[Yaesu] VL-1000

Thu, 24 Jan 2002 10:53:24 -0800

Jim,

Please have a look at the Quadra page on my site. There is a lot of
information on the Quadra there.

http://www.qsl.net/ab4oj/quadra/quadra.html

The ARRL review of the Quadra is in QST, January 2002; it is also on the
ARRL members' web page.

http://www.arrl.org/members-only/prodrev/pdf/pr0201.pdf

I have a Quadra which has been in my station for 3 years, and is working
flawlessly. The exciter is an Icom IC-756Pro. I have measured IP3 = -34 dBr
at 1 kW PEP 2-tone, vs. -32 dBr at 1.0 kW PEP 2-tone output, as measured in
the ARRL test report.

When using the Quadra with a non-Yaesu exciter, a carrier of about 80W is
required for auto bandswitching and autotuning. To accomplish this, the
"Band Data 2" keying line of the amplifier is connected to the "send" line
of the exciter. The exciter is then placed in RTTY or FM mode to supply the
carrier. This is described in detail in the "mini-review" on my Quadra page.

The only automated feature which does not carry over is automatic antenna
selection by band.

I am not too troubled by 1.0 vs. 1.5 kW output. 1/4 S-unit (1.5 dB) less RF
output is, in my view, an acceptable price to pay for eternal liberation
from the shackles of vacuum-tube technology. (Must concede, though, that
tube amplifiers still have lower IP3 than solid-state designs.)

The MRF150 is still listed in RF Parts' catalogue.
http://www.rfparts.com/mototran.html

M/A-Com now makes the part. http://www.macom.com/data/datasheet/MRF150.pdf
A Japanese equivalent (SRF150) is also available from Yaesu Parts and other
sources.

Do note, though, that as long as the Quadra is operated within its design
parameters, with properly calibrated ALC, the MRF150's should last the life
of the equipment. They are operated with about 20% headroom, and the
amplifier runs cool at 1.0 kW output in SSB mode. It is absolutely
imperative that the ALC be connected and calibrated to limit output to 1kW.
The ALC is the amplifier's first line of defence; the protection subsystem
operates by pulling down the ALC line to reduce  the driving power.

Best 73,
Adam, VA7OJ/AB4OJ
North Vancouver, BC, Canada
http://www.qsl.net/ab4oj/
Note new e-mail address:
mailto:[email protected]

-----Original Message-----
From: [email protected] [mailto:[email protected]]On
Behalf Of N4ULE Charter
Sent: Wednesday, January 23, 2002 17:35
To: [email protected]
Subject: [Yaesu] VL-1000

I have been looking at the Yaesu VL-1000 Quadra system and would like to
have one. I have been told that the MRF-150s are no longer on the market. Is
this true and if so is there a replacement for them. How does the VL-1000
work with non Yaesu radios? Thanks for any input.

73,  Jim
N4ULE