We have been finding issues using switching power supplies on commercial
2-way radio base stations and repeaters.
The spurs are spread up and down the band at the intervals of the
switching frequency. This causes lots of interference. Although the
spurs are low, (40-50dB down), they are still a problem when you are
trying to receive close to an affected transmitter.
After replacing the switching supply with a linear regulation supply
(Astron) the problems go away.
I wonder how many problems that switching power supplies are causing on
the HF bands?
73
Jim W7RY
-----Original Message-----
From: amps-bounces@contesting.com [mailto:amps-bounces@contesting.com]
On Behalf Of Steve Thompson
Sent: Thursday, July 13, 2006 7:38 AM
To: amps@contesting.com
Subject: [Amps] High frequency heater supplies
Does anyone know if there are problems using high frequency (say 30kHz)
ac to run the heater in a valve with a cathode? For that matter, the
filament in a valve without a cathode?
Thanks,
Steve
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