[1000mp] Front end mod

[lhlousek]

Just thought I throw in my opinion on the INRAD the front end mod. I haven't installed the mod because I haven't run
into and situation where I felt it would be of any benefit.

I have a full compliment of INRAD filters and haven't yet run into condx where the internal noise of my MkV was
significant compared to the band noise in trying to copy weak CW sigs. In my limited experience, receiver noise can be a
limitation on VHF or UHF but not usually HF.  Of course,  RX noise, and particularly hiss, can be tiring or annoying.  I
find that enabling EDSP demod on my MkV eliminates the hiss.

Band noise is usually less on the higher bands so, on the MkV,  setting the preamp to TUNED increased front end gain on
12 and 10 meters.  The TUNED setting also reduces front end gain on 40 meters and below. It remains the same as FLAT
in-between.

BTW, MDS as measured is different than MDS determined by ear.  The measurement is done with an instrument that responds
equally to the entire output audio bandwidth of the rig so noise level goes up in direct proportion to the bandwidth.
Your ear can discriminate between frequencies so isn't affected the same way. Even though it hears noise at higher and
lower frequencies it can still pick out the signal even though it may be below the aggregate noise level, something the
meter can't do. I haven't found narrow filters to be of much help when copying weak CW sigs. They certainly help with
nearby QRM and might make the signal easier to listen to but if I can copy it with both 250Hz filters switched in, I can
usually copy it just as well using 1.8 KHZ. But I may better than most at this because I played the flute and piccolo in
bands and orchestras and needed to be able to pick out relatively weak sine waves in a huge amount of noise. HI!

BTW, When comparing published MDS numbers for different rigs you should normalize for the actual bandwidth used for the
measurement. More recent QST reviews include bandwidth measurements.  Earlier reviews only list the manufacturer's
stated bandwidth.

Lou W7dzn