[greggold]

I also experienced radio signal issues today with my Tx16s, but there was no loss of control. Rather I had more jumps in tx power (TPWR) today than usual. My RM Tx12 tx (set to dynamic power on) has a minimum default of TPWR of 25 mw and has less frequent jumps. I am doing a comparison flying the same model using the Tx16 and Tx12 on alternate flights.

I posed this question several says ago on Discord Help and Support and I got some responses including from an expert V-22. My Discord user name is Gregor. This link may access the full conversation:
https://discord.com/channels/59635002219...2615555074

Title:  Dynamic power range on a Radiomaster Tx16s

Is there a way to adjust the dynamic power range on a Radiomaster Tx16s?
I am using edgetx 2.7.1, ands elrs 3.0.1
Packet rate 100Hz full, telem ratio Std (1:32).
At my noisy flying environment the tx defaults to minimum TPWR 10 mw on startup and model launch, but there are frequent jumps to 25 mw, and occasional ones to 50 or 100 mw.
My RM Tx12 has a minimum default of TPWR of 25 mw and does not have frequent jumps.
Can I adjust the Tx16s dynamic range so there is a minimum of 25 mw?

Some points are:
For aircraft a packet rate of 100 Hz full is recommended with telem ratio of 1:32. V-22 says a telem ratio Std (1:32) is fine, it means "Link stats frames are sent ~2x/second, and 1:32 at 100Hz should give you ~3 telemetry frames per second." This means at lower packet rates you can use  better telemetry ratios (1:32) providing more frequent updates for the tx which means quicker power jumps when required, eg interference causes the receiver signal to noise ratio to fall.

A post by sunjun (screenshot attached) says it is easy to adjust the  minimum default of TPWR of 10mw on the Tx16s to 25 mw. V-22 says jumps are a sign the Tx16s is working properly, and there is no need to worry.

This discussion of dynamic power is useful:

https://www.expresslrs.org/software/dyna...mit-power/

I will add some flight logs in a subsequent post.

[caffeine]

Interesting, I'm at 100Hz packet rate with a telemetry ratio of 1:16. The info about faster telemetry updates leading to more responsive dynamic power is useful.

[greggold]

I also experienced radio signal issues today with my Tx16s, but there was no loss of control. Rather I had more jumps in tx power (TPWR) today than usual. My RM Tx12 tx (set to dynamic power on) has a minimum default of TPWR of 25 mw and has less frequent jumps. I am doing a comparison flying the same model using the Tx16 and Tx12 on alternate flights.

I posed this question several says ago on Discord Help and Support and I got some responses including from an expert V-22. My Discord user name is Gregor. This link may access the full conversation:
https://discord.com/channels/59635002219...2615555074

Title:  Dynamic power range on a Radiomaster Tx16s

Is there a way to adjust the dynamic power range on a Radiomaster Tx16s?
I am using edgetx 2.7.1, ands elrs 3.0.1
Packet rate 100Hz full, telem ratio Std (1:32).
At my noisy flying environment the tx defaults to minimum TPWR 10 mw on startup and model launch, but there are frequent jumps to 25 mw, and occasional ones to 50 or 100 mw.
My RM Tx12 has a minimum default of TPWR of 25 mw and does not have frequent jumps.
Can I adjust the Tx16s dynamic range so there is a minimum of 25 mw?

Some points are:
For aircraft a packet rate of 100 Hz full is recommended with telem ratio of 1:32. V-22 says a telem ratio Std (1:32) is fine, it means "Link stats frames are sent ~2x/second, and 1:32 at 100Hz should give you ~3 telemetry frames per second." This means at lower packet rates you can use  better telemetry ratios (1:32) providing more frequent updates for the tx which means quicker power jumps when required, eg interference causes the receiver signal to noise ratio to fall.

A post by sunjun (screenshot attached) says it is easy to adjust the  minimum default of TPWR of 10mw on the Tx16s to 25 mw. V-22 says jumps are a sign the Tx16s is working properly, and there is no need to worry.

This discussion of dynamic power is useful:

https://www.expresslrs.org/software/dyna...mit-power/

I will add some flight logs in a subsequent post.

Flight signal issues today.

I compare flight logs of a single 3D plane at PRCAC field today, one flight with the RM TX16s tx and the other with a Tx12. Both flights use elrs with dynamic power turned on. Packet rate is 100 Hz and telemetry ratio is set to 1:32.

Both flights are a bit over 5 minutes. Notice that most of the parameters are divided by 2, so a value of Tx power (TPWR) of 50 on the graph means 100 mw. There are jumps from 10 mw to 25, to 50, and several jumps to 100 in the Tx16s flight, more than I have previously experienced. I only had 1 jump in all my Tx12 flights, and none in the Tx12 log shown..

Notice that there are 2 RSS (receiver signal strength values), as I am using a RM ER6 rx which has 2 antennas (it is not a true diversity rx). Throughout both flights the RSS and RQly (receiver quality, also known as valid frame rate and link quality) remain at normal levels. Thus RQly remained at 80 or above, and RSS did not go below -80.

The main feature is how low the receiver signal to noise ratio (RSNR) is in the Tx16S, compared to the Tx12. Check and compare the number of measurements that are under 5 (this means the number of measurements that fall under the 10 gridline). In the Tx12, only one measurement was under 5, compared to a large number in the Tx16s.  However a value as low as 1 is acceptable if you are using a lower packet ratio. The Tx16s had 8 measurements of RSNR of 0 or below 0, and this is a trigger for a power jump.

I have many similar logs that show the above difference between the Tx16s and the Tx12. This supports the idea that its the base value of dynamic power of 10 mw on the Tx16 (compared to 25 on the Tx12) that causes the lower RSNR values on the Tx16. I have not yet decided whether it is a good idea to change the base value of dynamic power on the Tx16s to 25mw, as discussed in the previous post.

[greggold]

I have posted again in Discord asking for more info on the method sunjun proposed to raise base dyn power on the Tx16s

[greggold]

Those who have looked at this thread know that I have been considering changing the minimum value of the dynamic power range on my Tx16 from 10mw to 25mw. This idea comes from comparing flight logs of my Tx16 to flight logs on the same models taken with my Tx12 (min value 25mw), and also comparisons to Boxer (min value 25mw) flight logs. ]

The Tx16 works perfectly well indeed I have had no control loss incidents. However, the txs with a 25 mw minimum appear to have a higher rx signal to noise and slightly better rx link quality (aka valid packet rate), and fewer power jumps with the dynamic power setting. I now plan to make some analysis of a large number of logs to quantify this finding.

When I posted my question on this topic on Discord, I had responses from 2 people who work on an expert panel that provides responses to elrs help requests.
The above discussion on Discord is located here. https://discord.com/channels/59635002219...2615555074

I decided to do what Sunjun suggested, but I failed as follows in a further Discord post:
I tried to "increase the minimum power of your module, by accessing 10.0.0.1/hardware.html on TX's WiFi mode". I ran elrs lua script, selected tx wifi, got an elrs window in my browser that identified my tx as having elrs v 3.3.0, but in the options, wifi or update menus there was nothing about hardware.

Yesterday Sunjun offered further advice:
"locate to http://10.0.0.1/hardware.html
insert that address directly"

I plan to check out this hardware menu which is completely new to me.

In case you cannot locate the relevant Discord posts, Sunjun says:

Remove the first value in the Level Values list.

[-17,-13,-9,-6,-2] so it looks like [-13,-9,-6,-2]

Increase Min Power from 10mW to 25 mW

[caffeine]

I see the described fields on my TX16S when I go to that address.

   

[greggold]

I agree, I can find the hardware website, the question is should I change it? Having thought about this for quite a while I am inclined to do so. I trust sunjun as an elrs expert who handles tough questions about elrs on Discord. Even if my Tx16 has no problem of signal loss on 10mw, if I can improve the rc signal I think its always worth doing.

The risk seems small, and if I try it and don't like the 25mw baseline, there is no reason I cannot simply change it back, as far as I can tell.

The main reason I have not done it is I planned to first clarify how much better the signal is with baseline 25mw, by ploughing through my large collection of logs using planes that are flown with both my tx12 (25mw baseline) and my tx16, at a high noise field (prcac) and a low-noise one (a local oval). This job is keeping me busy as I do not have the analytic framework sorted yet. I know already I can easily tell which log plot is 25mw baseline, and which is 10mw, even without plotting the TPWR data, with the difference more apparent at prcac.

Here is a simple framework I may use, based on the occurrence of these parameters for 0.5 sec or more, whether once or multiple times in a flight. Each flight is categorised:

high quality rc signal flight: RQly>98, RSNR>6, no TPWR jumps (all values for 3 parameters must conform)

low quality: RQLY <96, RSNR<1, TPWR jumps (only needs one parameter to qualify as low)

medium quality: does not fit high or low category.

[greggold]

Today 23 Sept I had 2 flights on my Superextra 1m, one with my Tx12 tx and one with my Tx16s. The SuperExtra has a RM ER6 rx, and over many flights there has never been a control problem. However the appearance of the flight log when its flown with the Tx16s continues to concern me. I attach the 2 logs from today, one is called Superext12 and the other SuperExtra16 with the tx in the plot name.

Comparing the 2 logs, the Tx12 has a better signal quality throughout, based on RQly, RSNR, and RSSI. Looking at the Superext16 plot, you see the tx power TPWR has a baseline 10mw, but there are around 9 jumps in Tx power, including one to 100mw lasting 2-3 secs at 90 seconds. The Tx12 log has no jumps, meaning at no time did the tx detect a potential danger of signal loss. The 12 log had a higher RQly, remaining at 98-100 throughout, while the Tx16 log dropped below 90 on 5 occasions.

The RSNR is clearly lower in the tx16 log. While the tx12 RSNR remains mostly above 10, the tx12 has some zero values and other values below 1-2. Finally the RSSI is better in the tx12, with many values higher than -60 db, while the tx16 its mostly below -60db.

I have detected no evidence of a fault in my Tx16s, rather the lower signal quality manifest today appears to relate to the lower baseline TPWR. I will be changing my Tx16 baseline soon to 25mw  to see if it confirms this theory.

I would be interested in comparing flight logs from other Tx16 flights. If you send me a Tx16 csv flight log, I will be happy to plot it. I am working to make a detailed analysis of many of my flights.

[greggold]

Here is another comparison of a flight with a tx with 10mw minimum dyn power (Tx16), compared to a tx with 25mw min dyn power (Tx12). The plane is a superlite crack yak (TW), a 80 cm span 3D plane, a 2S lipo, with a R24-P6 rx. Planes like this virtually never have control signal problems, but it is interesting to check if there is an indication that the higher minimum TPWR of the T12 is associated with a stronger signal.

Both plots have no TPWR jumps: TPWR remains at 10mw throughout the flight for the Tx16, compared to 25 for the T12.

Both plots show excellent radio signal throughout, however there is evidence that the T12 plot has:
-  generally higher signal to noise ratio, with only 3 values of 10 or less. This compares to 14 values of 10 or less in the T16 plot, with one value as low as 4.
- the Tx16 plot has fewer values of RSSI<60, compared to many values of RSSI<60 in the T12 plot.

I should emphasise I have experienced no signal problems with the Tx16, and the purpose of this exercise is to show whether the signal can be improved by adopting a higher baseline for dyn power. I would be interested to compare plots with other Tx16 owners who fly 3S lipo planes, to show my experience with plots of Tx16 flight  logs is not atypical, and I can prepare a plot if sent a csv log file.

[greggold]

Here is another comparison of a flight with a tx with 10mw minimum dyn power (Tx16), compared to a tx with 25mw min dyn power (Tx12). 

A top elrs authority CapnBry  has done an excellent post on the question of the minimum value for dynamic power range on the Tx16s:

https://www.rcgroups.com/forums/showthre...em/page159

This was posted in response to an earlier  post I did called "Effect of Baseline Dynamic Power on Signal Safety" that showed that if the minimum value of the range was 25mw compared to 10 mw, you would have far fewer power jumps.

https://www.rcgroups.com/forums/showthre...em/page157

I had argued that a power jump was associated with less safety for the radio signal, to which CapnBry says "A power jump doesn't mean a failsafe almost happened, not even close." However he says you can change the minimum to 25 if you want, and he repeats sunjuns method to do this. So I will be doing this, as now there are convincing statements from 2 experts that this is fine to do.

[greggold]

Today I changed my tx16s baseline dynamic power from 10mw to 25mw, as detailed above. It was easy to do. When I went to  http://10.0.0.1/hardware.html (as discussed above in post #5 and following) the tx settings were shown (attached). After making the changes I clicked save at the bottom of the screen and now when I check the telemetry the baseline is 25 mw. 

I now routinely save logs and add to my data base of RSSI, RQly, RSNR and TPWR values (with practice this is quick to do). I will soon be able to compare the Tx16s and Tx12 after this change, and I expect the 2 txs will now show the same performance. I will carefully evaluate any effects of the change.

My reason for making this change is explained in a post I did on RCGroups called "Effect of Baseline Dynamic Power on Signal Safety" that showed that if the minimum value of the range was 25mw compared to 10 mw, you would have far fewer power jumps, and fewer low values of RSNR and RQly.

https://www.rcgroups.com/forums/showthre...em/page157