** Initial Report on Ten Tec 340 **
copyright 2000 by Donald Nelson
**This report is copyright 2000 by Donald Nelson. You are granted
usage only if reproduction includes appropriate credit.
Disclaimer: This report is an initial assessment after three days
of use on a dxpedition for purposes of logging both SW and MW
Pacific stations from the coast of Washington. It represents a
field test rather than a direct comparision of receiver
performance specifications. Some of the findings I will hope are
either easily corrected cockpit errors, or that firmware
improvements will be made quickly to correct these minor
deficiencies.
** Initial Assessment - Order and
Arrival.**
As a HF1000A junkie, I was disappointed by the departure of WJ
from the hobbyist receiver market. It is my personal experience
that the combination of the HF1000A with the Sherwood Engineering
SE-3 Delux will out-perform all other high end receivers I have
tried (Collins 2050, Harris 590A, Cubic 3030B) for detection of
faint DX (the remaining combination of R390A with SE-3 is yet to
be tried by myself) including using extremely low gain, low noise
antennas (Beverage, EWE, Pennant, Flag, K9AY). After overcoming
my trepidation about ordering the first serial numbers of an
expensive new receiver, I placed the order through Universal
Radio.
When the receiver did not arrive as promised in April, I called
and discussed the situation with TenTec’s VP of Engineering.
He explained that this was not a case of birthing pains of a new
product as the 340 is based upon the widely successful TT330
receiver supplied to key government agencies (NSA?). To build the
340, TenTec created a new front panel as well as adding some key
features used by the hobbyist. The delay cited was due to the
development of Synchronous AM and Passband Tuning.
**Arrival and Unpacking**
After the receiver did not arrive in June, I settled in for the
“long wait”. I was surprised when Universal Radio
called to tell me they would be shipping in mid July. After
discussing the shipping delivery time, I arranged an upgrade to 2
day AIR to allow the receiver to arrive in time for a DXpedition
to the coast of Washington with Guy Atkins and John Bryant.
Targets for the weekend included weak Indonesians (300 Watt) as
well as the usual Papua New Guinea targets, and a broad array of
medium wave stations throughout the Pacific.
Upon arrival on my doorstep, I opened the box. None of the fancy
foam and cardboard precision inserts found in WJ HF1000A boxes,
which is disappointing if one intends to reuse the shipping
materials to transport the receiver. The TT340 was swaddled in
bubble wrap and simply floating inside the single layer cardboard
box from TenTec.
What a beautiful front panel! I am in love with the simple layout
(not unlike WJ) and the visually appealing meter calibrated in
both S-units and dB. The lighter color of the front panel stands
out significantly from the WJ’s - as seen in the attached
picture of the listening setup while down at the beach this
weekend.
Size, at 3 RU (rack units) high and standard rack width of 19
inches - is identical in front panel area to the HF1000A. However,
the depth of the unit is only 2/3 of that of the HF1000A. Weight
is listed at a mere 12.5 pounds, significantly down from the 22
pounds of the WJ. This means I finally have a premium receiver
that can be adequately packed and carried onto an airline as
cabin luggage. Popping the covers reveals that unlike the WJ,
there isn’t a space inside the chasis suitable for carrying
ones lunch and thermos of coffee .
The manual was a disappointment - early copywriter version. Yet a
final copy is offered as an update when available to those that
respond with their warranty cards. The manual does serve to
adequately document most of the features. I found it vague in one
area --- the “AF channel switch” which was only
mentioned once under “4-6 Mode Buttons” and not so
identified elsewhere on panel layout or in the manual. This
turned out to reside under the Speaker audio gain knob as the LSB
- ISB - USB button and indicators. It allows one to select the
sideband with SAM (or ISB).
**Antenna Attachment and Initial
comparision**
I attached the TT340 to my standard multicoupler arrangement (Stridsberg
Engineering MCA-108 http://www.stridsberg.com/prod01.htm) for A-B
comparisions against the HF1000A (w/SE-3) using the EWE antenna
at my home. Both receivers have a simple BNC connector which in
my opinion is far more reliable than the SO-259 connection seen
on some receivers.
After noting that the manufacturer promises upgrades through swap
of 3 IC’s (flash or eprom?), and that the panel region
contains 2 switches labeled OPT-1 and OPT-2 (as yet not
implemented), there is significant hope for future upgrades. This
is especially important as Robert Sherwood reports finding a bug
in the SSB DSP, and I have located a bug in the memory firmware.
Initial powerup - wow! The display is an amazing blue color, more
pleasing to the eyes than the urine-green of the WJ under normal
fully lighted room operation. Yet, with the room lights dimmed (typical
of DXpedition late night operation), there is a definite
harshness to the display when compared to the WJ. This could be
corrected by TenTec by providing a dimming arrangement for the
panel brightness (none found nor mentioned in the manual -
hopefully an undocumented feature or perhaps planned?).
**Tuning Knob and Keypads**
The tuning knob feels great for a lightly-weighted knob - much
nicer than WJ’s simple plastic tuning knob (wonder if I can
buy spare knobs to retrofit my WJs?). Panel buttons and the
smaller knobs have a positive response that tells you when
you’ve activated them. I admit that I have a preference for
the dished numeric keypad that sits above the front face of the
WJ over the flat switches (not film switches) of the TT340.
Unfortunately for those of us that have become accustomed to the
numeric keypad of the WJ as well as other premium receivers, the
“0” and “.” keys are reversed from WJ. This
leads to a bit of relearning and/or many bad entries of
frequencies on the TT340 (for example, entering 2500 on the
keypad yields 25 decimal decimal. I can only wish for a little
future standardization in something so simple as a numeric keypad
on communications receivers!
The manual clearly calls out that keypad can be used for entering
auxiliary parameters and scan setup. It requires that you
remember to enter the number then a sign (+,-). Reversing the
order will merely change the frequency! I found this a bit
disorienting until one gets used to it.
**SAM**
I am deeply in love with the Synchronous AM mode of the TT340 ---
as a straight comparison between the two receivers (sans SE-3),
the SAM of the TT340 has a much better sound quality through the
phones (Senheiser and JRC ST-3). Neither receiver (currently)
provides SAM PBT (passband tuning), although this feature can be
had for both receivers through the addition of a Sherwood
Engineering SE-3 Delux. A downside of the TT340 is that the
minimum IF filter width for SAM is 4000 Hz while the WJ allows
selectable SAM IF Bandwidth to a very small frequency. PBT, Notch
(single frequency manual) filter, etc is disabled in SAM mode on
the TT340 (PBT is promised at a later date). A plus for the TT340
in SAM is that it allows selection of Lower, Upper or both side-bands
while in SAM, and SAM lock is shown by periods (S.A.M. instead of
SAM when lock occurs). Sideband selection is poorly documented in
the early manual (as “AF channel switch”) with the
buttons located under the speaker volume on the front panel. On
the WJ, a similar switch near the Speak volume controls only the
speaker, not the headphones. An outstanding feature of the SAM
mode is that the display shows S.A.M. when locked, and SAM when
unlocked.
In ISB, the “AF Channel Switch” functions to select
Lower, Upper or both side-bands for both phones and speaker (WJ
allows only speaker). I found this usable a couple of times while
listening to weak Indos such as Ngada (2899 kHz) and Mangarrai (2960.02
kHz) where the sidebands were differentially absorbed during the
incredible solar storm of July 15-17.
In LSB/USB, I am overwhelmed by the 340’s ability to shift
the PBT to achieve audibility. This feature proved awesome in
recovery of reasonably strong 738 kHz (Tahiti) over the local USA
AM stations on 740kHz with the TT340 (only use of the SE-3 on the
WJ gave it the audio edge over the TT340 --- without this
accessory the WJ is far behind the TT340 in LSB recovery of this
signal). The 340 outperformed the WJ on the recovery of Fiji on
1467 Khz, but
surprisingly did not hear as well as the WJ the weak signal of R.
Western on 3305 kHz, nor the weak signal recovery of Ngada on
2899 kHz.
The PBT on USB operates as one expects --- + numbers are higher
frequency and - numbers on the display are lower frequency.
Unfortunately, the LSB is reversed from this, which leads to
confusion for newbies as well as the need to remember which mode
you are in while tuning. This is documented in the manual but
does lead to confusion on the receiver --- this could easily(?)
be reversed by TenTec in the firmware.
**Tuning Increments**
Both receivers allow the user to select a tuning rate. WJ allows
either selection via decimal places or through an infinitely
selectable randge (so you could decide to use 8.33 kHz as the
tuning rate for whatever reason). Unfortunately the 340 allows
only a limited set of 8 selections - 1, 10, 50, 100 Hz, 1,5,10,100kHz
and 1 MHz. REMARKABLY the TenTec must not consider itself as
capable of penetrating the foreign MW market as they have left
out the obvious 9kHz tuning rate needed for foreign AM station
spacing.(We use 10kHz here in North America). I am hoping that
future microcode can fix this oversight.AGCAll of the four
selections on WJ are programmable.
The TT340 has 3 fixed and one programmable – with the
possibility of programming the attack, hang and delay. I found
that the fast mode supplied by the 340 was adequate for the
listening conditions I experienced. The TT340 also has a DUMP
feature - which removes the AGC whenever it is pushed and held in.
I had no occasion to utilize this feature although there could be
a use with a weak signal buried within a very strong one.
**Memory functions**
Operated similarly to the WJ. Only difference is in storing
options. I really appreciate the option to automatically find the
next available slot (starting from 0). A downside was the number
of buttons required to overwrite an existing channel - I had to
push store - the channel number (2 digits) - and then store. Much
simpler to be on the channel in the WJ and simply push store (as
well as doing it the way described for the 340). Perhaps this
exists on the 340 but I have not yet found it.The only bug I have
located to date is in the memory storage --- I expect that it
will store all the parameters set on the receiver. While it
selects only a subset, it also selects the wrong value for the IF
width. If I put the minimum for SAM in the receiver (4000 Hz),
and store in memory, the memory location saves 6000 Hz. While
this may be acceptable in some cases, it would cause a problem
where signal spacing is only 5kHz.
My usage of the memories is through the use of the TUNE or SCROLL
functions - both of which were adequate to scan through the
Indonesian and Papua New Guinea frequencies during the Dxpedition
(I located 23 different RRI transmitter sites and 17 different
PNG transmitter sites using the 340. Similar results were found
using the WJ. The only difference was a weak R Western that was
not well resolved by the 340 in LSB, USB nor SAM modes)
**PC-based RS232 Remote Control**
I am a user of ERGO for controlling the HF1000As and 535D’s.
I find this software to be outstanding for propagation prediction
as well as the world map and use of the ILG (and self created)
232 port to control multiple receivers! If you are planning on
setting up a multi-receiver listening post, you can control all
the receivers without resorting to switching the 232 line or
having multiple PCs.
There is another significant difference between the WJ and the
340 in the front panel disable when in remote control. The WJ can
be toggled in and out of remote operation from the front panel.
The manual for the 340 indicates that the front panel remote
button cannot be used to take the receiver out of remote
operation if the remote was entered through the RS232 control
port! I use the remote disable on the front panel of the HF1000A
to be able to offset the tuning while using the SE-3. I also
wonder what happens to the 340 if the PC goes
“bluescreen” while the receiver is in
“remote”--- can the user override or must you reboot
the PC operating system to reassert control? Something to try
shortly!(of course, your version of Windows operating system
never goes blue screen nor suffers from memory leaks, right?)
**Noise Blanker and Squelch**
Since the listening location was relatively quiet, I never had
need to use the noise blanker (which of course did nothing for
the normal tropical band noise found at frequencies less than
5000 kHz). Since I was Dxing and not program listening, Squelch
was not used, although it was tried and found to work adequately
(not a feature I will ever use )
**Use with an auxiliary DSP unit**
I use the Timewave DSP-599ZX to clean up a lot of the noise and
heterodynes. This unit works very well using the headphones
output of the WJ (avoids the issues with audio out of the “D-plug”.
Using the 599ZX with the 340, I note that the audio phones output
level is not great enough to match the input requirements of the
599ZX (fails to illuminate the light). I will have to see if some
of the jumpers can be changed within the 599ZX --- as the user
programmable gains were not sufficient. The output of the 599ZX
was quite usable for both program listening and for driving
several brands of Minidisk recorder.
**Use with an Sherwood SE-3 unit.**
Robert Sherwood assures me that the SE-3 as setup for the WJ (there
is an internal gain adjustment) is quite adequate. I have found
that the SE-3 works exceptionally well with the 340, just as it
does with the WJ, to provide PBT using the SAM mode. The only
advantage that the WJ has is that the SAM mode IF filtering can
be reduced to the more usable 2.4 to 3.2 kHz that eliminates near-frequency
interference.
Both receivers come with an BNC output of the 455kHz IF required
to use the SE-3. In addition, the 340 offers an additional 3 BNC
455kHz with various combinations of AGC, etc. One of these is
designed for the addition of a signal monitor (I’ll have to
try my WJ signal monitor to see how this operates).
**OVERALL ASSESSMENT**
I am greatly impressed with this receiver - it is a significant
advancement in the availability of “premium receivers”
to the general hobbyist market. TenTec has had a good track
record of upgrading the firmware for its Ham Radio (the Pegasus
and Mark Fine (Fineware) to helped debug their remote control
programs.)
**It’s a keeper!**
I expect that there will be significant interest amongst the
aging population of enthusiasts that now have sufficient
disposable income for the 4K pricepoint.
**I would like to thank TenTec for taking on this project in
light of the recent departure of WJ from the market segment of
high-end hobbyist commercial grade receivers.**
(Again, WJ still sells the WJ-8711A..DaveZ)
**This report is copyright 2000 by Donald Nelson. You are granted
usage only if reproduction includes appropriate credit.