Batboard

I just got another Maxtrac 300 UHF (449-470). I have about 10 of these in service as echolink/IRLP links around the state, and this is the first one that's given me this issue...

(It's not interfaced yet, so it shouldn't be a problem, as I take unsquelched audio from the interface connector, but...)
The squelch seems to take forever to open on receiving a signal. The receiver opens with a 225.7hz CTCSS, and takes more than 1/2second to open on TX from my HT. The other radios are nearly instant.
Programming is the same on all, except for frequency, and I can't figure out what's wrong here.

I haven't put the radio on the communications analyzer yet, but my frequency counter shows the radio is only about 600hz off frequency (I've seen worse), so the oscillator should be OK. I don't know what else to look for.

Any suggestions?
TNX
Brad
W0VHA

Squelch is turned up too high.. its one of the blue pots tht you manually turn down..

Check the VCO voltage to make sure it is well within the range for lockup. If its on the edge, lockup times can be very slow.

Could be a case of the board pins too - those pins between the logic and rf brd.

There is mod for Maxtrac and Radius mobile, squelch slow to open. I will have to look it up and post it.

I checked the squelch, and it's set properly. I'll take the radio in to work tonight and check the VCO (and clean the pins) and see what happens.

Checked out the radio this morning...
VCOs are both right where they should be, and I cleaned all connectors, including the interboard one.
Oscillator reference has been adjusted to within 20hz.
Squelch is set properly. Squelch opens at ~0.2uV, but takes its time doing it.

Maybe I just have a slow radio...

vhacmowilmob wrote: Maybe I just have a slow radio...

You need to do a mod to get faster un-mute. Are you into removing and replacing two small parts in your Maxtrac?

Will wrote:

vhacmowilmob wrote: Maybe I just have a slow radio...

You need to do a mod to get faster un-mute. Are you into removing and replacing two small parts in your Maxtrac?

Let me guess - a couple feedback caps on the squelch chip? Or on the mute gate? or both.

Will wrote:

vhacmowilmob wrote: Maybe I just have a slow radio...

You need to do a mod to get faster un-mute. Are you into removing and replacing two small parts in your Maxtrac?

If they're not SMT, I can do it... (my vision isn't good enough to play with SMT parts, even with the CCTV camera)

Will,
Can you post a link (or instructions) for this squelch mod? I have another (VHF) maxtrac with the same issue...
TNX
W0VHA