[Elecraft] Question on Alignment

Thu Jul 10 23:14:00 2003

Hi, Julian!=20

I'm not entirely sure what happened that caused Elecraft to recommend
removing the frequency counter probe when the KPA100 is used beyond =
their
explanation that it is to prevent excessive spurious emissions.=20

There are two considerations in meeting the US Federal Communications
Commission rules beyond the obvious "...All spurious emissions from a
station transmitter must be reduced to the greatest extent =
practicable...."=20

The rules also say, "The mean power of any spurious emission from a =
station
transmitter...transmitting on a frequency below 30 MHz must not exceed =
50 mW
and must be at least 40 dB below the mean power of the fundamental =
emission.
For a transmitter of mean power less than 5 W, the attenuation must be =
at
least 30 dB."

So a QRP rig gets an "easier ride" than QRO rigs... sort of. Since a rig
running 5 watts is already 13 dB below a rig running 100 watts, the
specifications are really about the same.=20

It looks like when they added the KPA100 to the K2, either the KPA
introduced a spur that was not there before at all when the frequency
counter probe is left in place, or a spur that was always there is now
stronger, possibly exceeding the 50 mW limit.=20

If it's always been there, I'd bet they weren't aware of it until the
addition of the KPA100 made it 10 dB stronger.=20

Perhaps Wayne or Eric can provide some more information on the =
background of
the issue.=20

BTW, the above quotes are from the Federal Communications rules for the
Amateur Radio Service: 97.307 "Emission Standards" paragraphs "c" and =
"d".

Ron AC7AC
K2 # 1289

-----Original Message-----
From: [email protected] =
[mailto:[email protected]]
On Behalf Of Julian (G4ILO)
Sent: Thursday, July 10, 2003 12:11 PM
To: Elecraft List
Subject: RE: [Elecraft] Question on Alignment

I believed that to be the case for a long time and then someone wrote =
that=20
it was no longer considered necessary to remove the probe. Is it only=20
necessary to remove it if you have the 100W PA, or should it be removed =
in=20
all versions?

73,
--
Julian, G4ILO. (RSGB, ARRL, G-QRP, K2 #392)
G4ILO's Shack: http://www.qsl.net/g4ilo