maxtrac 900 squelch wont open

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The Kreick
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maxtrac 900 squelch wont open

Post by The Kreick »

I have a d27 900 maxtrac that i did the ham conversion on & everything looks a-ok, but the squelch wont open, nor will the busy light light. I have set the RX for carrier squelch, still wont open. I have keyed my GTX portable right next to it, & i can hear it on the maxtrac across the room, but not on this one, *but* if i hold the monitor down the squelch opens & i hear my HT ful quieting. Anyone see this before? Could it be the filters?

tnx

The Kreick
CTAMontrose
was grem467
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Post by CTAMontrose »

using the wrong conventional firmware will cause this as well, remember the firmware for the VHF/UHF/800 conventionals isnt the same as whats needed for the 900Mhz ones..

http://batboard.batlabs.com/viewtopic.p ... highlight=

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The Kreick
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Post by The Kreick »

I swapped out the firmware, and no change. anyone know of any other abnormalities to cause the SQ not to open at all, but receive a full quieting signal with the MON open? BTW set the RX to carrier SQ as well, still nothing....

tnx,


the kreick
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kcbooboo
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Post by kcbooboo »

Perhaps you selected an incorrect option when you reinitialized the board. There are several items in the lists that will make the radio do strange things. I converted an 800 MHz radio and when I finished, the unit was consistently several MHz off frequency. I blanked it and chose other options and eventually came up with a combination that worked properly.

Bob M.
The Kreick
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Post by The Kreick »

Bob- good idea, i will reblank & try again, once i get my laptop back up - my old slow toughbook died....waiting for the replacement to arrive....


kreick
Seth
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Post by Seth »

The Kreick wrote:Bob- good idea, i will reblank & try again, once i get my laptop back up - my old slow toughbook died....waiting for the replacement to arrive....


kreick
yea.. my 100Mhz Thinkpad finaly took the big sleep too ... trying to get a 266's HD to take a Win98 install .. after it had Win2Kpro .... not going well .... SIGH
W2PUT
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Post by W2PUT »

Make sure that the VCO isn't to close to the edge of operation.

I have run into the same problem and after spending many hours scratching my head and reproging with no success I noticed the VCO was near the edge. After a minor VCO adjustment it worked fine.

I don't know why that happens, but it will and the situation is repeatable, not just a onetime thing. One of the quirks I guess.
The Kreick
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Post by The Kreick »

That did it! I didnt think to look at the VCO, as we were TX/RX everywhere we needed, but it was low, and after a touch of conductive paint we are in business.

thanks for the advise!


kreick
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kcbooboo
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Post by kcbooboo »

Just going through some of the older posts and thought I'd also submit my $0.02 worth.

I had a couple of MaxTracs do that this year, but it didn't "click" into my head as to what was happening. Seems that if the VCO steering voltage is close enough to one limit or the other, the radio won't unsquelch when a signal is fed into it. You will hear the signal just fine if you manually put the radio into open squelch mode via the MON button, but it won't open the squelch itself. Even though the VCO is locking, something is unhappy about the frequency. Making a small adjustment to the VCO seems to clear this up. I think it happens more on 800 and 900 MHz radios, but it sure is frustrating, especially when you know that the channel has been programmed properly and you're feeding the right signal into the radio.

I have an 800 MHz MaxTrac that also seems to ignore the PTT request once in a while. I don't know if it's related to the VCO being modified, or if there's really a problem in the radio, but if I try to key it up while it's in the process of generating the reverse burst (PL), it won't always re-key. I'll have to yank the radio and try it on the bench to see if the VCO isn't locking (it was modified to receive 902-928) or if I have a logic board problem. In my application, I don't even need an RF board, but it is nice to be able to hear things.

Bob M.
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kg4lmt
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Post by kg4lmt »

Just out of curiosity...did you already jumper the two pins on the accessory connector that are normally used for an external speaker? If you are not using an external speaker they need to be shorted.
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