[1000mp] cost of improved IMD performance

Tue, 16 Apr 2002 15:39:49 -0700

Jeff,

A typical marine HF-SSB radio, FCC type-accepted and fully compliant with
ITU and CEPT requirements, has a transmitter IP3 spec. of -32 dB relative to
PEP at 150W PEP output. This radio is designed for a nominal 13.6V DC
supply, and uses 13.8V PA devices.

Can we as radio amateurs really expect much better than this from the
manufacturers, when we are a much smaller market segment than maritime
users, and our price point is often significantly lower than theirs?

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 Jeffrey Pawlan
Sent: Tuesday, April 16, 2002 12:36
To: [email protected]; [email protected]
Subject: RE: [1000mp] cost of improved IMD performance

Dear Tod,

  I was not proposing nor addressing the cost of producing a "Rev"
change/mod to
the existing product. I am of the opinion that the ARRL should do as others
have
suggested and state to the manufacturers in clear and harsh tones that
FUTURE
radios should be designed from the first application of pencil to paper with
better performance as a requirement. I stated previously that I believe the
ARRL is our voice and lobbying agent and has the responsibility to say that
the
downturn in performance (along with generally higher prices) is not
acceptable
and the product being reviewed will not be recommended.

  The comment regarding the larger output transistors is completely in line
with
my thinking and is a miniscule portion of the $2500 price tag. The
manufacturer
could make slightly less profit per radio sold without increasing the retail
price, but the improved radio would then be deemed "acceptable" by the ARRL
lab
and more units would be purchased as a result. Another engineering
improvement
that was tangentally mentioned was running the finals and perhaps the
drivers at
a higher voltage. The cost of DC-DC converters is extremely low and the
radio
could still operate from a 13v supply or battery.

73,

Jeffrey Pawlan, WA6KBL