[1000mp] Yaesu Bandpass Filters

[Joe Subich, K4IK]

Rich, 

> I am trying to identify the Bandpass filters that came with 
> my FT-1000mp.
>
> Yaesu Type XF-8.2M-262-01
> Yaesu Type XF-8.2M-501-03
> 

The part numbers identify the filters as 2600 Hz and 500 Hz 6 dB 
bandwidth, 8.215 MHz center frequency crystal filters (Yaesu's 
"stock" SSB and CW 2nd IF filters).   

> After identifying the filters, I am considering to remove the 
> 2.4 K filter attached to the PC Board. I would replace it with 
> the 2 K filter Yaesu Type XF-114SN. Of course I would first have 
> to remove this filter from it's plug-in board. In the 2.4K 455 
> IF slot I would plug in the Yaesu Type XF-110SN 2K filter.  I 
> believe this would now provide a 2K bandpass when the 2.4K 
> Bandpass options are selected. 

You are correct ... However, I have the Yaesu XF-114SN/XF-110SN 
filter pair in the "narrow" position of my MKV and find them too 
narrow for day to day operation.  

> In the 2K slots I would place plug-in Inrad 1.8K Bandpass 
> filters. I believe this would now provide a 1.8K bandpass 
> when the 2K Bandpass options are selected.

Again, you are correct about the effect ... but I don't know that 
there is enough difference between 2.0 and 1.8 KHz to be worth 
the effort.  

If you think the 2.4 KHz (cacsaded bandwidth for the Yaesu stock 
filters) is too wide, you might look at INRAD's 2100 Hz filters. 
The filter curves show 2175 +/- Hz @ 6 dB bandwidths.  It looks 
like their effective (cascaded) bandwidth will be around 2100 Hz. 

> In the Sub-Receiver slot I would place the 455 IF Yaesu Type 
> XF-115S 2.4K  Filter. I am not sure if this would improve 
> anything.

It doesn't buy you anything over the stock ceramic filter except 
somewhat tighter skirts.  The slot is intended for a CW filter. 

73, 

   ... Joe, K4IK