Monday, March 25, 2013

Piece, part and scrounge...

This story will likely make several of you Elmers cringe... you've been warned.

My HF radio is an Icom 720a, the old kind that requires a mic with a pre-amp.  For the duration of the time it took me to complete Worked All States, I was using an IC-HM12 microphone - those familiar with that microphone will know that it does not have a pre-amp.  This made for several awkward moments in the house: I would be working a station on the other side of the country and having to talk EXTREMELY LOUDLY INTO THE MICROPHONE JUST SO THE OTHER STATION COULD BARELY HEAR ME.  Things would get awkward when my nine-year-old would wander into my radio shack (my home office) around 9 pm with the ever-present, "Daddy, you're too loud.  I can't sleep." Click.  Off goes the radio for the night.  (Dang, right in the middle of a nice pile-up...)

My dad (N5GC) and I had a great time at the Russellville Hamfest again this year.  We both walked away with some cool new trinkets.  But the one thing that I was very excited to find, was a General Electric desk mic, that someone had installed a homebrew pre-amp in.  Here's the catch: The only plug it has is a quarter inch audio plug.  Here's the other catch: The PTT button was disconnected by the previous owner (why?).

Now, before I go further, I need to explain: I am extremely impatient. Also important to know, I am not the best with a soldering iron.  I just had  to get that mic on the air, but I didn't want to cut the plug off and figure out how to connect it properly.  (I'm sure I don't have the right mic plug for this Icom anyway.)  So, I remembered what the inside of my Rigblaster looked like: well labeled pins with jumpers between the input and output.. BINGO!... and out come the alligator clips.

[There it was.  Did you hear the collective groans and gasps from every old ham everywhere?]

So, let me paint a picture for you: The GE desktop mic has two clips connected to the mic and mic-ground.  Those clips run to the output side of the mic and mic-ground on the Rigblaster.  To run the PTT, I have my original IC-HM12 mic plugged-in to the front of the Rigblaster.  So, yes, all-in-all I'm operating with two microphones.

I know it's crazy: CRAZY AWESOME!  I've been blasting through the recent QRM with my full 200 watts with no problem... and most importantly: no more screaming!

1. Yes, I know this isn't a permanent solution.
2. No, I do not recommend that anyone else try this.

Signed,
The Ham That's Now a Ham
Joshua Carroll, N5JLC
about.me/joshuacarroll
---------------------------------------------------
PS - You may be wondering how I know that my signal improved so well.  Sometime last year I was surfing the web and came across websdr.org.  It is exactly what the name implies: it is several Software Defined Radios that you can control over the web.  They are for receiving only (no transmitting), but that's perfect for those times you're tuning your rig (or have a new pre-amp'd mic jury-rigged through a Rigblaster into a 200 watt HF transceiver) and it would really help if you could just hear yourself!  I like using the W4AX in Atlanta, Georgia because I don't have to wait long for the gray-line to assist with propagation.

73!

No comments:

Post a Comment