[chirp_devel] VX-7r: power levels for 1.25m band

[David Griffith]

On Wed, 9 May 2012, Dan Smith wrote:

>> The Yaesu VX-7r supports L1 and L2 power settings for the 1.25m, but for
>> some reason Chirp will not accept L2 for that band.  Looking at the code
>> in chirp/vx7.py I see where the check is made and L2 should be accepted.
>> I cannot figure out why this check refuses to accept L2.  The workaround
>> is to manually reset the power level to L2 and re-save.  Has anyone else
>> tried to fix this?
>
> Nope, I had it in the queue. Now that you asked, I looked and I see the
> problem. Skipping down:
>
>> Looking again at chirp/vx7.py, I see statements that look
>> like this:
>>    chirp_common.PowerLevel("L2", watts=0.30)
>> What does that "watts=0.30" mean for the rest of Chirp?  Will that
>> interfere with the power mod mentioned above?
>
> The reason we tie an actual signal level (in watts or dBm) to a
> PowerLevel is so that during import or copy/paste, we can attempt to
> select a similar power level on an incompatible radio based on the
> available power levels. The problem here is that the VX7 driver declares
> to the outside world the main list of power levels. That means that when
> the user selects L2, it passes the 1-watt L2 power level into the
> validate operation, and the driver balks at the request for a power
> level not supported on 220.
>
> There are two options here:
>
> 1. You can declare the 220 L2 to be the same power as that of the main
>   list and then the comparison will succeed. The potential for error
>   here is very minor and I think intentionally misrepresenting the 220
>   power levels are unlikely to cause anyone heartache
> 2. You could change the check to something like this:
>
>   if str(mem.power) not in ["L1", "L2"]:
>       # Fail
>
>   Effectively changing the 220 comparison from absolute power level to
>   by name.

I think this one would be ideal.  I'll work on a patch and post it later 
tonight.

>> Slightly related to this problem, one can modify the VX-7r to boost the
>> transmit power for the 1.25m band.  This is done by entering the factory
>> setup mode.
>
> Interesting. Got a link?

http://wa6plc.info/VX7_220_TX_power.pdf

It's a distillation of the service manual, which is available here: 
http://www.repeater-builder.com/yaesu-vertex-standard/pdfs/yaesu-vx-7r-technical-supplement.pdf

I haven't applied it yet because I want to acquire a wattmeter so I'm not 
flying blind.  Do you have any idea why Yaesu limited 1.25m to such low 
power?

-- 
David Griffith
dave at 661.org