[Elecraft] Other Radios

[k6se@juno.com]

Doug, W6JD wrote:

"My OTHER radio is a Kenwood TS-870 which I purchased fairly soon after
it was introduced. The idea of DSP i.f. filters really appealed to me.
And I was initially not disappointed the skirts on the things are
fantastic. But soon the bloom was off the rose...it doesn't matter how
sharp your filter skirts are when just remotely loud signals 50 kHz away
de-sense the receiver..."
----------
That's exactly the problem I meant when I said "...the TS-870S has
problems...".  The front end of that radio is wide open and the ill
efects happen before the signal reaches the DSP stages.  I asked Kenwood
reps several times at conventions when they would come out with a
replacement for the 870 which had xtal filters in the early stages and
870-type circuitry afterwards.  They then came out with the TS-2000,
which is not at all in the same class.  I've given up on Kenwood.

As I said, "My prayers have been answered by the inroduction of the
Ten-Tec Orion".  They're now doing with the Orion what I wanted Kenwood
to do with the 870.  And Ten-Tec has gone a few steps further -- The xtal
filters are front-panel selectable -- They are not only in the early IF
stages, they are BEFORE it, as "roofing" filters -- The later IF stages
are strictly DSP (as in the 870) but not with only one 32-bit processor,
but two!
==========

"...and forget the noise blanker. I live reasonably close to two high
power, reasonably active stations, one of which is run by a bunch of avid
contesters and if either one of these guys is on I have to head for the
WARC bands."
----------
As I previously noted, noise blankers are a bad thing to use if there are
nearby (in frequency) strong signals.  Nowadays noise blankers work on
the noise pulses occurring within the passband of the roofing filter,
which is why they don't work so good when a strong ham signal is also in
the passband of the roofing filter.  It is my hope that, because of the
much narrower "roofing" filter in the Orion (250 Hz if you select that
filter) noise blanker performance will be better than anything available
in the past.
==========
 
" Another problem...when I finished my K2 and started playing with it I
was convinced that it must be broken. There was no noise, even with the
gain cranked up all the way! (Well, a slight hiss) Then I tuned across a
signal, WOW. The '870 noise level is unbelievable, which I attribute to
all the digital stuff."
----------
That's strange, because although the 870 has a wide-open front end,
moonbouncers rate the 870 as "best" among the modern transceivers when
used as the IF stage for their UHF converters.  This is based on the
quietness of the receiver and the excellent 50 Hz selectivity (better S/N
with narrower passband) the radio has.

73, de Earl, K6SE