As in the WJ-8711A and HF-1000(A), we see a switching power supply in the RX-340 as well.
I know this does not have
anything to do directly with the RX-340. Anyway,I found the
picture below irking on the internet. A "top" inside
picture of the old 1986 Ten-Tec RX-325 . This of course was a
real D-O-G back then. Not very many were manufactured and for
good reason. The reliability and performance factor was at the
bottom end of the scale. Even back then we see the "rats
nest" of wires all over the place. It makes the RX-340's
wiring look neat. RX-340 internal pictures can be found at the
very bottom of this page (might take a bit to load these, try
hitting refresh if you only get part of these). Ten-Tec has come
along way since this receiver bomb.
Dave N9EWO
RX-340 comments from N9EWO and others
Display quirk noticed in 2005 sample /
Sync detector continues to be a joke
With a "brand new" 2005 sample I checked out
in the summer of 2005, a couple of notes. Note: I do not
personally own a RX-340.
The main (larger) display had a nasty to my eyes that was not
acceptable. Segments were not evenly lit. The main display is
made for Ten-Tec in Korea by Samsung. Being almost a $ 4300.00
receiver , I feel that Ten Tec should be rejecting these when
they look this bad (picture below that I took of the actual
display). There is simply no excuse for this.
One other side note is that the
"Sync Detector" continues to be almost worthless. It
simply cannot hold lock, it keeps popping in and out even on the
strongest signals with no interference around. It makes for a
real aural treat when it's working, but more times than not it
does not cut it for my standards. Try again
Ten-Tec !
Even with the WJ8711A's sync only being double sideband, it sure
holds lock much better over the RX-340 any day.
Dave N9EWO
Takashi Kuroda in Japan passes
along this firmware information on the RX-340.
I have an updated information on the RX340. The new
software version is 1.10A. 9.0khz tuning step and notch
filter bandwidth is now expanded up to 6khz.
I do not own the RX340 but I have learned from a friend of mine
who acquired a new version of the RX340 from the U.S.
Takashi Kuroda
Firmware
Display on the Ten-Tec RX-340
(Picture and
report via Takashi
Kuroda)
From : Albert P. Belle Isle
The ability to use the (rather obscurely named and unlabled)
"channel control" toggle under the speaker gain control
provides a quantized version of PBT in SAM mode. By changing it
from its default value of "BOTH" to either
"USB" or "LSB," you are switching from true
SAM to ECSS mode on whichever sideband has the least
adjacent-channel QRM. I must admit that it does work rather well,
but I'll still appreciate the more continuous variability of true
PBT in SAM when it's added.
After experimenting with my new RX340 (v1.01C logic firmware),
and calling TenTec for the answers to questions not apparent from
the extremely abreviated "manual," I thought you might
be interested in clarifying some points:
(1) There is (and apparently has always been) a dimmer function
in the RX340 (if not in its "manual"). You just have to
hold-in the [SETUP] button, and turn the Memory Scan Edit Knob to
the desired level ( 1% to 100%).
(2) Assurances of a 100 channel memory limitation
notwithstanding, I'm currently using over 140 of the 200 channels
available via the Memory Scan [SCROLL] button (or by entering the
desired number by keypad and hitting [SCROLL]).
(3) Contrary to the specifications, PBT can, indeed, be used in
AM mode. It can not, unfortunately be used in SAM mode. Whether
used in AM, USB or LSB, it really separates the weakest little
"sheep" from all the surrounding "goats."
(4) Most importantly, the bandwidth stored in a channel memory
when in SAM mode IS whatever you have currently set, and DOES
restore correctly when called up by [RECALL]. The bug is in the
fact that the display logic for the Memory Scan window apparently
is programmed to always show BW=6000, which was probably the
default value in the initial version of the firmware. (Allowable
SAM BW values are from 4KHz to 16KHz.)
My overall initial impression of the RX340 is very favorable.
It has a noise floor even lower than the little RX320 (which is
amazingly good for a low-priced consumer receiver), and
selectivity as good as the Collins mechanical filters and PBT of
my old modified Icom R71A.
With only 16-bit DSP arithmetic, the ultimate rejection must be
coming from the fact that the total signal chain provides
sufficient dynamic range and preselection prior to the last IF to
center the DSP's 96dB of max range right where it has to be.
The RX340's SAM mode must be heard to be believed; it's
outstanding.
When the next version firmware is delivered with the promised PBT
in SAM mode, this is going to be an amazing receiver for its
price. Now, if we can just get a _real_ manual (and kill the
little RECALLED SAM BW display bug)
Comments sent along to us by W.
Charles Alexander KC8IKG on the RX-340. He threw these questions
to Ten-Tec, and the answer's below. But I'm still not keen on the
mess of wires all over the place. More so between the front panel
and main body of the set (I do not agree with Ten Tec's answer).
"1) Why so many loose wires instead of ribbon
cables?"
"For isolation from signal coupling. Using ribbon cable
increases the possibility that signals sent through them will be
subject to unwanted coupling and degradation of RX
perfromance."
"2) What DSP ? The same Analog Devices "Sharc"
ASDP-21061 used in the NRD 545 and the Icom 756PRO?"
"The DSP processor is the Analog Devices 2181."
DaveZ Note: This is a 16 bit DSP . The current version of
the WJ 8711A uses a Motorola "24 bit" DSP56002 series.
"3) Any possability of allowing more bandwith choices in
Sync detection?"
"Yes - we've already done this. Sync AM can be used from
4 to 16 kHz bandwidth."
(Very Good news here of course-DaveZ)
"4) How many memory channels are there?"
"100." (now turns out this is 200-DaveZ)
** Initial Report on Ten Tec 340 ** by Donald
Nelson