Post by Short Wave Sportfishing
I used to use the KWM-2A all the time - on the sly - on the ham bands
when things were slow in 'Nam. :>)
I was the only ham radio operator on USS Everglades for my tour. Call
was WB4THE at the time. My ham radio was the crew's telephone home with
an old friend of mine, Cliff, K4OKD, back on James Island in Charleston.
He ran phone patches for lots of sailors whos ships were at sea out of
our port. His wall was covered with ships' plaques he collected and
letters of thanks from greatful crews.
The comm officers hated me. My captain, a full 4-striper who made rear
admiral, used to terrify the Ensigns and JGs by going into Radio and
saying, "I want to talk to Charleston.", as we approached the Med or some
Caribbean islands. Of course, they'd have to tell him that wasn't
possible in these conditions, to which my captain would reply, "That's
bullshit! I've been talking to my wife on a phone patch from ET1
Butler's little Heathkit radio back in the cal lab for the last
hour!"....(c; Yep, comm officers hated me. With CRUDESFLOT6, our
admiral and my captain using my phone patch to call the wife, my ham
radio station was quite secure in its position of the pecking order. My
own EMO, a little weasle of a CWO2 Navy stuck us with, was always trying
to sabotage WB4THE/MM2. One time, he made the mistake of telling
CRUDESFLOT6 what a terrible security risk it was. He never pulled that
stunt, again, and was told the station would be still there after his
transfer to the Aleutians to run some remote walkie talkie....(c;
Post by Short Wave Sportfishing
They just don't make them like they used to.
Thank God for that! I'm kinda partial to my FT-990/FT-900/Tentec
modified 650W (OUTPUT) Hercules II 12V linear toys, now. It only draws
120A at full power...(c;
Before I became an internet addict, my 1973 Mercedes 220D, the finest, NO
RF NOISE, diesel mobile on the planet sported a trunk remoted Yaesu FT-
900 next to the big Tentec linear and 2 330AH golf cart monsters in the
trunk. The linear and radio control heads were on a gooseneck stalk
conveniently located right under your hand next to the steering wheel.
Under the dash, fed by an old Win 3.1 laptop was a Kantronics KAM multi-
mode TNC for packet, RTTY, etc., with full crossband, MOBILE, high
powered VHF-HF node. Antenna was a home brewed 15' tall Texas Bugcatcher
with Henry Allen's biggest monster coil 3' off the trailer hitch military
insulator. 4' of stainless rod sat atop the big coil ending in an 8-
spoke, 18" diameter capacitor hat made of stainless welding rods welded
to two stainless flatwashers. Atop the capacitor hat was a cut-down
stainless CB whip up to around 15'. As 20M mobile was my favorite band,
the big coil shorting strap for this band would short out the entire coil
and the top whip was trimmed for 1:1 with no coils at 14.200 Mhz. At the
band edges it was only 1.3:1 and the big linear loved it, dearly.
To match the 12.8ohm base impedance, a large Amidon toroid from the
Wireman's HF balun kit was wound with 10 turns of #10 bare copper wire
over several layers of fiberglass insulation wrapped around the core. At
the ends and and at the outside of each turn, was soldered a banana jack
that was exposed on the outside of the plastic budbox it was all mounted
in to keep it out of the weather. One end of the autotransformer was
hard grounded to the Mercedes' frame directly under the whip with a heavy
strap. The shield of the feedline coax was also soldered to the strap.
The center conductor of the feedline had a big banana plug and was,
normally, plugged into the high end tap of the 10 turn coil (except on
10M where it was plugged into turn 6). A heavy strap to a big lug under
the whip's mount was the "tap" that plugged into turn 3 (20-10M) or 4
(40-80M) on the broadband autotransformer at the feedpoint. I melted a
couple of banana plugs until I found one that didn't mind conducting so
much current at such a low Z point...(c; The coil was always too hot to
touch and had to be isolated so it didn't touch the plastic box or it
would melt through it.
NOONE had more field strength from any mobile, or any more signal at a
remote point, running the same input power. I still have it, stored.
For 160 Meter mobile operation, a second autotransformer was wound with
22 turns tapped at 8 turns to match the base impedance at that band. A
second Henry Allen coil, about 40T of #14? was added atop the big monster
coil to tune it. Using the tap on the big coil, I could tune it all the
way across 1.8-2.0 easily, but its bandwidth was only about 12 Khz to the
2:1 SWR points, nearly like a cavity!
For 10M and 12M operation, the capacitor hat and 4' stainless rod above
the big coil quick disconnected and you put the CB whip on top of the big
coil. This tuned 10M with about 2 T of big coil unshorted and 12M with
2.5T unshorted, still making a big signal in Asia.
This installation had a big problem.....CORONA....especially on 160M and
80M. The ends of the capacitor hat rods were bent into a large hook and
they STILL blazed away, even in sunlight, as did the top of the CB whip.
Adding a big static ball to the CB whip top didn't help reduce the corona
spraying off it much at all. Estimating the length of the visible corona
and the humidity at measurement time, we estimated I was creating around
180 to 250KV at the top with a 650W carrier. "HEY, MISTER! YOUR ANTENNA
IS ON FIRE!!", they'd shout to me driving down the road....(c; The old
Mercedes electrical system is resonant on the upper end of 75M, too. AS
you talked to someone on 75M phone, all the dashlights would glow
brightly following your voice. On 75 and 160M phone, you could also hear
what anyone was saying into the microphone OUTSIDE the car because you
could hear the donald duck SSB IN THE CORONA at the top of the beast!
Great fun at a hamfest. I had custom-made warning signs: DANGER RF
RADIATION HAZARD - EVEN WHEN CAR IS UNOCCUPIED all around the big coil
because we used to leave the 20M packet crossband node running to 2 meter
packet from a 50W 2M FM rig to connect 2M packet hams to 20M packet hams.
This created storms of 2M packet QSOs wherever the car happened to be,
once the word got around. I used to leave the car on "Network 105" on
14.105 Mhz to the local packet VHF node wherever it was. Inside the
hamfest, I'd run a Tiny 2 little packet VHF TNC with a tiny VHF walkie
and a little Radio Shack LCD word processor that doubled as a dumb
terminal. Running 50mw from your flea market table, you could work Japan
on 20M packet....(c; Of course, some stupids got their fingers singed
out in the parking lot ignoring my warning signs, crossing the no-mans-
zone around the back of the car taped off with those lane markers they
use at the banks. They just HAD to burn themselves to prove me wrong!...
(c; You also got burned if you touched the body of the car (becoming
part of my ground plane array) below 20 meters. The car body was quite a
few hundred volts off ground-ground, especially the lower in frequency
you got. If you stuck your arm out the window and someone whistled on
160 meters, you could feel your fingers buzzing....
I still have it all, except the batteries of course. The antenna is
stored in my shed, the linear and FT-900 are in their boxes inside. I
don't even have an external antenna up at home for the last couple of
years. Who needs ham radio? I got Skype and Echolink.
It was a great ride for many years I spent on the road working gov't
contracts for the Navy....
Remember - POWER is our FRIEND!