[Premium-Rx] Re: Ten-Tec RX-340 ??

[AC7ZG]

Scott

Great experiment!  I don't know of any published specs on the lock of the
PLL used in the SAM circuits.

This is EXACTLY what real world use of the receivers can show you.

BTW I don't use the SAM on either receiver usually-- they lose lock on
really weak signals.
Instead I use SE-3's - you'll have to go to the webpage to read the specs
;-)
www.sherweng.com/indepth.html
Basically its a new product detector that claims to reinject a carrier (and
uses a PLL to do this). IT WORKS! <I really wish the 7800 could use an SE-3
but this is never going to happen>

Using the SE-3 with the receiver (choose wj, R590a, TT340, CUBIC, DrakeR7,
or the ultimate R-390A which pulls up even weaker signals than the WJs..but
is unwieldy to take to Grayland due to weight!...) and you'll pull out the
weak signals that others hear only as a het  or a really weak one in the
noise floor at Grayland.  There have been plenty of times when one of the
guys says "hey I got something really light on xxxkHz..." and I hand them
the headphones to listen to solid copy...

Glad you enjoy the thread. There is more to life than just specs....if that
was all I was interested in, I'd just buy the manuals and forget buying the
radios....who needs radios when you have the SPECS!!!  ;-) ;-)

By any chance were you also using your ham radio to listen in AM or SSB?
That'd be interesting as well (Guy Atkins has been modifying 746,
756pro/pro2 for weak signal TP MW dxing and has achieved some interesting
results.

Keep the real world experiments coming...

Best regards
Don

NOTE: I don't do much SWBC other than the few remaining weak signal tropical
stations. If I was doing SWBC, I much prefer the sound quality of one of the
NRD-535D's that were rebuilt by Craig at Kiwa. The sound is soooo much
richer than listening to the phase noise on any of the premium
receivers....the premium receivers were built for weak signal SigInt, not
armchair listening.
  -----Original Message-----
  From: premium-rx-bounces at ml.skirrow.org
[mailto:premium-rx-bounces at ml.skirrow.org]On Behalf Of Ka9p at aol.com
  Sent: Sunday, September 04, 2005 7:41 PM
  To: premium-rx at ml.skirrow.org
  Subject: [Premium-Rx] Re: Ten-Tec RX-340 ??


  I'm really enjoying reading this thread.

  Could someone maybe explain the likely basis for the difference in the SAM
performance between the HF1000A and RX-340?

  After reading the string of posts, since I had the two set up in a
comparison mode on the same antennas, I wandered away from the standard SWBC
fair I usually listen to (and I still don't think the 340 SAM is bad for
that) and looked around for some weak AM stuff, and settled in on the 75
meter DX-60 net this morning.  What I found kinda surprised me.

  The 340 required about 7 to 10 dbm above the noise level for SAM lock-up,
while  the WJ remained locked virtually all the time the carrier rose above
the noise.

  And as various weak AM stations came on, the WJ would take a few seconds
but lock on them when they were as much as 800 to 900 hertz high or low.
The 340 refused to lock on anything more than 300 hertz away.  The same
results were obtained on the 50 KW station on AM1000 about 1.5 miles from
here.

  Is this just a difference in algorithm, or is there something in the
overall design approach/philosophy that contributes to this much difference?

  And thanks for the link to the Grayland pictures  ("Honey, come look at
this, we're not so out of control here, are we ?" )

  Thanks for any enlightenment,

  Scott

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