Batboard

I have a Micom 2TS installed in my car. The antenna is a 16' whip tied over the car. It is attached to the rear quarter panel via a ball and spring mount. I am currently using a MFJ 993BRT automatic antenna tuner. The RF and ground cables from the tuner to the antenna base are about 6 inches long. The tuner doesn't seem to work very well. It tunes the Micom from 40-10 meters, but sometimes it won't tune 12, 20, or 40. If I reset the tuner, then it may tune those bands. However, if I try to use ALE, the tuner gives up and quits tuning, causing me to have to reset it. Recently I installed 4 gauge insulated, stranded aluminum wire for both the RF and Ground outputs, and now I can tune fair on 40, and decent on 30, 20, 17, 15, and 10. I cannot tune on 12 whatsoever.

The Motorola tuner is likely well out of my price range, and I've been waiting for a few months now for the Motorola/Mobat 16' whip I've ordered. What other tuners have you all tried with Micom radios? The SGC 230 seems to be a popular model for people, but price is somewhat still an issue.

How exactly does the Tune function work on the Micom? I understand that the radio sends 12 VDC down the RF line to power the tuner. However, I had to install an object MFJ calls a Bias Tee to inject 12 VDC to power the MFJ tuner. The Tune option does nothing with the tuner as far as actual power supply, but it does send the low wattage signal to prep the tuner for the frequency to be used.

What else should I try? I'm ready for a new tuner, since this one just doesn't seem to cut it, and the SGC model seems to tune an 8 foot whip down to 3.3 MHz.

Thanks!

First off the Wima antenna is well worth the money. That is what I run. The next "affordable" option would be the SGC-230 and a heavy duty ball & spring mount with a fiberglass hamstick tuned for 30 or 40 meters or lower. This would give the SGC a tuning range of 1.6-30. The 16' Mobat whip is too heavy for vertical and still too heavy for NVIS without a PVC support. It does work great on the Wima but is still too short for the SCG-230 which needs a 23' or 10mhz antenna to tune the full band split.

The Micom sends a constant 12v down the coax, not sure if the SCG will like it. For my base I run the SCG-230 and a 60' wire - works great!! However I have a DC blocking Polyphaser lightning protector in line. Next I want to try a bias T at the SGC and power it that way. The tuning feature will tune the SGC how ever I don't like it for base use when trying to find traffic on different frequencies as it wants to auto tune each freq. change. I run ALE with the tuner setting off and it too works great!

Oh another thing, use at least 1/2" wide ground braid never a round wire for the grounds!!!! Ground both the coupler and the ground stud on the Micom to the car chassis. Make sure the high voltage lead from the coupler to the ball stud is less than 12". Short as possible and a 12g wire is fine for this. Run the high power 30amp fused wire directly to the battery + post, same for the 7.5amp fused receiver wire. Never to another power point in the car/truck. Run the neg. lead from the radio to the chassis ground short as possible. As per the MIcom instruction manual, install a ferrite around the power leads right next to the radio connector. Install a second ferrite around the control cable anywhere in line with the radio and control head.