My original post below has stimulated allot of controversy and posts. I stand
by what I already said:
.....I've tested the rig extensively at 175 watts on CW and RTTY and have
suffered no component failures, overheating, etc. and no transmit spectral
degradation. Of course like all mods. make it at your own risk.....
I look at it this way. In the original spirit of ham radio I'm not afraid to
open up my modern expensive rice box, to experiment and modify. In my original
post I never mentioned operating my V Field at 200 watts but it did hold up
very well with no overheating etc. at 175 watts on CW and RTTY, as an
experiment. Why did it hold up so well? It's because the rig is better
engineered and has better specs. then advertised and a certain amount of
"appliance operator" headroom is built in.
Am I stressing the rig? Maybe so but if it blows up I'll fix it and/or buy
another one. One ham posted in response to my original post, to paraphrase,
"Real Ham's understand how electronics work and don't turn up the power on
their rig". I say "Real Ham's" are not afraid to experiment.
In any event, in my day to day operations I never run my V Field above 125
watts. I originally tweaked up the power output because from the factory my V
Field only put out 90 watts on 160 meters and I needed 125 watts to drive my
old linear to 800 watts.
73,
Thomas F. Giella, KN4LF
Plant City, FL, USA
Grid Square EL87WX
Lat & Long 27 58 31 44N 82 09 51 98W
PODXS 070 PSK31 Club Member #349
KN4LF Solar Space Weather & Geomagnetic Data Archive:
http://www.kn4lf.com/kn4lf5.htm
----- Original Message -----
From: Thomas Giella KN4LF
To: a Yaesu E-Group ; a 1000MP QTH e-List ; FT-1000MP@yahoogroups.com
Sent: Monday, August 02, 2004 6:28 PM
Subject: Mark V Field Power Output Mod
Justin et all,
The Mark V Field power modification is simple but it will attract naysayers
that will warn of power supply damage/failure, finals failure, degraded
transmitted spectral purity, etc.
Pop the top and bottom covers. Gently turn the rig upside down on a hard
surface with the front of the rig facing you. There are three boards visible.
One is the "Control" board on the left side, the "AF" board on the back right
side and the "IF/Filter" board on the front right side. Go to VR3003 on the AF
board and turn it clockwise. It's marked "RF Power" (I think it was). Fully
clockwise gives you 190 watts in the CW mode on 14200 kc, 200 watts on 1845 kc
and 180 watts on 28400 kc. Of course connect an antenna with low VSWR or a good
dummy load.
I've tested the rig extensively at 175 watts on CW and RTTY and have suffered
no component failures, overheating, etc. and no transmit spectral degradation.
Of course like all mods. make it at your own risk.
---
Outgoing mail is certified virus free by Grisoft AVG 6.0.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.734 / Virus Database: 488 - Release Date: 8/4/2004
_______________________________________________
Yaesu mailing list
Yaesu@contesting.com
http://lists.contesting.com/mailman/listinfo/yaesu
|