Topband: Rigs for top band

[Brendan Minish]

On Wed, 2007-08-22 at 16:13 +0200, EA2LU Jorge Daglio wrote:
> Iam curious about any comments of the  Icom IC7800 by
> users of Top band, or who, had the opportunity to test one on this band?
> Thanks

I have a 7800 with the 3Khz roofing filters. It's a very good rig, my
previous ICOM was a 756pro Mk2 which was quite inferior to my K2 on
160m 

A well setup K2 is also very good radio for top band however the 7800 is
a bit better than the k2 when things get really nasty like during
contests

I have a K3 on order and I expect that once I have had a chance to do
decent side by side comparisons (in a few weeks time I Hope!) that the
7800 will be up for sale.


What I don't like about the 7800 

One of my great hopes for the 7800 was that the main and sub RX would be
phase coherent allowing for proper diversity reception, A trick I have
been using on my racal ra-3702 for a number of years for tropical band
broadcast Dxing.
Unfortunately the main and sub RXes always have a small offset, this
makes doing diversity (one ear on TX antenna one on a beverage or other
RX antenna) very fatiguing 
I suspect this is due to decimation errors with the DDS  (the main and
sub RX are offset from each other by 100 Khz )  
The VFO's will not track either 


The 7800 AGC is a text book level limiter and cannot be totally switched
off, I much prefer the elecraft K2's 'not quite perfect' AGC response.
The recovered audio has a good sense of depth and is not hard to listen
to but the K2 scores very well in that department too. 


On the plus side the 7800 ergonomics are good, the filtering excellent
and basic RX performance under pressure is more than good enough for
160m contesting.

the band scope is really useful on the higher HF bands and 6m but is not
terribly useful on 160m 

I am hoping that the K3 is as good or better on the basic RX performance
side of things as the 7800 and I am sure that Elecraft will have the
operator ergonomics from the perspective of the CW operator just
right.   



73
Brendan EI6IZ