Search found 124 matches

by ve7mdt
Mon Jan 30, 2023 9:00 am
Forum: General discussions
Topic: FM APRS function
Replies: 19
Views: 3504

Re: FM APRS function

n6io wrote:
Wed Jan 11, 2023 12:35 am

It shouldn't be difficult to have OpenGD77 send APRS but without a GPS it's not very useful.

Craig - N6IO
The TYT MD-UV380 and the TYT MD-9600 both can have GPSr, and plus the OpenGD77 firmawre supports the GPSr functionality.

So why are you saying "without a GPS..."?
by ve7mdt
Mon Jan 30, 2023 8:17 am
Forum: TYT MD-UV380 / UV390 / Retevis RT-3S
Topic: FYI - GPS
Replies: 34
Views: 2556

Re: FYI - GPS

Nope. GPS orbital plane inclination is 55 degrees - so for 40-ish degrees latitude most of the satellites are to be found somewhere more or less towards the equator. Also there is a bunch of QZSS and GEO/GSO BeiDou satellites visible here in Asia/Australia - which are again located more or less tow...
by ve7mdt
Sat Jan 07, 2023 12:06 am
Forum: TYT MD-UV380 / UV390 / Retevis RT-3S
Topic: FYI - GPS
Replies: 34
Views: 2556

Re: FYI - GPS

I think the 24 GPS satellites (except the WAAS special purpose ones) fly in all kinds of paths in space and thus no need to orient it toward "north" from the southern hemisphere. It should work globally and thus the namesake. Nope. GPS orbital plane inclination is 55 degrees - so for 40-ish degrees...
by ve7mdt
Mon Dec 19, 2022 8:14 am
Forum: TYT MD-9600 / Retevis RT-90
Topic: TYT MD-9600 discontinued?
Replies: 11
Views: 1886

Re: TYT MD-9600 discontinued?

There are TYT MD-9600s available right now on Amazon in the US. They are being sold by a vendor called KITOOPS. I have no affiliation with this seller or Amazon. https://www.amazon.com/dp/B07JJWKPCF I can confirm they are V5 radios and work great with OpenMD9600. It says unavailable as of now , whi...
by ve7mdt
Mon Dec 19, 2022 7:33 am
Forum: Off topic
Topic: TYT MD-9600, add GPS later?
Replies: 25
Views: 1497

Re: TYT MD-9600, add GPS later?

Great work, Roger. The reason for the RS-232 signal is that it can travel much further in a cable w/o problem while a TTL signal is very susceptable to degradation of the signal quality over long distance. Most external GPSr back in the days are all RS-232 signalling. I still own modules that are mi...
by ve7mdt
Tue Nov 29, 2022 1:46 am
Forum: Off topic
Topic: Retevis One-Day Sale 11/11
Replies: 1
Views: 183

Re: Retevis One-Day Sale 11/11

I just noticed that they have a Black Friday sale (for the US). I haven't checked the price on this model, but I was looking for the RT-90 and it's $280 w/ GPSr and $270 w/o. I haven't checked shipping cost yet.

Another source is retevissolutions.com, and I am not sure if they are related or not.
by ve7mdt
Tue Nov 29, 2022 1:43 am
Forum: Off topic
Topic: Call Sign "Shershen"
Replies: 4
Views: 393

Re: Call Sign "Shershen"

may be that is a fighter pilot's callsign?
by ve7mdt
Tue Nov 29, 2022 1:42 am
Forum: Off topic
Topic: TYT MD-9600, add GPS later?
Replies: 25
Views: 1497

Re: TYT MD-9600, add GPS later?

This is an interesting mod. My Kenwood TM-D710A (not the G model) has a 2.5mm jack on the control head to connect to an external (not included) GPS (signal). Some people modified the head to bury it internally, but the antenna does not face up so it's not ideal. (The GA model has it built in inside ...
by ve7mdt
Fri Nov 18, 2022 3:09 am
Forum: General discussions
Topic: FM APRS function
Replies: 19
Views: 3504

Re: FM APRS function

Do you have a link to the modulation standard for this ? e.g. what tone frequences are used to define logic 1 and 0 ? Sorry, Roger, I haven't been back to this forum lately and missed your post. I haven't looked at any implementation of the Bell 202 modem or 1200 AFSK packet radio, but I know it's ...
by ve7mdt
Thu Oct 20, 2022 4:34 pm
Forum: General discussions
Topic: gd-77 HT vs md-uv380 performance
Replies: 10
Views: 723

Re: gd-77 HT vs md-uv380 performance

ok, for what its worth here are the measurements for my RT3s , and my DM1801: RT3S: VHF 146.000Mhz , TX 6.33W rx sq open 0.2 uV ( -121dbm) loss of signal 0.134 uV (- 124.5bdm) UHF446.000Mhz, TX 5.3W rx sq open 0.25 uV ( -119dbm) loss of signal 0.23uV ( -119.8 dbm) DM-1801 VHF 146.000Mhz , TX 5.3W r...