Jim,
At the multi-multi sites, the wide-space broadband noise is what is most
disturbing. Many radios cause the S-meter on all other transceivers on site
to raise by several S-units, simply by pressing the PTT button. You don't
even have to speak into the mic.
At Field Day with two transmitters on the same band (i.e., CW and SSB
portion of the band), then the close-in noise is relavent.
In a recent RadCom test of the FT-3000, Peter Hart had this to say about
wide band noise in that radio:
Transmit noise appears to be an issue with more and more radios these days.
Although the close-in noise is fairly typical, a lower level would be
desirable. However, the wideband noise plateaus at a rather high level,
likely to be a problem with co-sited multiband operations such as special
events, DXpeditions and multitransmitter contest stations unless extra
filters are used. The noise plateau predominates at greater than 5kHz
spacing from the transmit signal and is independent of transmit power even
with zero RF output. This suggests it is due to amplifier noise, whereas
close-in it is due to noise from the frequency synthesiser.
This is not unique to the FT-3000. One month earlier he reported the same
on the FT-1200, and indeed all of the lower cost transceivers suffer from
this problem, including the TS-590.
Unfortunately QST, CQDL and Funkamateur don't seem to want to report on this
kind of stuff. RadCom seems to be the only magazine that will ding a radio
of one of its advertisers.
Clearly there is work to be done in convincing manufacturers to clean up
their TX act.
73 - Rick, DJ0IP
(Nr. Frankfurt am Main)
-----Original Message-----
From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of Jim Brown
Sent: Sunday, July 27, 2014 8:20 AM
To: tentec@contesting.com
Subject: Re: [TenTec] Rigs at WRTC
On 7/26/2014 11:06 PM, Rick - DJ0IP / NJ0IP wrote:
> There is still one more piece missing, far out Phase Noise and my
> hunch is you would find a larger difference.
The published ARRL data currently goes out 1 MHz from the carrier. I
arbitrarily chose to quit at 10 kHz, but it wouldn't take much to add some
data points, logarithmically spaced.
73, Jim K9YC
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