Batboard

I horse traded a VHF Maratrac and am having problems with the control head and channel scan. I have one of the older clamshell (A3?, A5?) control heads with three knobs: Off-Vol, Mode and Zone.

Off-Vol does as expected, Mode is an 8 position knob that apparently changes frequencies, and I have no idea what Zone does -- it's just marked A/B and I was told it was Scan On/Off.

Unit was programmed and checked by local Moto shop. The radio WILL NOT scan in any position with any combination of frequency and "zone". This includes various configurations of mic off hook, stop scan and all the other programming options available. Additionally, the radio will only receive on Channels 1, 2 and 3 and will transmit on 1, 2, 3, 4 and 5 with good modulation and proper PL, etc. Channel 3 is heard on Channel 7 but you can't transmit back on Channel 3's simplex channel.

The tech was befuddled and me, having a background in GE equipment but not extensive Moto knowledge, decided to turn this one over to this board for some possible solutions.

I am thinking the channel selector on the control head may be damaged or shorted in some way. The shop didn't have any old working heads to try, and I'm not sure exactly what I have so I'm afraid to hit eBay and the Batboard for a new control head.

Has anyone else ever had this problem? What about scan with this control head? The radio itself works great on the channels that actually operate. The one thing about the control head that makes me suspicious is the radio doesn't "beep" when switching between Channels 7 and 8, and does nothing on the A/B zone thing.

Any ideas?

Could be a channel selector switch that has gone bad on some contacts. The knobs get clobbered and the switch(s) gets broken.

I can tell you the channel selector switch is a BCD switch. The other selector switch, a SPDT, can either be a ZONE or a SCAN selector, depends on how the radio was programmed.

I'm willing to change heads and give this a try.

Dos anyone have a WORKING head like I described that you'd like to sell. I'd be happy to buy new in the box, if available.

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As for the mode select switch, dissasemble the head and see if the mode switch is split apart, the two halfs of the plastic switch housing sometimes seperate and makes the switch jumpy and erratic on some modes. If it is seperated just use a good quality epoxy, or even a sparing amount of super glue and a couple strong rubber bands or a zip tie around it to clamp it while the glue dries. If you have a small spring loaded clamp that works nice too! I have had three A3 heads, all the same problem, the mode switch was falling apart inside.

As for the scanning and zone switch, I went through this with an A3 unit a while back. You have to go to the control head type screen and set it for scan, otherwise it will never scan. This makes the Zone switch a Scan On/Off switch, but also limits you to 8ch instead of 16. Without scan you would have Mode 1-8 on Zone A, and Mode 1-8 on Zone B, for a total of 16 ch's. I gave up the additional 8ch's to have scan on the most important ones that i needed to be listening to.

Now if you really want a nice Maratrac setup, find an A7 99ch head and the advanced control cable to run it. I did that to mine after about a month of being annoyed at only having 8ch's. The A7 head gives you user programmable scan from the head, talkaround (direct) for each repeater channel, and of course the biggest benefit is that availability of 99ch's.

Their is some A7 heads floating around yet, but they are getting harder to come by. There was a few on here, and i got mine from a Batboard member who's username is Bob so you might want to ask him just in case. He had a large amount of Maratrac stuff at one time, not sure if he got rid of it all or not. I just saw a A7 head and cable on eBay the other day, went for about $100, which is cheap for them. The A7 head can use any of the Spectra or Syntor X9000 style mics and speakers, so you can add a DTMF mic if you need it.

Thanks for the replies. I checked the switch and didn't find any visible separation. I tried pushing things together and got a couple of "beeps" from the radio, but no overall change in how the radio operates.

I realize I'll have to go back to Moto for reprogramming the ZONE switch -- which I DON'T think was done. (You'd think a Moto shop would know this ...)

Is a replacement mode switch available and practical to field install? Can you still purchase the A3 heads from Moto? I only need 7 channels maximum but do need 100 watts due to our rural area, so the 8 channel configuration works well for me. This is also somewhat of a custom installation in a small car, and I don't want to replace the A3 with an A7 or A9.

The A7 head isn't much larger in over size needed for install.

I would suggest you check all the connections on the back of the head, make sure they are clean and not corroded, perhaps pushing on the head and the beeps that it created was due to a bad connection somewhere.

If you had a RIB you could program that bugger yourself, and have what you need to make any changes down the road.

If you can't find anything wrong with the connections on the back of the head you might want to get a different A3 head and try that. They are not made anymore, there is some limited parts availablility yet for the Maratrac, but not much from Moto.

Go with the big head you won't regret it. I have two mounted in my Jeep Cherokee.

Go with the big head you won't regret it. I have two mounted in my Jeep Cherokee.