Kenwood TS-850 mics and other stuff
Kenwood recommended either the Kenwood MC-60A or the MC-80 desk microphones for many of their solid state rigs, including the TS-450/690, TS-850 and TS-950 series. (If you have the owner's manual, check in the back and it'll list all the compatible accessories.)
It's still possible to buy the MC-60A brand new from some distributors:
Kenwood MC-60A Desk Microphone, Kenwood MC60 mic
As Captain Kilowatt noted, there's an impedance selection switch on this mic to select between 50Kohms and 500 ohms. For the TS-850, you'll want 500 ohms.
I happen to also have a Kenwood TS-850 and an MC-60A mic, and the combination works fine.
You're not the only one who's had trouble trying to get an Icom mic work to work with a non-Icom rig. I bought an Icom SM-10 a long time ago and tried to get it to work with my Kenwood TS-430, and had nothing but trouble. (I eventually got to the point where I the mic had power and the PTT and lock buttons worked, but the audio was mediocre at best. I also had lots of problems with RF feedback.)
The Kenwood TS-850 is a great radio, but the choice of a mic for it depends a little on what you're aiming for. Do you want to operate SSB or AM? Do you want it to be loud like a CB, or do you want high fidelity?
If you want CB-style loud, the tried and true D-104 lollipop mic will work on Kenwood rigs just fine. You'll want one that has a pre-amp circuit in the base though -- without the pre-amp, the D-104 impedance is way to high for a typical solid state rig. I have a D-104 with a TUG9 stand that I wired up with an 8-pic plug for Kenwood rigs, and it works with both my TS-430 and TS-850.
If you plan to go this route though, there are a couple of caveats:
- The amplified D-104 mics use a 9 volt battery to power the pre-amp circuit. Some people notice that the radio already provides +8v DC on one of the mic pins, and think: "Hey! I can just connect the +8v line to one of the unused wires in the mic cable and power the mic that way; then I won't need to buy 9 volt batteries anymore!" I used to think that too. Don't do it with the 850. With my TUG9 stand, the negative power supply line (black wire to the battery) and audio ground are connected together. In order to power the mic amp from the radio, the black and red wires will need to be connected to +8v and GND on the Kenwood mic plug. This will have the effect of connecting the GND pin to the audio shield pin (mic ground), creating a ground loop. When I did this, I ended up with a noticeable 60Hz hum in my audio. Putting the battery back the way it was fixed it. Long story short: don't try to get too fancy, just use the mic as-is.
- The pre-amp in most D-104 lollipop has way more gain than you will ever need with the TS-850, and you can end up over-modulating very easily. Be prepared to turn the gain control on the mic way down, and experiment a bit to find a good setting for both the mic's gain control and the mic gain control on the front panel of the 850.
- The VOX feature won't work. With the amplified stands, you need to key the mic in order to turn on the internal pre-amp. Until you do that you won't have any audio. (This is to help extend the battery life.) This means you can't just set the mic down with the VOX on and talk into it.
If you're interested in achieving the best fidelity that you can with the TS-850, then the choice usually comes down to one of the Heil mics, or a professional studio mic. Both will offer you good frequency response. Exactly which is better depends on your opinion. The Heil mics have the advantage of being designed for amateur radio use, and you can order it with whatever cable you need to connect it to your rig. Some people prefer studio mics so that they can hook them to audio processing gear (equalizers, compressors) to tailor their sound.
I use a Behringer B1 with my TS-850. It costs about $100, andit's a condenser microphone, which requires +48v phantom power to operate. I have a small Behringer Xenyx 502 mixer for that. I also use an equalizer and compressor. The latter two components both cost about $79 each, and the mixer was about $40. That's actually fairly cheap. (If I had it to do over again, I think I would go for the Behringer Ultracurve Pro DEQ2496. It's $300, but it combines pretty much all the things I have now into one unit, and the EQ is digital.)
If you really want to get the best possible AM hi-fi audio out of your TS-850 though, you'll probably need to make a few modifications to it. You can dramatically improve the low and high end frequency response with some fairly simple changes. I made a small write-up of what I did to my rig here:
http://people.freebsd.org/~wpaul/ts-850/850.html
(This page also has links to the owner's manual and service manual.)
If you've used the radio on AM at all, one thing you may have noticed is that factory-set ALC calibration is very fascist. You may have noticed a lot of "backwards swing," even with the carrier set at a conservative level. This behavior is common to a lot of solid state HF rigs. The link above tells you how to adjust the ALC to overcome this, however it should be noted that even with this change you'll get the best results only if you keep the carrier down to 25 watts or less. The TS-850 is designed for 100 watts of output, and the rule of thumb is that the amount of power produced on a modulation peak with AM is four times the carrier power. The owner's manual recommends a 40 watt AM carrier, but that would require 160 watts of power at modulation peaks, which is beyond the radio's design limits. The result is that with too high a carrier, you'll end up flattening out your positive modulation peaks, which will lead to distortion and splatter.
A few important notes about the TS-850:
- Check your serial number. If it's in the 20 to 30 million range, you will almost certainly need to replace the electrolytic capacitors on the carrier board. Kenwood ended up with a lot of defective caps from one of its suppliers and used them during the first couple years of production of the TS-850. The defective caps will leak, as in the electrolyte will leak out of them. This damages the capacitors, as well as possibly damaging traces on the carrier board. Luckily, replacing the caps and bridging the damaged traces with wire is fairly easy.
- Also on the carrier board are four direct digital synthesis (DDS) chips, with a part number of either YM6631 or YM66312. The 6631 parts were allegedly very fragile and prone to failure. The 66312 parts are functionally equivalent, but more robust. (if you have the 66312 chips in your radio, you can ignore the rest of this part.) These chips were custom made by Kenwood and replacements are no longer available. If you have the 6631 part, and the older caps, replace the caps ASAP! Some people have said that all 6631 parts are certain to eventually fail, but I think the failures are triggered by the bad capacitors. If your radio has the older chip and is still working, just be sure to replace the capacitors on the carrier board (assuming the previous owner didn't do it already).
- A couple weeks after I got my radio, the receiver failed. In particular, the receiver was dead quiet in all modes, except for FM. This is a sign that Q15 on the IF unit has died. This is a common problem for the TS-850. Q15 is a 3SK131 JFET. The original part from NEC is out of production, though you can still get it from some suppliers if you hunt. I used a BF998 as a replacement (available from DigiKey for about 50 cents each). Hopefully this'll never happen to your rig, but keep this in mind if it does.
- You might want to take the top cover off and check the battery (mounted to the digital unit right behind the front panel). If it's old and looks discolored, it may be leaking. If so, replace it ASAP.
I would recommend checking out the TS-850 repair page at:
850 Repair Page
It has info on these and many other issues about the TS-850.
-Bill
