R-1051 Sensitivity S/N ISB vs AM

[N8ETQ]

 Hello All,



   Fasinating Radio... Just wondering if "2" x 3.5kc ISB
channels would yield a better S/N ratio than a 7kc YeahM BW.

       Dueling Product Detectors vs a 1N270 Diode...


"Sorry, I'm Drinking."

/Dan

[N8ETQ]

Thought this was interesting..Dated 10-May-2010..


1.1 USNS Big Horn has reported numerous failures of the R-1051 HF receivers and the availability of spares to affect repair is very limited. This work item will replace the ship's inventory of R-1051 HF receivers, (6) with R-2368 HF receivers recently appropriated from MSFSC decommissioned asset inventory


From:

https://www.fbo.gov/?s=opportunity&mode=form&id=1406ce17a90f13ed581aeb9272079a75&tab=core&_cview=0


   My personal 1051's arent much better. Can't comment about the S/N
thing yet.  I am amazed at how good these things have to be working
before you can figure out how broke they really are!

/Dan

"Slashing my wrists on the trailing edge of technology"

[WA1GFZ]

R2368 is a much better radio

[WB6NVH]

I would hope the 2368 (basically Harris 590) would be better, it's over 30 years newer, and the two are for completely different purposes anyway.

I had to laugh when I saw they want the contractor to refurbish and install their own surplus 2368's which have been screened from DRMO, and have probably been sitting outside in the weather for a few years.

I have never had much of any trouble with my 1051B's.  I bought a carload of them from a metal scrap merchant's dumpster for $ 40 each and they all came to life with just minor repairs needed.

Regarding ISB, the 1051 in that mode just turns on the left and right audio channels simultaneously with no mixing.  You can get it to sound OK on an  AM station but as soon as another station comes on which is just a bit off frequency, it sounds, well, bad...

[N8ETQ]

Yo', Yous,


   My point may have been the longevity of the 1051, I know there were
a lot of revisions, but technology marches on, and the plain old 1051 got
left in the dust.  Finally, after 30+ years.


Quote:

"Regarding ISB, the 1051 in that mode just turns on the left and right audio channels simultaneously with no mixing.  You can get it to sound OK on an  AM station but as soon as another station comes on which is just a bit off frequency, it sounds, well, bad..."

End Quote:

 

  Well, it does a bit more than that..


    Yeah, It's useless on the Ham Bands.  But with the DDS VFO's things
could get better.  "Beero Zeete" Net control.. HA HA Ha.

   If the Damn RF AGC was'nt wire "or'd" together It would be better, but you
have 2 SSB filters driving 2 seperate IF's both with "Nifty" AGC systems That are strapped together with a "Wire Nut" in ISB.

   Remenisant of the "what was I thinking" Syndrome !


Standby for a "Mary Lou  Reton"  moment"

 " And another thing"

Quote:

"I would hope the 2368 (basically Harris 590) would be better, it's over 30 years newer,"

End Quote.

  Yeah, My R-390 kicks butt over my SX-28 and it's not even 20 years newer.

     Anyway, It's a neat old RX with lots of MOD. potential, Too bad it's such
a PIA towork on.   If Murphys would have had R-590's for $150 ea.  Back
in '97 I would have bought a bunch of those. But Alas, It was not to be. I'm
not saying the 1051 is the best RX on earth, just that I want mine to be the
best they can. (Kinda like my Kids) .  I think my 1051's have the potential to
be the best RX's in my shack.  Simple test,  Set your "Vintage RX" to copy
USCG High Seas WX on 8764U or WLO on 4319U and see if not your runnin' for
the BFO Knob.

  No Flames Pal, just thoughts, as misguided as they may be.

73
/Dan

[N8ETQ]

Yo' Yous,


 I finally got this POS off the service bench and on to the operating
desk. What a "Freak Show".  Good to hear it through the station audio
system instead of the pair of LS-454's on the work bench.

  Station audio is R-1051 USB/LSB 600 ohm audio to my OLD "Crapco"
16X4X2 mixer to a Pioneer SX-950 Stereo RX to a pair of
JBL large studio monitors. Damn thing sounds great! 

  With my '63 Imperial R-390A "Panned" to "Stereo balance" off the
diode load, I gotta say, "I'm impressed" with the "Authority and
presence" of the output from the 1051. I'm not sure if the 600ohm
outputs from the 1051 are balanced or not, but I'm not cabled up for
it anyway. The "lightly" loaded audio amps seem to do a good job
passing a fairly flat audio bandwidth to the Tapco mixer. As does the
390's diode load. It  seem's to me that the AGC action's of the 1051
in ISB mode helps quite a bit with "fade distortion". Fades effects
the "Balance" but not the intellegibility. Locally generated carrier to
the product detectors is "sweet as long as its zero beat".

  The "RF" AGC from each sideband is wire OR'ed together but the "IF"
AGC's are independent on the 1051. Allegedly, I think it needs a couple
more diodes to ensure that. Anyway, I have line from the work bench to
the RX multi-coupler and need to do some "sweeping".


   Not sure this was worth the hassel but nice to hear the old rig
working well. I don't know why I'm so messed up on ISB, probably
because I can. The advantages are obvious, the implementation is daunting.
With the 1051 I'm thinking "Dual Synchronous Detectors" would handle
the "off frequency" scenerio so often encountered. My CV-157 handles that
well but it pulls 600W from the mains and takes a few seconds to
tune  unless one station is >600 hz off, then it too requires
manual intervention. I have a pair of HB synch. detectors on 455 kc
and could move them to 500 kc with little trouble.


  The entire preceeding paragraph could be simply summed up as:
"buy Anhieser-Bush stock now".


/Dan

[ke7trp]

Dan, I had one for a short while.  Once I realized that you need a stereo amp for the thing to work correctly. We sold it off.  Neat Rig, But not good for scanning the band. The chain Drive is neat.  The one I had would RX WWV on a small speaker wire ant.   

C