Anytone Reciever Delay with Anytone DMR

[R22Beta]

So I've noticed a slight delay on my Anytone radios when I do simplex. It is normally not very bad so I just wait a second to talk. However I recently realized my 578 radio can be set up as a repeater. The repeater works great when I use Analog modes, but when I try to use DMR mode the delay seems that its in multiple radios. It cuts off the first second or 2 of the transmission and is quite distracting.

Does anybody know how to get rid of the delay on Anytone radios when using DMR mode?

 

[alcahuete]

There is always going to be a delay when using digital, as there is processing that has to take place. Processes analog (your voice) to digital, then digital to analog (through the speaker) on the other end. There is no way to get rid of that. That's just the inherent delay when using any digital mode.

It sounds like you're talking about something different though. It shouldn't be cutting off the start of your transmissions. If you don't use a talk permit tone, use one. Even though that is technically meant for letting you know that a connection has been established to a normal repeater, even if you use it in simplex or with the Anytone "repeater" that should prevent you from talking until that tone is clear.

 

[R22Beta]

Thanks alcahuete! That's too bad about the delay, but mine is really bad. I uploaded a video if it helps. Does this seem normal?

 

[alcahuete]

You're welcome! Yeah......I mean....some of those in the video seem normal, some (especially the one at the end) seem ridiculously long to me.

I don't have your setup, unfortunately. I don't have a 578 or two 878s, but I did some testing through one of my repeaters with a XPR 7550e and 878, as well as simplex.

I noticed something very interesting that I haven't really noticed before. When I transmit with the 7550, the 878 lights up darn near immediately. There is of course the few millisecond delay in the voice, associated with digital, but the actual receive light turns on immediately.

When I transmit with the 878, however, there is a somewhat significant delay, basically matching the short delay ones in your video. The same exact thing happens on simplex.

So it is almost like the Anytone is taking a while to transmit, and I'm not really sure why. The 578 might very well be adding to the delay as well, if it is taking its sweet time to transmit as well. Really interesting!

 

[chief21]

The delay in your setup is clearly noticeable, and I expect it is the result of adding additional delay(s) to the normal digital delay inherent in DMR. Unlike a purpose-built repeater, the '578 - while able to repeat a digital signal - probably doesn't have the necessary horsepower to process (decode) the received DMR signal and simultaneously re-process (encode) the DMR signal for repeating. Then figure the processing time necessary for the receiving HT to process the repeated signal from the '578. Lots of cumulative delay involved. In normal use, however, without the radios next to one another, users might not be as aware of the delays involved.

 

[WA0CBW]

Could be the TX delay is set a little longer for sending APRS packets through a repeater. This allows the repeater to come up to speed before sending the packet.
BB

 

[alcahuete]

Unlike a purpose-built repeater, the '578 - while able to repeat a digital signal - probably doesn't have the necessary horsepower to process (decode) the received DMR signal and simultaneously re-process (encode) the DMR signal for repeating.

He says it also happens in simplex, which is puzzling, since that takes the 578 out of the picture. As noted, there is a delay with mine too, though not nearly as large as the delay with his. On the Anytone, there is a delay from when you push the PTT to when the radio actually transmits. I don't know what is happening during that delay, but there is definitely a noticeable delay compared to my Motorolas.

 

[R22Beta]

That is correct, I do notice a slight delay with simplex. I was thinking that delay is compounding. If you watch the video above and see when I key up the PTT and then you see the TX light come on about a half second later and then there is a delay before the 578 indicates it is transmitting. However, the receiving radio seems to go into RX mode as soon as the 578 keys up.

I wanted to see if I could make it faster in simplex (but I failed). Nothing did in the codeplug seemed to make the radio transmit faster in digital mode (again analog is basically instant). There is a 0.6second delay (timed multiple times with a stop watch and averaged) between keying up and the radio indicating it is transmitting.

Among other things I tried:
-Updating the firmware to the latest (1.21 to 1.24)
-Removing the bulk of my programmed channels and contacts.
-Removed the startup picture (hoping to free up memory)
-Changed from half slot to double slot transmitting (thinking it might be trying to wait for the time slot to sync or somthing)
-Found anything in the options that sounded like it might add a delay and set it to the minimum number possible

Nothing I did reduced it to less than 0.6seconds before transmitting.

 

[R22Beta]

The delay in your setup is clearly noticeable, and I expect it is the result of adding additional delay(s) to the normal digital delay inherent in DMR. Unlike a purpose-built repeater, the '578 - while able to repeat a digital signal - probably doesn't have the necessary horsepower to process (decode) the received DMR signal and simultaneously re-process (encode) the DMR signal for repeating. Then figure the processing time necessary for the receiving HT to process the repeated signal from the '578. Lots of cumulative delay involved. In normal use, however, without the radios next to one another, users might not be as aware of the delays involved.

I think you are on to something regarding the HP of the 578. I just did another test and turned on AES in addition to the repeater mode. I actually seemed to have locked up the radio and had to power cycle it to get it back. It definitely seemed to struggle with doing everything.

 

[mitaux8030]

Another thing to remove will be any talk permit tone. The radio doesn't have the CPU horsepower to begin the preamble TX / repeater handshake while simultaneously issuing any audible talk permit tone. It has to do those things sequentially, which adds some delay.
While you don't specifically mention it, also set the Wake Head Period down to minimum recommended (probably 1 frame, which is 60ms)

 

[R22Beta]

Thanks, I turned that down. Hopefully that will save a few mS

Does anybody know if I have to have DMR in both of the VFOs for the repeater (or either)? If I put Analog in receiver VFO would the transmitter just rebroadcast the digital signal a not not have to be decoded and then recoded?

 

[alcahuete]

Thanks, I turned that down. Hopefully that will save a few mS

Does anybody know if I have to have DMR in both of the VFOs for the repeater (or either)? If I put Analog in receiver VFO would the transmitter just rebroadcast the digital signal a not not have to be decoded and then recoded?

If you are using analog, there is no encoding/decoding involved.