Setting DM1801 TX Power in Hotspot Mode

K9RPL
Posts: 12
Joined: Tue Apr 07, 2020 1:38 pm
Location: St. Charles IL, USA

Setting DM1801 TX Power in Hotspot Mode

Post by K9RPL » Tue Apr 07, 2020 8:49 pm

I'm trying to set the TX power in a pi-start and no matter what I put in Expert mode the radio comes up at 1W.

The default seems to by Power=1 in the MMDVMHost. I've tried several settings but it always stays at 1W.

Is there a way to get the power down as much as possible that I'm missing?

I'm using pi-star 4.1.0 March 26th 2020 build.

VK3KYY
Posts: 7478
Joined: Sat Nov 16, 2019 3:25 am
Location: Melbourne, Australia

Re: Setting DM1801 TX Power in Hotspot Mode

Post by VK3KYY » Tue Apr 07, 2020 9:08 pm

What settings did you try in PiStar and on the radio?

K9RPL
Posts: 12
Joined: Tue Apr 07, 2020 1:38 pm
Location: St. Charles IL, USA

Re: Setting DM1801 TX Power in Hotspot Mode

Post by K9RPL » Tue Apr 07, 2020 9:35 pm

Good evening Roger!

Well the default value in the pi-star is Power=1 and I've tried .5, 50 ,50% etc..

As for the radio. The menu isn't available in hotspot mode but I have a feeling I should have set the power *before* putting it into Hotspot mode.

Chuck
K9RPL

VK3KYY
Posts: 7478
Joined: Sat Nov 16, 2019 3:25 am
Location: Melbourne, Australia

Re: Setting DM1801 TX Power in Hotspot Mode

Post by VK3KYY » Tue Apr 07, 2020 9:42 pm

BTW. Its the site policy for everyone to use their callsign as their username, where possible, so I have changed your username to K9RPL

Unless there is a bug, the power for the radio should be able to be set via the Expert settings in PiStar

AFIK the acceptable values in PiStar are 1 to 100

However, if you leave the power set to 100 in PiStar, it uses the power you have set in the radio, and the default is 1W

The reason we do not use 100% = full power, is that many people don't understand how to configure PiStar to set the power, and would end up running the hotspot at 5W, which the radio hardware is not designed to do, as its not intended to have such a high duty cycle

K9RPL
Posts: 12
Joined: Tue Apr 07, 2020 1:38 pm
Location: St. Charles IL, USA

Re: Setting DM1801 TX Power in Hotspot Mode

Post by K9RPL » Tue Apr 07, 2020 9:50 pm

Well, I got it. I need to set the power *before* going into hotspot mode. The OpenDM1801 docs are is a little hazy on that and I interpreted it as the pi-star would set the power.

Looks like I'm good to go.Running at 50mW.

Sorry about the username foul up. I usually use my call. Missed that one too I guess! Thanks for changing it for me!

Chuck

VK3KYY
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Joined: Sat Nov 16, 2019 3:25 am
Location: Melbourne, Australia

Re: Setting DM1801 TX Power in Hotspot Mode

Post by VK3KYY » Tue Apr 07, 2020 10:03 pm

You should be able to set the power in PiStar.

The software should try to set it to the step value closest to the value you selected.

i.e 1% should set the radio into 50mW, but there is always a chance that there is now a bug in this functionality

K9RPL
Posts: 12
Joined: Tue Apr 07, 2020 1:38 pm
Location: St. Charles IL, USA

Re: Setting DM1801 TX Power in Hotspot Mode

Post by K9RPL » Tue Apr 07, 2020 10:09 pm

Ah ha! So I'm *not* crazy!

The current default is power=1 in pi-star so that should have set it to 50mW.

No worries though. Not what I'd call a big deal. Easily remedied.

VK3KYY
Posts: 7478
Joined: Sat Nov 16, 2019 3:25 am
Location: Melbourne, Australia

Re: Setting DM1801 TX Power in Hotspot Mode

Post by VK3KYY » Tue Apr 07, 2020 10:17 pm

No.

Sounds like you are not crazy after all.

BTW. You can't measure power in DMR mode, so I'm not sure how you were testing this.
I don't know of any power meter that can handle DMR pulsed emissions.
AFIK. Commercial radios like Motorola mobile units have a special test mode for setting the RF power, which transmits a clean carrier.

K9RPL
Posts: 12
Joined: Tue Apr 07, 2020 1:38 pm
Location: St. Charles IL, USA

Re: Setting DM1801 TX Power in Hotspot Mode

Post by K9RPL » Tue Apr 07, 2020 10:21 pm

I wasn't measuring the power. Just hoping the power level displayed by the radio is at least in the ballpark.

VK3KYY
Posts: 7478
Joined: Sat Nov 16, 2019 3:25 am
Location: Melbourne, Australia

Re: Setting DM1801 TX Power in Hotspot Mode

Post by VK3KYY » Tue Apr 07, 2020 10:34 pm

umm

The display may not be updating.

I've not checked the code recently

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