Re: SRF-M37V and SRF-M37W-Performance differences?
Hi Gary :)toggle quoted messageShow quoted text
Thank you for your kind thanks for my mod articles. I'm sorry that
some folk may have been misled into thinking the selectivity
enhancement would be much greater.
There was not that much effort expended in development. On obtaining
both the DT-210L and the DT-400W I was extremely disappointed by the
very poor selectivity. My gut reaction was that I had to do something
about it and whilst I was 'at it' I took a few photos reckoning that
it may be of use to someone somewhere!
I'm fully aware of the performance provided by the premium filters you
and others have been using for 9-kHz split DX chasing. I've used them
myself in my AOR AR7030 for many years but not yet in a ULR.
Some thoughts: I know you and Guy Atkins have spent quite some time
developing filter mods for various ULRs. I wonder whether it might be
worth investigating the Collins Low-Cost Series of mechanical filters
that have a superior passband ripple to ceramic filters possibly
enhancing the intelligibility of reception. Expensive, but when only
the best will do. Inrad have a 2kHz 8 pole variant:
or a 2.3kHz 10 pole variant:
In the DT-200VX and DT-400W, if space cannot be found for the filter
within the case maybe one of the AA cells could be disposed of to
create a space for the installation the filter. The remaining AA cell
bay could then be loaded with a 3.6V Lithium AA cell.
Thanks once again for your consideration.
On Thu, 2 Apr 2009 23:24:13 EDT, you wrote: