Batboard

Hello everyone: I understand fron a past posting from "Will", that the R100 has squelch tail elimination. Just got one going and it has a squelch tail. Tuned up per manual. The unit is PL. I checked all the jumpers per the service manual , all ok. Any ideas are welcome. Thanks Bob

just a thought..
make sure the radio using the repeater is transmitting the correct "reverse burst".. without it you will probably hear a little squelch when the transmitting unit unkeys.

If you are talking about repeater "hang time" which is the time period the repeater stays keyed after a user unkeys... I don't know what the capabilities of the R100 are in that respect.

Good Luck!

The R100 receiver in PL or DPL does crash when 'hearing' X brand radios that do not transmit ''reverse burst".....

The Mod for that is NOT covered in the R100 service manual.

My mod, first used in 1989, is used in many R100's around here..

On the main board in the door on the R100.

Remove JU16 and JU17
Install JU14

This gives you 'AND' squelch. The receiver has to have a valid PL/DPL AND a carrier un-squelch to pass audio and key the repeater.
The receiver also will squelch and drop the transmitter when either PL/DPL OR carrier is lost.

No more squelch crash with any radio going thru the repeater.

Will wrote:The R100 receiver in PL or DPL does crash when 'hearing' X brand radios that do not transmit ''reverse burst".....

The Mod for that is NOT covered in the R100 service manual.

My mod, first used in 1989, is used in many R100's around here..

On the main board in the door on the R100.

Remove JU16 and JU17
Install JU14

This gives you 'AND' squelch. The receiver has to have a valid PL/DPL AND a carrier un-squelch to pass audio and key the repeater.
The receiver also will squelch and drop the transmitter when either PL/DPL OR carrier is lost.

No more squelch crash with any radio going thru the repeater.

"Will" I did try your mod but there is still a short tail, but much better than before. The squelch adjust pot on the RX control board will shorten the tail a bit but not like our Micor and MSR2000 repeaters that use the "and" squelch option. Think the beep tone from the ID-8 that I will install may just cover it. Do you think the receiver ic could be in trouble. I did check the caps in that area. Thanks for your help

Thats because your MICOR has a hysteresis based squelch using an M7716 squelch IC that is legendary in the industry. Do some research on "Micor Squelch" and you'll see what I'm talking about.

The MSR 2000, though not as good as the MICOR also had pretty decent squelch action on it.

Unless you add an aftermarket Micor squelch board to it, that R100 will never have squelch action like your other repeaters.

d119 wrote:Unless you add an aftermarket Micor squelch board to it, that R100 will never have squelch action like your other repeaters.

OH.. There are a few other things that can be done with the R100 squelch circuit...

drbob - squelch tail elimination is purely a function of the PL circuit. ie: that brief moment of squelch noise heard in the repeat audio after a mobile or portable dekeys before the repeater squelch circuit mutes the receiver. The mobile/portable transmits PL/DPL to access the repeater which decodes it and enables the path. When they dekey, they are supposed to send a few hundred milliseconds of reverse burst / turn off code which the rptr decodes and immediately mutes the rcvr and starts the hang time counter. If the portable or mobile do not send reverse burst or turn off code, the squelch circuit fade hysteresis will to coast along for just a bit with the audio path happily passing squelch noise to the transmitter. You can speed up the squelch clamping by tightening the squelch, but now you are bumping up your minimum signal requirements to open the repeater. You should (a) verify your repeater properly decodes reverse burst, and (b) verify your mobiles and portables are sending it.

eta: Repeaters also send reverse burst which should mute a portable or mobile rcvr immediately as well. You should (c) verify your portables decode reverse burst properly too.

Use DPL, DPL uses a turn off code that's pretty much standard across the board on all brands of radios. The phase shift for PL on a Motorola radio is 180 deg, I believe Kenwood is 270, deg and I don't know what some of the others are. I do know Kenwood puposely made theirs non standard as compared to Motorola, GE, and RCA. All other manufacturers for a time didn't have the STE and you could hear it on a Motorola radio. Was a sales gimmick if I recall correctly.