# Squelch tail crash at fault to Allstate on uhf quantar **URL:** \ **Category:** AllStarLink\ **Created:** [October 1, 2026, 11:33pm UTC](https://community.allstarlink.org/t/squelch-tail-crash-at-fault-to-allstate-on-uhf-quantar/25037 "2026-10-01T23:33:24Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![N2CUE](https://community.allstarlink.org/user_avatar/community.allstarlink.org/n2cue/32/5229_2.png) [@N2CUE](https://community.allstarlink.org/u/N2CUE)\ **Post date:** [October 1, 2026, 11:33pm UTC](https://community.allstarlink.org/t/squelch-tail-crash-at-fault-to-allstate-on-uhf-quantar/25037/1 "2026-10-01T23:33:24Z")
So I have an uhf Motorola quantar and I purchased my kit to connect to the raspberry pi through repeater builders website. Everything works well OFFLINE. The moment I connect and power on the pi with allstar, the repeater suddenly develops a squelch crash. Repeaters an unknown signal lets the repeater, you hear a squelch crash and it cycles again. The repeater will do this for up to a full minute and then give up. What causes this? I can see turn off the pi and immediately the repeater qilll act as normal. No squelch crash no nothing. Just a normal repeater. ---
**Author:** ![N8EI](https://community.allstarlink.org/user_avatar/community.allstarlink.org/n8ei/32/4254_2.png) [@N8EI](https://community.allstarlink.org/u/N8EI)\ **Post date:** [October 1, 2026, 11:53pm UTC](https://community.allstarlink.org/t/squelch-tail-crash-at-fault-to-allstate-on-uhf-quantar/25037/2 "2026-10-01T23:53:47Z")
What do you mean by "suddenly develops a squelch crash"? Normal traffic has a squelch crash at the end? Or the repeater is being continuously keyed up and transmitting noise? ---
**Author:** ![N2CUE](https://community.allstarlink.org/user_avatar/community.allstarlink.org/n2cue/32/5229_2.png) [@N2CUE](https://community.allstarlink.org/u/N2CUE)\ **Post date:** [October 2, 2026, 1:21am UTC](https://community.allstarlink.org/t/squelch-tail-crash-at-fault-to-allstate-on-uhf-quantar/25037/3 "2026-10-02T01:21:34Z")
Repeater will key and have a cycle of what seems to be squelch opening the receiver causing it to key, make a noise of what is effectively a squelch crash and then do it again. Unplug or turn off the pi and issue goes away ---
**Author:** ![N8EI](https://community.allstarlink.org/user_avatar/community.allstarlink.org/n8ei/32/4254_2.png) [@N8EI](https://community.allstarlink.org/u/N8EI)\ **Post date:** [October 2, 2026, 1:32am UTC](https://community.allstarlink.org/t/squelch-tail-crash-at-fault-to-allstate-on-uhf-quantar/25037/4 "2026-10-02T01:32:06Z")
If you look at `simpleusb-tune-menu`, are COR and/or CTCSS being triggered in when this is happening? You could have the signal line backwards. I'm not sure which way a Quantar signals. Something also tickles my mind that some people have had to build a buffer circuit for it? Search through the forums here for Quantar. There's a lot of Quantar users here so someone will likely chime in too. ---
**Author:** ![W2DB](https://community.allstarlink.org/letter_avatar_proxy/v4/letter/w/57b2e6/32.png) [@W2DB](https://community.allstarlink.org/u/W2DB)\ **Post date:** [October 2, 2026, 1:49pm UTC](https://community.allstarlink.org/t/squelch-tail-crash-at-fault-to-allstate-on-uhf-quantar/25037/5 "2026-10-02T13:49:30Z")
Jason- No need to make a buffer. see attached. I go from MRTI connector (DB25) to the RA4x. Works great, no wildcard tables needed. Uses the squelch detect and PL decode internal to the Quantar. No muss, no fuss. In the usbradio.conf: carrierfrom = usbinvert ctcssfrom = no [quantar-mrti - RA45-Schematic.pdf](https://community.allstarlink.org/uploads/short-url/mOIFzRVezmDxoqgMOdsEPNpUp67.pdf) (21.4 KB) GeorgeC W2DB ---
**Author:** ![WD6AWP](https://community.allstarlink.org/user_avatar/community.allstarlink.org/wd6awp/32/5_2.png) [@WD6AWP](https://community.allstarlink.org/u/WD6AWP)\ **Post date:** [October 2, 2026, 3:36pm UTC](https://community.allstarlink.org/t/squelch-tail-crash-at-fault-to-allstate-on-uhf-quantar/25037/6 "2026-10-02T15:36:09Z")
Is Allstar rpt.conf `duplex = 3` used with the MRTI setup? ---
**Author:** ![N2CUE](https://community.allstarlink.org/user_avatar/community.allstarlink.org/n2cue/32/5229_2.png) [@N2CUE](https://community.allstarlink.org/u/N2CUE)\ **Post date:** [October 4, 2026, 5:01pm UTC](https://community.allstarlink.org/t/squelch-tail-crash-at-fault-to-allstate-on-uhf-quantar/25037/7 "2026-10-04T17:01:02Z")
So after this discussion do we have an idea of what is what ---
**Author:** ![NQ4T](https://community.allstarlink.org/user_avatar/community.allstarlink.org/nq4t/32/4989_2.png) [@NQ4T](https://community.allstarlink.org/u/NQ4T)\ **Post date:** [October 5, 2026, 1:44pm UTC](https://community.allstarlink.org/t/squelch-tail-crash-at-fault-to-allstate-on-uhf-quantar/25037/8 "2026-10-05T13:44:56Z")
If increasing the COS delay (or whatever...there's a setting to ignore COS after PTT) doesn't work...then I would say you need to try adding some buffering or filtering to your interface. You...probably do need a buffer to prevent logic signals from going crazy. Your schematic just shows straight connections. ---
**Author:** ![N8EI](https://community.allstarlink.org/user_avatar/community.allstarlink.org/n8ei/32/4254_2.png) [@N8EI](https://community.allstarlink.org/u/N8EI)\ **Post date:** [October 5, 2026, 6:56pm UTC](https://community.allstarlink.org/t/squelch-tail-crash-at-fault-to-allstate-on-uhf-quantar/25037/9 "2026-10-05T18:56:16Z")
> [@N2CUE](#): > > So after this discussion do we have an idea of what is what No one can help if you don't answer our questions or provide any troubleshooting info.... ---
**Author:** ![NQ4T](https://community.allstarlink.org/user_avatar/community.allstarlink.org/nq4t/32/4989_2.png) [@NQ4T](https://community.allstarlink.org/u/NQ4T)\ **Post date:** [October 6, 2026, 12:58pm UTC](https://community.allstarlink.org/t/squelch-tail-crash-at-fault-to-allstate-on-uhf-quantar/25037/10 "2026-10-06T12:58:00Z")
The last time I saw this problem it turned in to the person really annoyed at how every other radio except the motorola's work. Sorry your $900 radio has a squelch tail since we all don't have $900 radios to match. ---
**Author:** ![WD6AWP](https://community.allstarlink.org/user_avatar/community.allstarlink.org/wd6awp/32/5_2.png) [@WD6AWP](https://community.allstarlink.org/u/WD6AWP)\ **Post date:** [October 6, 2026, 4:26pm UTC](https://community.allstarlink.org/t/squelch-tail-crash-at-fault-to-allstate-on-uhf-quantar/25037/11 "2026-10-06T16:26:21Z")
Yes, more information is needed. I think you said earlier adding AllStar to the Quantar caused the squelch tail crash. Let’s do some trouble shooting to see why that is. Normally, Quantars have next to no squelch tail (crash) on a strong signal even on radios with no reverse burst and a very acceptable squelch tail on very weak signals. Some cheap Chinese radios are the exception. Radios with reverse burst will have no squelch tail at all. This is one of the reasons repeater owners and users like Quantars. AllStar won’t change any of that. To test you need a receiver to duplex and listen to your repeat signal/audio. The receiver is needed because your transmitter may transfer to receive slower than the squelch tail. Be sure to not desense the receiver by not getting too close with the transmit radio and use low power. You may hear two squelch tails. One when you unkey and then one when the Quantar unkeys. Do you hear good audio and acceptable squelch tail(s). If not let us know. If we’re good so far we’ll need to make a change to either the Quantar or to AllStar. That’s because AllStar is default set to full duplex (as is the Quantar) which creates two repeat paths and a delay and echo. The repeat delay comes from AllStar processing and buffering. Which you change has a trade off. The easiest quick fix change is to set `duplex = 3` in AllStar’s rpt.conf file. The other fix is to set the Quantar up as a base station. This allows AllStar to mute DTMF but the Quantar will not repeat if AllStar or its computer fail. It also adds a delay where users may hear the last syllable of their own transmission when they unkey. Let us know how it goes. ---
**Author:** ![N2CUE](https://community.allstarlink.org/user_avatar/community.allstarlink.org/n2cue/32/5229_2.png) [@N2CUE](https://community.allstarlink.org/u/N2CUE)\ **Post date:** [October 6, 2026, 11:24pm UTC](https://community.allstarlink.org/t/squelch-tail-crash-at-fault-to-allstate-on-uhf-quantar/25037/12 "2026-10-06T23:24:58Z")
Now that’s an explanation I can deal with. Main thing I want is the repeater to pass the audio through. And as for a receiver per the other in needed comment I use either a Harris xg100p or my base or some other Motorola ht portable radio. I have my rquantar set to duplex=2 mainly because I want the in air traffic. I eliminated the hang timer timer to about half a second to reduce the squelch crash cycle and it did help Maybe setting the machine to base operation may be another option to eliminate this issue. ---
**Author:** ![WD6AWP](https://community.allstarlink.org/user_avatar/community.allstarlink.org/wd6awp/32/5_2.png) [@WD6AWP](https://community.allstarlink.org/u/WD6AWP)\ **Post date:** [October 7, 2026, 1:55pm UTC](https://community.allstarlink.org/t/squelch-tail-crash-at-fault-to-allstate-on-uhf-quantar/25037/13 "2026-10-07T13:55:34Z")
> [@N2CUE](#): > > Main thing I want is the repeater to pass the audio through. Then `duplex = 3` is exactly what you want. It's the same as `duplex = 2` but with no repeat audio. From the rpt.conf comments... ```auto duplex = 2 ; 0 = Half duplex with no telemetry tones or hang time. ; Special Case: Full duplex if linktolink is set to yes. ; This mode is preferred when interfacing with an external multiport repeater controller. ; Comment out idrecording and idtalkover to suppress IDs also ; 1 = Half duplex with telemetry tones and hang time. Do not repeat audio. ; This mode is preferred when interfacing a simplex node. ; 2 = Full Duplex with telemetry tones and hang time. ; This mode is preferred when interfacing a repeater. ; 3 = Full Duplex with telemetry tones and hang time, but no repeated audio. ; 4 = Full Duplex with telemetry tones and hang time. Repeated audio only when the autopatch is down. ``` ---
**Author:** ![W2DB](https://community.allstarlink.org/letter_avatar_proxy/v4/letter/w/57b2e6/32.png) [@W2DB](https://community.allstarlink.org/u/W2DB)\ **Post date:** [October 21, 2026, 5:57am UTC](https://community.allstarlink.org/t/squelch-tail-crash-at-fault-to-allstate-on-uhf-quantar/25037/14 "2026-10-21T05:57:17Z")
Just saw this. It can be duplex= 2 or 3. Depends on how Quantar is setup in "RF Config" tab. If set as "base" then duplex=2, when set as "repeater" duplex=3. Also be sure to enable phone patch in two places under channel info and hardware config. Sorry it took so long to respond. GeorgeC W2DB