[Premium-Rx] Sherwood SE-3

[Charles Hutton]

Hi Frank:

Mind saying a few words about your 56303EVM? Does it have an A/D that can
handle 455 KHz? And what about the SW it is running? Did you do a SW PLL? A
Costas Loop?


Chuck

-----Original Message-----
From: premium-rx-bounces at ml.skirrow.org
[mailto:premium-rx-bounces at ml.skirrow.org]On Behalf Of Carcia, Frank A.
HS
Sent: Friday, April 04, 2003 10:44 AM
To: 'Dan Neves'; premium-rx at ml.skirrow.org
Subject: RE: [Premium-Rx] Sherwood SE-3


Dan,
The RA6790, RA6830 and maybe some others have a MC1357 a FM demodulator
generating a LO to a MC1496 in AM mode so the effect is pretty much as the
SE3. It should help older receivers
like the R390. The only way to improve the Racals is to do an I/Q
demodulator off the 455 KHz IF and dump it into a DSP. I have a MOT
DSP56303EVM that out shines the Racal setup (a little bit) when the noise
level gets high. It might be because the brick wall filters in the software
though.   fc

-----Original Message-----
From: Dan Neves [mailto:NDan at heinze-institute.com]
Sent: Friday, April 04, 2003 1:35 PM
To: premium-rx at ml.skirrow.org
Subject: [Premium-Rx] Sherwood SE-3



	Hello everyone:

	Recently there has been a Sherwood SE-3 here in the shack and
perhaps a comments are in order. A couple of Racals are in use here with
the 455khz IF out required for the SE-3. I assume most of us know of
this item, it is an external phase locked detector that allows SSB and
PBT for AM only receivers and more...

	This item is new here, but what a bang up job this unit does
with the ra6217E. In back to back tests with the ra6790GM it gave little
up to the newer receiver in AM mode. The detector really shines here, at
least that is the experience here with this equipment. No wonder the
r-390 crowd is so hot on this item.

	With the receiver in SSB mode things change a little bit. The
ra6217E allows SSB with 3, 6, and even 20Khz filter bandwidths. With
this  ra6790GM the only SSB filter bandwidth is 3.2kHz. Here the biggest
performance advantage gain in SSB mode w/SE-3 goes to the older ra6217E
in SSB mode w/SE-3, and it remains a mystery as to why this is so. It
was assumed the SE-3 would be as good an asset to the ra690GM in this
regard. It was tried w/ and w/o AGC enabled on both units.

	The ra6790GM SSB mode is great for SWL DXing as it is. Very
little difference between the 2 it seems when ra6217E is in SSB mode w/
SE-3.

	The real question is how to obtain a similar performance gain
w/SE-3 with the ra6790GM. There is definitely a gain in AM detection and
signal stability and audio quality with this set-up, however not an
order of magnitude change as in the older Racal receiver. We will
continue this comparison for awhile.

	This item can make a heck of a difference, particularly in a
fading signal scenario, when the signal comes at you in waves. The SE-3
seems to really help out here in many cases.The audio tone and other
filters are really useful, not just add on switches, they are very
useful noise fighting and audio shaping.

	Needless to say this item stays put. Perhaps some luck is in
order for you fellows too, as this item came here from EBAY and cost
41.00 less Shipping.
The item is worth way more, particularly when it is realized that it
will will work from multiple receivers. Here it will be fed from a
switch that allows the IF out selection from either receiver. Also, the
output is fed into an audio mixer right now that allows the comparison
of the audio output of the receiver with and without the SE-3 in place.

	 Big difference on weak, fading signal performance for sure for
these older radios. Awesome choice for AM only ex-militaries with 455kHz
out.

	OK, if possible, if any folks out there have experience with
this item, please drop a note!

	Also, this is not meant to be a plug for Sherweng any more than
it is for Racal. This is stuff that is used here to good effect and it
makes me happy to say something out loud. Obviously Sherwood did not
make a dime off me in consideration of the auction location where the
item was purchased.

	Cordially, DanSeven



_______________________________________________

Premium-Rx Mailing List
To Post: premium-rx at ml.skirrow.org
For Info: http://ml.islandnet.com/mailman/listinfo/premium-rx

_______________________________________________

Premium-Rx Mailing List
To Post: premium-rx at ml.skirrow.org
For Info: http://ml.islandnet.com/mailman/listinfo/premium-rx