--- In ham_amplifiers@..., Jan Erik Holm <sm2ekm@...>
wrote:
Well right now I dont have any "official test lab" figures,
however W8JI has measured (if you trust him, I do in this
case) -47 dB.
### W8JI, ALSO claimed in the same sentence, -52db for a Drake
T4XC ! I owned 4 of em yrs ago... and I got the same results as
the ARRL lab did... a paltry -30 db pep... or just -26db compared
to one tone... which is typ of sweep tubes. Even to get that,
Drake used 70 ma of zsac @ almost 700 Vdc.... so the idle POWER
on the pair of sweep tubes was = 99% of the rated plate
dissipation !
### What power level did u run the FT-1000D tests at ?? I
currently have 2 x FT-1000D's.... and 2 x FT-1000MP-MK-V's.
haven't measured any of em. Seems to me the arrl lab measured -
36db PEP when then 1000-d was run full bore at 200 w out.
Yaesu claimed -36db, compared to ONE tone [-42 db pep], when run
at 150w out.
### Would be interesting to know what the 1000-D is at say 100
w output ? I'm betting it's very good.
### also... did u drive it into ALC ??? Try setting the power
output at 200 w.... but only driving it to say 190w [no alc]
and then at 150w.... and again at 100 w ..... all the while the
power output control is sitting at 200w.... and no alc ever
showing in any case. Then try it with alc at top of it range.
### Beware,,, my 2 x FT-1000D's new, were totally out of
calibration on every thing...esp alc. Srvc manual sez between no
alc.. and max alc... should be a 9.7 db difference..... mine was
only 5.2 db. {which is better imo... since hams will wail away on
the ALC]
### Also try adjusting the bias pot. I think the normal idle on a
1000-D is just 1 amp. Tweak it up to 1.5 A.... and also 2.0
A... and re-run ur tests.... u will be surprised.
### On the MK-V.... you can adjust EACH transistor
independently.... ditto with the driver transistors.... and you
do all of this TWICE.... once for AB... and again for CLASS A.
### On AB.. idle is 1 A PER final transistor 2A total. On Class
A... it's a whopping 5 A PER transistor... and 10 A total.
### On the MK-V hidden menu 9-XXX... you can also adjust
the "drive" on a band per band basis... most of em are way too
high. On CW... reducing em a bit, will eliminate the key clix.
### To eliminate ALC overshoot on all these rigs... you can
[ssb/cw] apply external -DCV to the ALC jack. You can also
just limit the audio on ssb with external rack mount
compressor's/limiter's/ distortion cancelled audio clippers. That
way, I can achieve an easy 1500w with NO alc ever showing at
all... if u wanted.
R L Measures wrote:
what Ham transceiver will allow testing of IMD below ¨C40db?
### The yaesu MK-V on Class A... depending on BAND... is -60db
for 3rds... and -75db for 5ths. You can hear the diff on a 2nd
RX 3' away. I can also hear the difference from 1200 miles away
[IF the other station is running barefoot, no linear]
Later... Jim VE7RF
R L Measures, AG6K, 805.386.3734
r@..., , rlm@..., www.somis.org
