone is offering to sell me a Collins 51S-1 general coverage receiver, a
"winged emblem" model.

I'd be interested to hear how people would compare it to similar-quality
receivers. I can read the specs in the Osterman book, but what is it really
like to use, and how does it stack up against others? Any quirks, PITA
characteristics, standout features, etc.?

And, assuming it's in average condition, what would be a fair price?

Regards,

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

K3HVG wrote:
Phil, Having been through several 51S-1's and S-1A's (still have one),
I'd say the going would be $500-$1200 depending on condition. Is it in
a case or is is a rack mount job? How well does the PTO track and
what's the condition of the crystals (can you calibrate each band and
band edge? Changing an out-of-spec crystal can be a noteworthy
mechanical challenge. As far as operations go, its a fairly decent
receiver. I think that a similar condition R-390A would be a better way
to go, but maybe physical size of of concern? Parts are quite scarce,
should any be needed in the future. But, if the unit you're being
offered is clean, up to spec, and you're a Collins aficionado, there are
far worse things you could do with your money....hi!

Many years ago, I traded my 51S for an R-390A, and it was a weird sort
of step.

For pulling SSB and CW out of the muck, the R-390A beats the 51S hands down,
so many different ways it's not funny. Signals you never thought you'd
be able to copy really pop out with the mechanical filters on the R-390.

But the audio on the 51S beats the audio on the R-390 hands down, also.
If you want to listen to AM shortwave broadcasts or join the 40M AM
crowd, and you care about weak signal performance but not about the
ultimate in selectivity, the 51S is a pretty fine receiver and I'd pick
it over the R-390.

I miss mine sometimes, especially for MW DXing.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Scott Dorsey wrote:


But the audio on the 51S beats the audio on the R-390 hands down, also.
If you want to listen to AM shortwave broadcasts or join the 40M AM
crowd, and you care about weak signal performance but not about the
ultimate in selectivity, the 51S is a pretty fine receiver and I'd pick
it over the R-390.

That's why Sherry has the best of both worlds - an R-391 with a 390A IF
- which can be swapped out with it's original 390/1 deck in few seconds.
The /A IF is great for copying RTTY - the original IF is much better for
cruising the bands. It's an option anyone with either radio (non and /A)
can do...

best regards...
--
randy guttery

A Tender Tale - a page dedicated to those Ships and Crews
so vital to the United States Silent Service:
http://tendertale.com

Hi,

I bought a used 51S-1 about 15 years ago,
and it arrived with a burned-out antenna coil
for the 7 mc band (strange that the seller didn't notice that...)

All of the band change components are mounted on fiberglass
sections of a ten-section turret switch. To get at the parts
for repair, one must first remove the shaft of the switch,
and then the individual switch sections can be removed.
I'm mechanically somewhat ham-handed, but I managed it OK.

The 51S-1 seems a bit more stable than the 75S-3C,
I think because the PTO is not switched
to maintain dial calibration for USB/LSB operation.
Instead, there are two separate mechanical filters for USB
and LSB, and the BFO itself stays crystal controlled right at 500 kc.
The sideband mechanical filters are broad, about 2.8 kc,
and the c.w. crystal filter is 800 cycles bandwidth
(no variable BFO is included).
A.M. reception is via standard IF transformers,
with only about 5 kc bandwidth.
Collins offered an optional 6 kc mechanical filter for A.M.
They also offered optional 2.4 kc SSB mechanical filters,
and a 300 cycle c.w. filter.

The agc action is not that great, and the S/meter drifts a lot
in my unit - one of these days I'll get annoyed enough to track
down the source of the S/Meter drift. (+not+ caused by gassy
if/rf amplifier tubes).

Below 2 mc, the receiver is deaf without the (very scarce) 55G-1
low frequecy preselector.
Audio quality is pretty decent, and SSB is very
pleasant listening, if QRM is not a problem due to the bandwidth.

Selectivity before the first mixer is outstanding, based on the use
of double-tuned LC circuits before the rf amplifier.
If you connect the receiver to a random wire antenna,
you may be disappointed, because the receiver
really needs a 50 Ohm antenna system due to its front end filtering.
On occasion, I've used an E.F. Johnson TR switch between a random piece
of wire and the receiver input (it acts as a cathode follower
with 50 Ohm output), and the set-up worked very well.

The main tuning knob turns freely, so it is a good band cruiser.
There is a bit of clackity-clack audio noise while you tune away,
due to the turns counter which keeps track of which part
of the 1 mc band you are tuned to.
The PTO dial is marked in 1 kc increments from 0 to 100 kc,
and the counter display may be read 07.2 mc.
The tuning rate is about 30 kc per revolution.

In summary, the 51S-1 is a more than competant receiver,
with no really flashy features.
It doesn't give the operator much flexibility -
no variable BFO, no choice of SSB bandwtdths, AGC fast/slow, etc.,
so a knob-twister like me has nothing to do but listen
to the other ham (a daunting prospect!).

73,
Ed Knobloch

Phil Nelson wrote:
Someone is offering to sell me a Collins 51S-1 general coverage receiver, a
"winged emblem" model.

I'd be interested to hear how people would compare it to similar-quality
receivers. I can read the specs in the Osterman book, but what is it really
like to use, and how does it stack up against others? Any quirks, PITA
characteristics, standout features, etc.?

Phil Nelson wrote:
Someone is offering to sell me a Collins 51S-1 general coverage receiver, a
"winged emblem" model.

I'd be interested to hear how people would compare it to similar-quality
receivers. I can read the specs in the Osterman book, but what is it really
like to use, and how does it stack up against others? Any quirks, PITA
characteristics, standout features, etc.?


Phil,

The engineering and construction of this unit is quite unlike anything
you currently possess. It uses a crystal controlled, permeably-tuned
front end for tuning, which makes for a VERY stable receiver and a dial
that is deadly accurate. This is one of those things where the
mechanical engineering is every bit as marvelous as the electronics. The
quality of everything is really first-rate.

PITA factor is pretty high on this, as it is on most Collins gear. The
complexity is daunting if you have not dealt with one of these before.
You will need to check all the crystals and replace at least some of
them, as they age and drift a bit off-frequency over the years. In
extreme cases, a turn may need to be taken off the oscillator coil
because it changes characteristics as it ages as well. The resistors
will all have to be checked and the the out-of-tolerance ones replaced.
The audio output tube is run VERY hot on this rig-in fact, it is running
about 20% above its absolute maximum rating! Some people like to modify
the output circuitry to bring it down-to-earth a bit.

All that being said, this is an outstanding receiver. If you can get it
for a good price, it is worth it just for the experience of owning one.

-Scott

Thanks for all of the feedback. I have passed along the lead to a pal who
knows some people who may be more interested than I am.

Phil Nelson

Someone is offering to sell me a Collins 51S-1 general coverage receiver,
a "winged emblem" model.

I'd be interested to hear how people would compare it to similar-quality