[Premium-Rx] WJ-8711A or WJ-8712P

Sat Jan 5 12:39:55 EST 2013

Please disregard the previous incomplete postings.

Regarding the relative performance of the WJ-8711 compared to the 
Racal RA3701 and the RA3791, about 15 years ago,I came across an 
internal report compiled at the 
Swedish Ministry of Foreign Affairs in the mid 90's.

They commissioned the Swedish Defence Radio Establishment to compare 
these receivers as part of an upcoming procurement and replacement 
project, 
as the SRT CR91 recently had been discontinued and the SRT operations 
had gone bankrupt for the first 
time.

The findings were that the RA3701 and 3791 "ran circles" around the 
WJ-8711,especially with regard to reciprocal mixing and 2-nd order 
IP.

Also the IP3 of the WJ-8711 was considered to be inadequate in the 
light of the 
Northern European HF signal levels.

For reasons unknown, the MFA receiver procurement was postponed, and
the very new few receivers purchased for SDRE survelliance purposes 
became R&S or Deutsche Aerospace units, and the SRT units were
refurbished to prolong their service life. 

The MFA then bought the Rockwell/Collins Mediaware or Spectrum-2000 
system which turned out to be
an expensive but mediocre performer which in the end lead to the 
complete abolishment of the MFA HF operations.

73/
Karl-Arne
SM0AOM

----Ursprungligt meddelande----
Från: michaelob666 at ntlworld.com
Datum: 2013-01-05 17:22
Till: "PREMIUM-RX"<premium-rx at mailman.qth.net>
Ärende: Re: [Premium-Rx] WJ-8711A or WJ-8712P

Dear Paul

Many thanks for your helpful comments.  I am sorely tempted!!  
However, 
another line of thought is saying to me that direct digital 
conversion 
is 
the way ahead and to wait for a while and skip the 8711 generation.  
There 
is a brilliant new Swiss-made HF transceiver where the limiting 
factor 
to 
reception is harmonic interference from the PSU, and even that is 
low. 
Can't recall the name but they have a tie up with Rohde & Schwarz, 
who 
really do understand such matters.

If only someone would make a receiver or transceiver with direct 
digital 
conversion but with the panel of an 8711 at a price far removed from 
some of 
the new R&S stuff.  A radio dependant on a laptop is just not for 
me.  
I 
want a proper radio in a chunky case with a nice weighted tuning 
knob 
and 
other knobs of the Berco variety (as on the RA1772), a decent Sifam 
or 
Simpson meter and quality push buttons and displays.  Beside that I 
don't 
have a modern lap top and in any event their screens are far too 
small 
to 
read easily.

I find you either love or hate a receiver and I suspect you rather 
agree 
:-).  My keeps forever (so far) are the RA17L plus its many add ons 
in 
a 
tall robust rack, the RA1772 and my RA3701.  I like chunky radio 
with 
interesting mechanics, though I am beginning to need help in moving 
them now 
:-( .

My dislikes are most Eddystones (though the 1650 is quite fun), the 
Drake 
R7A and the STC STR8212.  The last is old now but was built the hard 
way and 
has superb DSP selectivity figures that exceed WJ's, but the fan 
noise 
and 
poxy tuning would drive a monk to murder.  It was clearly not 
designed 
to be 
used by a human hand for long.

73s
Michael
G8MOB

----- Original Message ----- 
From: <paul at 8zo.com>
To: "Michael O'Beirne" <michaelob666 at ntlworld.com>
Cc: "PREMIUM-RX" <premium-rx at mailman.qth.net>
Sent: Saturday, January 05, 2013 3:31 PM
Subject: Re: [Premium-Rx] WJ-8711A or WJ-8712P

The WJ-8712P receiver is in a package with a front panel that is 
approx. 
8-1/2 wide by 3-1/2 high.  The depth is a desk-challenging 20 
inches, 
but 
the small front panel footprint and light weight make that an 
acceptable 
trade-off.  The WJ-8712P will do everything a WJ-8711/HF-1000 will 
do 
spare 
two notable things.  The front panel volume control adjusts the 
headphones 
only and not the speaker output, through a simple three wire jumper 
job 
reverses that.  The second thing is that the analog meter has been 
replaced 
by an LED bar-graph.  After a short period of adjustment, I actually 
*like* 
the bar graph as it is located directly below the least significant 
digits 
of the frequency display allowing easy tuning for maximum signal 
strength 
vs. frequency at a glance.  Operation is so similar to the 
8711A/1000 
receivers that there is virtually no learning curve.

I have all three receivers side-by-side, and the superior 
performance 
of the 
8712P is very evident.  The (expensive) push-buttons on the front 
panel are 
all back-lighted a cool green matching the displays.  This is a 
*beautiful* 
receiver!  The shielding does its job as there is no detectable 
spare/strange noises.  Internally, the 8712P has the same boards as 
the 
latest 8711A receivers.  Only the front panel and package are 
different. 
The standard 8711A preselector option may be used, though mine has 
an 
enhanced two-board preselector in it, presumably intended as a 
"special" 
unit for a government agency.  It was originally purchased directly 
from 
DRS/WJ by a person who made the short drive from his office to the 
company 
to pick it up in person.  Fortunately, I was able to make a deal to 
buy it 
from the original owner!  Yes, it was expensive, but it is at times 
my 
favorite receiver so well worth it!

The shortcomings of the 8711/8711A/1000/1000A have been well noted.  
As 
others point out, a late 8711A/1000A is certainly better than an 
early 
8711/1000.  There are some steps detailed here by Steve and others 
to 
mitigate the shortcomings somewhat.  Even so, I just cannot help 
myself, and 
really like operating all of these receivers.  They are really a lot 
of fun 
in a lightweight package!  BTW: there is an interesting story of 
these 
"reduced cost" receivers (including the Ten-Tec RX-340) that was 
told 
here 
some time back by our friend Dr. Jim Garland, W8ZR.

In short, the WJ-8712P is one of the few radios on my permanent 
"never 
sell" 
list.  IMO, it is *that* good!

Vy 73 de Paul  W8ZO

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