[1000mp] YF-110C in Sub Rx of FT-1000MP?

Thu, 22 Aug 2002 00:12:08 -0700

Hi Hans,

According to my Mk V manual the YF-110CN is a 250 Hz, 455 kHz filter 
(Available Options p. 6).  I presume, perhaps wrongly, that that is the 
filter you want to put in the Sub Rx.  Then again, maybe filter numbers 
for the MP are different from those for the Mk V.

I do know that the YF-115C 500 Hz Collins filter for the Mk V Sub-Rx 
will fit and function in a 455 kHz slot in the Main Rx of a MkV.  I know 
this because I put mine there by mistake and wondered why the Sub Rx 
didn't seem very narrow on CW.  I also wondered why K6SE's MPFilters 
program showed a 500 Hz filter in the 8.2 Mhz IF and another one in the 
455 kHz IF when I didn't have a filter in the 455 IF.  When I selected 
both filters the passband did narrow, especially the skirts.  (I've got 
to remember to pay attention to things that don't make sense.)  

So, the 500 Hz Collins not only physically fit the Main Rx 455 Hz slot, 
it also worked.  This must mean that the connectors for the Main and Sub 
Rx 455 Hz filters in the Mk V are physically the same and wired the 
same.  From this I would conclude that a 250 Hz 455 kHz xtal filter 
intended for the Main Rx will work in the Sub Rx.  Whether the insertion 
loss is the same or impedance levels are the same, I can't say.  In the 
days (decades ago) when I dealt with filter designers, the source and 
load impedances for a filter had a very significant effect on the filter 
frequency response.  I don't expect that that has changed.

Something you might do is e-mail International Radio Corporation, 
(Inrad) and ask them how well their 250 Hz 455 kHz filter would work in 
the Sub Rx.  Alternatively, the information may be available on their 
web site.  The general consensus seems to be that the Inrad offerings 
are superior to those of Yaesu so, if you don't already have the filter, 
you might consider getting it from them.  

This may not help but I hope it does.

73 de Jim Smith    VE7FO

[email protected] wrote:

>Hello,
>
>Does the YF-110C (500 Hz - 455 kHz) CW filter fits into the Sub Rx of the
>FT-1000MP (Mark V), mechanical and electrical?
>
>73,
>Hans.
>
>
>Ham Radio:
>PA1HR
>
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>www.qsl.net/pa1hr
>
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>[email protected]
>
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