[Kenwood] TS-950SDX

[Bud Hippisley, K2KIR]

>From: "Donald E. \"Buck\" Stiles" <n8csp@triton.net>
>I am soliciting constructive comments regarding the Kenwood TS-950SDX.  If you have an opinion on this radio, I would like to hear it, good, bad or indifferent.

I have a TS-950SDX  --  actually, I have two of them.  Here's why:

1.  I'm partial to Kenwood's ergonomics, starting with the old TS-180, and running through the TS-930, TS-940, and TS-850 to the TS-950SDX.
2.  Like the 930 and 940, it has really great QSK CW, without shortening of the first dot.
3.  The receiver synthesizer is very clean.  (Same generation as TS-850.)
4.  I wanted dual receive.  (Note -- the sub-receiver is meant to be used only on the same ham band, not cross-band.  Although you can get the sub-receiver to operate on a different band through a "secret" menu item, it has lousy sensitivity there because it's still using circuits tuned for the main band.)
5.  It has the Quick Memory function in a 5-tall push-down stack.
6.  You can independently select TX and RX frequency sources:  VFO A, VFO B, and MEMORY.  I run my CW traffic nets by putting the TX on a MEMory; then I can tune around the net frequency with the main tuning dial whether I'm transmitting or not.
7.  It has a separate RX antenna input for bringing in Beverages, etc.
8.  The built-in antenna tuner has memory, even tho the manual doesn't mention it.  So when you change bands, the tuner automatically sets itself up properly for the new band/frequency.  In contrast, the 940 tuner has no memory.  Whether using an amplifier or running barefoot into different SWRs on the different bands, this feature alone is a hidden "jewel".  
9.  The TX audio is typical excellent Kenwood communications audio.
10.  The CW waveform is excellent, and the rise and fall times are menu adjustable to prevent key clicks.
11.  It has nice peak-reading hold circuits for the metering LEDs.
12.  It has a built-in keyer and three built in CW messages.  By adding the voice synthesizer option, you can also have three built-in voice messages, or two built-in messages and a continuous off-the-air recording loop for convincing yourself of a callsign, etc.
13.  It uses a conventional hi-IF / low-IF selectable filter scheme to obtain excellent intermod performance.  Some people replace the stock Kenwood filters with International Radio filters to get steeper skirts.  I have not felt the need to.  
14.  It has some DSP functions, most of which I set once and then "forget".

What don't I like?

1.  It doesn't have a standard d'Arsonval meter.  (pardon my spelling.)
2.  RF coming in the RX Antenna input from, say, a Beverage wire, can cross-couple into the TX stages during transmit.  If you use a separate RX antenna, you should add some external circuitry to ground the RX Ant input during transmit periods.  (A number of other kinds of rigs have been reported to have the same problem, I should note.)
3.  It sometimes needs a pre-amp on 10 meters.
4.  The RX audio peaking filter on the 940 does a better job than the DSP filter on the 950SDX.
5.  Unlike the 940, the CW pitch cannot be set below 400 Hz.  I much prefer 300-350 Hz for separating stations with my ears.
6.  You have to use the outboard RM-1 remote control (or a homemade equivalent) to run the three CW/SSB message generators.  Unlike the TS-850, there is no way to record or start the messages from the front panel.
7.  The RX/TX transition when monitoring CW in QSK mode is not as "smooth" as on the 940 or 930.  (There's more evidence of gain pumping.)  This is a local monitoring issue -- there's nothing wrong with the transmitted signal -- and I've gotten used to it.
8.  The CW sidetone monitor level is only adjustable on the underside of the radio, and does not track with the main volume control.  (I modified mine to allow me to at least adjust it with the front panel MON control.)
9.  Compared to the 940, the RIT/XIT tuning is too slow for me (i.e., too many turns to go a kHz).  On the other hand, it's far better than that of the 850, which is not an optical encoder and hence has no "push to clear" button, and which only goes 1.2 or 2.4 kHz.  For contesting, the 850's RIT was a deal breaker for me and the reason I bought my first 950SDX instead of two separate 850s.
10.  The set-up method for putting one VFO on a DX station's frequency and using the sub-receiver and second VFO to find and transmit where the DX is listening is cumbersome at best.  I finally wrote myself a "crib sheet" on a 3 x 5 file card that I keep near the rig.  I now can do it from memory, but it took me a long time.
11.  In general, the operator manual could be better.

Fundamentally, the 850 and the 950SDX represent the "next" generation of receiver performance from Kenwood compared to the late model 940s.  I don't think subsequent Kenwoods, such as the 870 and 2000, are as good as the SDX.  By the way, my two SDXs are near the beginning and the end of the production period for those rigs; there's virtually no difference in their performance, unlike the many significant synthesizer changes that occurred during the 940's production cycle.  

There was a time, shortly after getting my first SDX that I thought I would never completely leave my 940 for the SDX.  But today, if I could keep only one radio on the market, new or used, it would be the TS-950SDX.  I have friends who believe the Icom 781 or the Ten-Tec Orion are better receivers, and I've used both of those.  But to me, because of the ergonomics, my SDX is more fun to use.

Bud, K2KIR