开云体育

I thought I would post a series of pics showing various CW/AM/no optional filter installations. I was inspired to do for a couple of reasons:

1) I can't seem to find much info on performing filter installs. Perhaps someone can point me to some documentation? I can't seem to find any, unlike the FT-101, which I did find adequate installation instructions.

2) I ran across an example of what not to do. In effect paralleling the SSB and CW filters. I have no idea what this would have sounded like on transmit, but I found it on receive because I noticed that there was no difference between SSB and CW RX audio. Once I corrected it, there is now. I am still working through (fixing) all of the issues for receive on this particular rig (of which there are numerous), before I attempt to TX. I may post more info on that effort in the future. In the mean time, enjoy the pics...

I also had the CW and SSB filters paralleled.? The AM filter was empty.? I fixed this and put a .01 uF capacitor across the empty AM filter position in mine.

That's an even simpler AM 'filter' than my three resistor proposal. Was it usable, or just too wwwiiidddeee?!

Regards,

Mark, G4FPH.

I believe that the original Yaesu approach was to jumper the unoccupied AM filter slot to the SSB filter. Resulting in a 2.7 KHz BW on AM Rx. Bypassing using either a cap or resistors will yield a wide-open BW of something like 20 KHz (the IF roofing filter's BW?). Which may be okay... depending on what you're trying to Rx.

Also note, I think in TX in AM mode, the SSB filter is used even if using a cap or resistors. You might want to check your transmit bandwidth in AM mode just to be safe. There's enough splatter on? the bands as it is....