Hans said:
>Martin also published an article on his high
>level front end in Ham Radio and CQ-DL.
There was an article by Ulrich Rohde in Ham radio about time, in which there was
front end described using an XF9B. I wrote to Ulrich, pointing out that there
was a problem with the filter: he wrote back to say that he'd copied Peter
Martin's article. Peter himself wrote to me to say that he hadn't done testing
as close in as 20kHz.
All this was back in 1974-75: I was working on a high performance rx design for
the military at that company. Left before it was finished and went to work for
Racal for a lot more money!
Despite neve having had a problem with ferrites in that respect, I still prefer
dust iron. I'm using dust iron for toroids in my antenna tuner on 7Mhz with no
problems: they are big - about 1 sq inch cross sectional area and 4 inch
diameter, though.
73
Peter G3RZP
--
FAQ on WWW: http://www.contesting.com/FAQ/amps
Submissions: amps@contesting.com
Administrative requests: amps-REQUEST@contesting.com
Problems: owner-amps@contesting.com
|