The relay needs to know when to activate to by-pass, how will you do that ? Even if you manage to figure this out, it will not work on DMR because of Timeslots. Relays cannot switch that fast (that's why you can't use linear amps on DMR either for Tx)
our second CB service in Aus is 80 ch @ 12.5khz steping on the 63 cm band (476.425 - 477.4375) with a few jump ch's, we are allowed 5wts with a 6dB co-linear vertical ant, but a lot of hick operators use 100 -200 wts with 15 - 16 -17 ....etc element yagi-udo beams, (log is around 15-16 dB??)I bought 2X80wt-out (input 5wts) @ $130AU each similar to this DMR Digital Amplifier, with the pre-amp(Rx), I run them on 2x home built 17 elements beams and get good reports (50-100+ kms) around sydney depending on terrain we have repeaters (chs1-8/41-48 +offset 0.750khz) ..just a a little silly trivia as we say ....its just radio ..p.s. its only FM
I also would like to know if you have tried your relay solution that you mention in the video on a DMR hotspot. Maybe you can do a video on how to build that.
Bought one like this that now has the switching diodes that allows receive signal to pass through. The bad thing is when I powered it up it whistled for 30 seconds and quit. No transmit. Nothing shorted. Diodes are good.
Fixed it.. It wasn't switching on the 3.4V regulator that applies power to the Vg pin on the module. Turned out the cor sense diodes were bad. I replaced them with some old radio shack 5082 schotky diodes I had on a card from Phone Shack. Thousands of dollars in parts in stock and I've gotta reach for a radio shack card for uhf diodes. Anyway it works with my PI-Star MMDVM HS hat board. Dont' have a wattmeter on it but Its pulling some current and with the mobile whip on a computer case I can go about 1/2 mile from the shop.. Metal roof on the shop so.. pretty shielded.. .. Again this later version has the 1/4 lines and shunting diodes that keep the output from backfeeding during transmit.. .
Hi AirWavZ, Would a relay work? They're pretty slow acting ... too slow for operating at timeslot speeds. Also, wouldn't there be a burst of Amplified RF back into the output stage of the transceiver each time you key up? 8W into a 20mw output stage, even for a moment, doesn't sound very healthy. Have you tried this? What were your results? M6UDS
Ok, show us the link and provide the test video, all mmdvm hotspots i have seen nax out a 10mw. Would that even trigger some other amp. Everything else says 20mw minimum even though these 20mw amps are titled "FOR MMDVM HOTSPOTS". I NEED PROOF!
Perfect for a Duplex hotspot; cool!
The relay needs to know when to activate to by-pass, how will you do that ? Even if you manage to figure this out, it will not work on DMR because of Timeslots. Relays cannot switch that fast (that's why you can't use linear amps on DMR either for Tx)
I think its for dual spots.
This is meant for the full duplex pi star setup.
Thanks for the video, you just saved me $50.00
our second CB service in Aus is 80 ch @ 12.5khz steping on the 63 cm band (476.425 - 477.4375) with a few jump ch's, we are allowed 5wts with a 6dB co-linear vertical ant, but a lot of hick operators use 100 -200 wts with 15 - 16 -17 ....etc element yagi-udo beams, (log is around 15-16 dB??)I bought 2X80wt-out (input 5wts) @ $130AU each similar to this DMR Digital Amplifier, with the pre-amp(Rx), I run them on 2x home built 17 elements beams and get good reports (50-100+ kms) around sydney depending on terrain we have repeaters (chs1-8/41-48 +offset 0.750khz) ..just a a little silly trivia as we say ....its just radio ..p.s. its only FM
I also would like to know if you have tried your relay solution that you mention in the video on a DMR hotspot. Maybe you can do a video on how to build that.
OMG you tapping on that board while it's powered on is giving me OCD haha. Thanks for the warning on this though.
Bought one like this that now has the switching diodes that allows receive signal to pass through. The bad thing is when I powered it up it whistled for 30 seconds and quit. No transmit. Nothing shorted. Diodes are good.
Fixed it.. It wasn't switching on the 3.4V regulator that applies power to the Vg pin on the module. Turned out the cor sense diodes were bad. I replaced them with some old radio shack 5082 schotky diodes I had on a card from Phone Shack. Thousands of dollars in parts in stock and I've gotta reach for a radio shack card for uhf diodes. Anyway it works with my PI-Star MMDVM HS hat board. Dont' have a wattmeter on it but Its pulling some current and with the mobile whip on a computer case I can go about 1/2 mile from the shop.. Metal roof on the shop so.. pretty shielded.. .. Again this later version has the 1/4 lines and shunting diodes that keep the output from backfeeding during transmit..
.
Hi AirWavZ,
Would a relay work? They're pretty slow acting ... too slow for operating at timeslot speeds. Also, wouldn't there be a burst of Amplified RF back into the output stage of the transceiver each time you key up? 8W into a 20mw output stage, even for a moment, doesn't sound very healthy.
Have you tried this? What were your results?
M6UDS
There's a newer version available that does have receive capability.
Ok, show us the link and provide the test video, all mmdvm hotspots i have seen nax out a 10mw. Would that even trigger some other amp. Everything else says 20mw minimum even though these 20mw amps are titled "FOR MMDVM HOTSPOTS". I NEED PROOF!
So you bought it with it saying it doesnt have receive function . what are you complaining about ?
Run it through a directional coupler with two antenna's and it will work
G1LBU can u point to one? I only see $500 insustrial ones
no doesn't have enough to push the transmitter Circuit i've tried it
Nice one :) !!
good for rpitx
Done! ^^ 607
Subbed u back thanks