Search found 291 matches

by G4EML
Wed Nov 24, 2021 10:39 am
Forum: General discussions
Topic: Proper filtering for private call and RX/TX freq shift questions
Replies: 5
Views: 248

Re: Proper filtering for private call and RX/TX freq shift questions

In answer to the second part of your question, a DMR radio cannot be used with split frequency simplex. If the transmit and receive frequencies are not the same it is assumed that you are using a repeater. The mode of operation then changes from DMO (direct mode) to RMO (repeater mode). The Timeout ...
by G4EML
Mon Nov 22, 2021 10:30 am
Forum: Off topic
Topic: does anyone have a TYT MD-2017?
Replies: 3
Views: 274

Re: does anyone have a TYT MD-2017?

Here are some notes for the MD380.

https://www.miklor.com/MD380/380-Language.php

Colin.
by G4EML
Wed Sep 29, 2021 7:23 pm
Forum: New members post here first
Topic: Greetings from North Carolina
Replies: 4
Views: 512

Re: Greetings from North Carolina

When you install OpenGD77 you do not load 4.3.6 into the radio, but you need a copy of it on your computer. The OpenGD77 CPS needs access to the file so that it can use a small part of it to build the OpenGD77 firmware. It is done like this to avoid licensing issues. Open GD77 does not support text ...
by G4EML
Tue Sep 28, 2021 10:34 pm
Forum: General discussions
Topic: SSB... AM
Replies: 1
Views: 561

Re: SSB... AM

No, the transceiver chip in the radio cannot operate on AM.

Colin
by G4EML
Mon Sep 27, 2021 9:28 pm
Forum: General discussions
Topic: Squelch contain hysteresis?
Replies: 8
Views: 1112

Re: Squelch contain hysteresis?

The PMR446 channels are 12.5KHz spacing but they have a 6.25KHz offset. So if someone is using a radio that only does 12.5KHz steps they will be half a channel off frequency. With a wide filter that is not too much of a problem, but with a narrow filter you could see the problem you have observed. C...
by G4EML
Mon Sep 27, 2021 6:55 pm
Forum: General discussions
Topic: Squelch contain hysteresis?
Replies: 8
Views: 1112

Re: Squelch contain hysteresis?

Listening to the videos it sounds like the signal you are trying to receive is not in the center of the channel. It may have a half channel offset. So when set to narrow bandwidth it is outside your filter. Switching to wide filtering allows the signal through. Are you sure you have programmed the f...
by G4EML
Fri Sep 17, 2021 5:31 pm
Forum: Hotspot mode
Topic: OpenGD77 Hotspot Raspberry Pi 3B+
Replies: 9
Views: 1757

Re: OpenGD77 Hotspot Raspberry Pi 3B+

If you purchased a new GD77 then it will have had the manufacturers firmware loaded. That doesn’t appear as a Com Port.

The Com port will only appear once you have loaded the OpenGD77 firmware.

So what you observed is perfectly normal.

Colin.
by G4EML
Mon Aug 23, 2021 5:09 pm
Forum: General discussions
Topic: Linux and Python CPS transfer program
Replies: 12
Views: 1713

Re: Linux and Python CPS transfer program

Also make sure that the cable is fully plugged in. I know that sounds obvious but some radios need a very hard push to fully engage the connectors.
by G4EML
Fri Aug 13, 2021 3:27 pm
Forum: Development updates
Topic: [From July 11th] New Release R2021 07 11
Replies: 27
Views: 11711

Re: [From July 11th] New Release R2021 07 11

That radio is the same as the Retevis RT-73 and Kydera CDR-300UV. Discussed previously here https://opengd77.com/viewtopic.php?f=7&t=1284&hilit=Rt73#p11288 It uses the HRC-7000 combined baseband and processor chip. This is different hardware to the GD-77 and has even less documentation available, so...
by G4EML
Wed Aug 11, 2021 1:38 pm
Forum: Hotspot mode
Topic: GD77 + MMDVM Host problems
Replies: 9
Views: 2682

Re: GD77 + MMDVM Host problems

Those MMDVM error messages are nothing to do with the radio or its firmware, they are indicating a problem with your internet connection. The data is arriving too slowly and is resulting in lost data packets and hence lost speech. It could be due to your internet connection or the server you are con...