VSWR on V16

The expanding range of MGL's innovative RF avionics
Forum rules
Please keep your posts friendly and on topic. No politics or discussions of a controversial nature not related to our favorite subject of flying and avionics. Offending posts may be removed or moderated.
Post Reply
royerm
Posts: 29
Joined: Sun Feb 06, 2022 1:43 pm

VSWR on V16

Post by royerm »

So here it is....

I have cut my coax for 126.700 Mhz and must of done a good job as it is showing 1.0 for VSWR.
If I check at either 118.000 Mhz or 134.00 Mhz I get 1.2 for VSWR.
So far so good, I have noticed that at that VSWR (1.0) it's outputting around 5 watts,
and for the other freq. at VSWR 1.2 it's outputting +- 8.6 Watts.

I have 10W selected, but I thought better the match was the more output it would make,
Does the output get cut for the better match it has like the VSWR 1.0????

Regards. :roll: :roll:
rainier
Site Admin
Posts: 703
Joined: Fri Aug 28, 2020 7:03 pm

Re: VSWR on V16

Post by rainier »

Check your supply voltage during transmit - it appears your voltage is dropping quite a bit. That reduces RF power considerably. Measure at the pins of the DB25 connector (both ground and supply).

A V16 typically produces 11 to 12W of RF power at 13.8V provided your load at the RF frequency is 50 ohms - higher or lower and it reduces. The V16 measures the actual power absorbed by the load - SWR shows effectively how much power is reflected. So either you have a low supply voltage during transmit (the radio needs up to 3A) or you have a load that is not 50 ohms - that is possible even if your SWR shows a low number.

Rainier
royerm
Posts: 29
Joined: Sun Feb 06, 2022 1:43 pm

Re: VSWR on V16

Post by royerm »

Rainier..
You were right, my battery was down to 12V.
Regards

Michel
Post Reply