You can run "./qnconfig expert" and that will give you access to many other values, including the TX power in the modem.

Be careful in this "expert" mode, you can really screw things up.

On Sat, Feb 13, 2021 at 05:42 AM, Tom Early wrote:

You can run "./qnconfig expert" and that will give you access to many other values, including the TX power in the modem.

Be careful in this "expert" mode, you can really screw things up.

I'm seeing "Transmit level (0-255)". Even cutting this just in half is making things non-functional. I suspect it's not doing what I expected it would when cutting transmit power in half. Is 64 not half of the default of 128?

I would be really surprised if this parameter was linear with power (or linear with voltage). I suggest you decrement in smaller steps and explore the response that way.

I also wouldn't be surprised if the spurious output of the transmitter changed with this setting. You might want to ask KI6ZUM. He probably knows.

Keep in mind that when you configure MMDVMHost, like in Pi-Star, takes a floating point number in the range of 0.0 to 100.0 then it scale that number to an 8-bit (1-byte) number (0-255) before setting it into the device, while with QnetModem, the range is 0-255. In MMDVMHost, the default value is 50, so I set the default value in QnetModem to 128.

On Sat, Feb 13, 2021 at 11:30 AM, Tom Early wrote:

I would be really surprised if this parameter was linear with power (or linear with voltage). I suggest you decrement in smaller steps and explore the response that way.

I also wouldn't be surprised if the spurious output of the transmitter changed with this setting. You might want to ask KI6ZUM. He probably knows.

Turns out that "transmit level" is not what I'm after. I'm wanting to set the "RF level". But the RF level setting is not available in the expert modem settings in QnetGateway. The RF level is available in the expert settings in both Pi-Star and DOH. Any chance you could make it available in QnetGateway?

RF Level is now available in the "./qnconfig expert" menu. The default value is 255 (100%) and the range is 0 to 255. I have no idea how linear this parameter is for any given modem.

Of course this is only for the "mmdvmmodem" modem type (used for MMDVM modems operating in "DStar-Only mode"). If you are using the "mmdvmhost" type modem, then you are running MMDVMHost along side of qngateway, qnlink and qnrelay and you would control RF Level with your MMDVM.qn config file.

Sorry this took so long. Several files had to be changed.

P.S. I'm taking a "summer vacation" that isn't so much about ham radio and so my response time is much slower than normal and my code production is also down. I will get back to more normal activity levels sometime in September.

On Thu, Jul 8, 2021 at 12:13 PM, Tom Early wrote:

RF Level is now available in the "./qnconfig expert" menu. The default value is 255 (100%) and the range is 0 to 255. I have no idea how linear this parameter is for any given modem.

Thank you Tom. I may not be able to try this until next week. I think the default value I've seen in DOH and Pi-Star was 100. I thought the valid range was 1-100. But I could easily be mistaken. I will let you know how it goes. Thanks again.?

开云体育

Yes. MMDVMHost (and DOH) use a floating point value from 0.0 to 100.0, which they then convert into an unsigned character with a range from 0 to 255 that the modem firmware expects.

The QnetGateway software is a little closer to the modem firmware, at least in this case.

On Thu, Jul 8, 2021 at 12:13 PM, Tom Early wrote:

RF Level is now available in the "./qnconfig expert" menu. The default value is 255 (100%) and the range is 0 to 255. I have no idea how linear this parameter is for any given modem.

Thank you Tom. I may not be able to try this until next week. I think the default value I've seen in DOH and Pi-Star was 100. I thought the valid range was 1-100. But I could easily be mistaken. I will let you know how it goes. Thanks again.?

-- 
___________________________
73
n7tae (at) tearly (dot) net

On Thu, Jul 8, 2021 at 12:41 PM, Tom Early wrote:

Yes. MMDVMHost (and DOH) use a floating point value from 0.0 to 100.0, which they then convert into an unsigned character with a range from 0 to 255 that the modem firmware expects.

The QnetGateway software is a little closer to the modem firmware, at least in this case.

Fantastic. Thank you for the extra info. I am anxious to give it a go. I have a veritable hotspot farm in my shack. So reducing power to the minimum necessary is desirable to reduce interference (at least in my mind).?

开云体育

I think that's one of the golden rules of ham radio, isn't it? Use the least power necessary to get the job done.

On Thu, Jul 8, 2021 at 12:41 PM, Tom Early wrote:

Yes. MMDVMHost (and DOH) use a floating point value from 0.0 to 100.0, which they then convert into an unsigned character with a range from 0 to 255 that the modem firmware expects.

The QnetGateway software is a little closer to the modem firmware, at least in this case.

Fantastic. Thank you for the extra info. I am anxious to give it a go. I have a veritable hotspot farm in my shack. So reducing power to the minimum necessary is desirable to reduce interference (at least in my mind).?

-- 
___________________________
73
n7tae (at) tearly (dot) net

On Thu, Jul 8, 2021 at 12:46 PM, Tom Early wrote:

I think that's one of the golden rules of ham radio, isn't it? Use the least power necessary to get the job done.

Yep, an actual FCC regulation I think. :) ?And good news... I set the RF level to 25 and things are working well. I figure that's close to 1/10th of the full power setting. Thanks very much for making time during your sabbatical.?

开云体育

I’m really loving the way this works. ?DO have some “nice to haves” that would be cool if they could be implemented. ?HOw do i send those so you can track them?

I bought a pack of tiny SMA dummy loads that I use on several hotspots.? They still cover my 1/2 acre property, but I don't seem to have any problems with intermod.

On Fri, Jul 9, 2021 at 07:07 AM, Ryan Matthew Headley wrote:

I bought a pack of tiny SMA dummy loads that I use on several hotspots.? They still cover my 1/2 acre property, but I don't seem to have any problems with intermod.

Interesting. That should work pretty well. I guess if I had my choice, I'd prefer to dial back the output power via software. And thanks to Tom's recent changes, now I can!?

Come to think of it... my SHARI Allstar node thingy does not have a power adjustment. I think I will seek out a dummy load for that. Thanks for the tip Ryan.