As some of you know, I'm an old broadcaster who's downright anal about
good audio -- especially when I run AM. My shack is, literally, an
audio production studio with a Pegasus stuck on the end. Since I got
the rig a couple of weeks ago, I've been fighting with audio level and
impedance mismatches, ground loops and -- most stubborn of all -- RF
pollution ( my antenna is nearby and any decent ground would be far, far
away.
Accordingly, I attached resonant radials to the ground post of my
transceiver, used high quality shieilded cables for all connections,
strung every wire and cable with ferrite beads and RF "isolators",
tweaked audio processor preamp, EQ, limiter and compressor levels ad
nauseum, and bridged my processor output and transceiver auxiliary (line
level) input with a messy chain of inline devices such as an impedance
matching transformer, isolation transformer and appropriate adapters.
This all worked after a fashion but the audio still wasn't as clinically
clean and bright as I wanted it -- until today.
I invested about $80 and purchased one of Julius Jones' wonderful iBox
variable attenuator and interface boxes. W2IHY simply did what I did,
except much better. His little box replaces all of my devices and adds
a handy PTT jack and a variable control at its output. Plus, two pairs
of well placed 470 uh RF chokes inside the box zap all the remaining RF
pollution I ha ve. My audio was okay before. Now, after a one minute
installation of the W2IHY iBox, it's exactly what I was after. In fact,
my first contact after putting the iBox in line was an audio engineer in
North Carolina who told me my SSB audio (50 Hz on the bottom and a
bandwidth of 3.3 KHz) was "perfect".
I'm a happy guy and glad to endorse W2IHY's great product. Now --
let's see what she'll do on AM!
73,
Craig
W3CRR
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