View Full Version : VX-7R high power on 220mhz?
KE7UAF
07-02-2008, 04:23 PM
I've noticed when using VX-7 Commander it looks like it's possible to change the power output on the 220mhz band up to a full 5 watts. Has anyone tried this? Would it be a bad idea? I haven't tried it yet obviously, I wanted to get a few opinions from people that know more than I do first. And avoid frying my radio. Afterall, it seems like the limit on the power has to be there for a reason, right?
K4WWD
07-02-2008, 04:32 PM
Don't know if I understand the question.... isn't it 5W out of the box..??
http://www.rigpix.com/yaesu/vx7r.htm
k2jnc
07-02-2008, 10:52 PM
Don't know if I understand the question.... isn't it 5W out of the box..??
http://www.rigpix.com/yaesu/vx7r.htm
The VX-7 is 0.3 watts on 220 MHz, I believe.
And 1 watt on 6 meters...
It is 5 watts max on 2m/70cm.
The VX-6 also has the same limitations with 220 MHz.
The VX-7 is 0.3 watts on 220 MHz, I believe.
And 1 watt on 6 meters...
It is 5 watts max on 2m/70cm.
The VX-6 also has the same limitations with 220 MHz.
The VX-6 output on 220 is 1.5 watts.
and about .5W on 6 meters (with the mod)
I've noticed when using VX-7 Commander it looks like it's possible to change the power output on the 220mhz band up to a full 5 watts. Has anyone tried this? Would it be a bad idea? I haven't tried it yet obviously, I wanted to get a few opinions from people that know more than I do first. And avoid frying my radio. Afterall, it seems like the limit on the power has to be there for a reason, right?
You could try programming it for 5 watts and then check the output with a watt meter. Chances are that it will not put out that much. Also, make sure to use a 220 antenna.
You could try programming it for 5 watts and then check the output with a watt meter. Chances are that it will not put out that much. Also, make sure to use a 220 antenna.
And I would check the output with a spectrum analyzer to boot...
WA9SVD
07-10-2008, 05:30 AM
Where's "Cowthief" when we need him?:p:rolleyes:
Where's "Cowthief" when we need him?:p:rolleyes:
On The Island... (http://www.hamisland.net)
WA9SVD
07-12-2008, 10:22 PM
You could try programming it for 5 watts and then check the output with a watt meter. Chances are that it will not put out that much. Also, make sure to use a 220 antenna.
Actually, a dummy load would be a better choice... WITH the spectrum analyzer in-line.
wd5ccw
07-16-2008, 03:06 AM
There is a modification, but the most wattage that you will get going through 220, is 1 watt.
Just to clarify (page 18 of the manual) 5 watts on 6/2/70cm; .3 on 220 and 1 watt fixed on 6 meter AM.
I have one of the earlier model vx-7r and have been trying to keep up with the mods on it. If you hear different, I want to know!
XU7ADQ
08-14-2008, 12:00 PM
The VX-6 output on 220 is 1.5 watts.
and about .5W on 6 meters (with the mod)
The version available here is 5W on 50/144/430 straight out of the box, and 220 at 1.5W with the mod.
So now I've got a nice quad-bander for $250 in Phnom Penh, and the supplied antenna is the one with the "top blob" for 6 meters.
Strange that Yaesu make different models for Asia?
See yer
Paul
:)
zl3gsl
09-01-2008, 04:42 AM
The usual reason for a manufacturer setting sets for lower power on higher frequencies is that they want the sets to last for the period of the guarantee. :D The finals often work less efficiently at higher frequency, so they run hotter, and ... :(
Manufacturers make different models for different markes because the bandlimits differ between the markets.
WA9SVD
09-01-2008, 05:38 AM
And I would check the output with a spectrum analyzer to boot...
hasn't anyone ever heard of a dummy load? :confused:
zl3gsl
09-03-2008, 07:46 AM
a spectrum analyzer to boot...
Fill a boot with salt water and put two wires in it. One dummy load. :cool:
The usual reason for a manufacturer setting sets for lower power on higher frequencies is that they want the sets to last for the period of the guarantee. :D The finals often work less efficiently at higher frequency, so they run hotter, and ... :(
Following that logic it would run even hotter at 440 mhz and have even less power, however thats not the case..
zl3gsl
09-16-2008, 05:21 AM
Another reason for a lower power might be to ensure that the transmissions comply with the regulations. Perhaps a 5W "220 MHz" is giving 2W at 440MHz, and another 1W at 660MHz. ;)