Tuesday, November 11, 2014

What Ever Happened to 2m FM?

My first 2m FM rig was the Icom IC-230, like this one.
I was reading an article in a recent issue of QST, talking about the rise of FM in amateur use, and it dawned on me. It's been nearly 10 years since I had a VHF FM radio in the car.

Thirty-five years ago, in September of 1979, I got my first 2m rig -- an Icom IC-230.

My brother Ben, now NJ8J, had gotten a 2m handheld several months before. While home before college, I noticed how much fun he was having on 2m, and I wanted to be part of it as well.

One of his 2m contacts, a gentlemen whose call I have forgotten, had a Icom IC-230 for sale, and the price was reasonable for my college-bound budget. Ben and I went out to his house and came home with the rig. I fashioned a 1/4-wave whip using 19" of coat-hanger wire with four copper wire radials attached to an SO-239 connector. A quick jaunt out the dormer window and the antenna was attached to the roof just above the window.

That old house was in a prime spot for VHF. Right at the top of a hill, it was the highest spot for a couple of miles around. And it didn't hurt the antenna was near the top of the roof.

Propagation that week of September, just before I headed for school in Georgia, was also fortuitous. There was a massive troposphere opening, and I worked FM repeaters in four or five states in just a couple of days. I don't believe I've ever experienced such an opening since then.

Back in the days before frequency synthesizers, the IC-230 was an ingenious design. It used about 18 different crystals in a mixing arrangement that allowed it to generate all 67 of the 30 kHz spaced channels from 146.01 through 147.99, plus the standard repeater offsets of +/- 600 kHz.

Ingenious as it was, this arrangement was obsolete by the time I purchased it. The 2m band had expanded to allow repeater operation in the 144 and 145 MHz sections of the band, and some repeaters were operating on the 15 kHz splinter frequencies, which the IC-230 couldn't access. The rig did have provisions for adding three extra crystals to generate oddball repeater frequencies, as well as a switch position for an external digital VFO. On my college budget, I never could afford these options.

Even so, I could generally find plenty of activity on the main 30 kHz channels. Somewhere along the line, I bought a car, and of course I put the IC-230 in it. My antenna was a home-brew magnet mount made out of a tuna can with a plastic lid, a phono connector with a 19" curved copper wire sticking out of it. Not sure where I got the magnets, but they were strong enough to hold it in place. While the IC-230 was sold long ago, I still have this home-brew mag-mount.

Driving around downtown Atlanta, I often heard other hams complain about intermod from the other VHF signals and the tall buildings. Not with the IC-230. The designers put five helical resonators in the front end to pass the 146-148 MHz signals. Those resonators were like a brick wall to out-of-band VHF signals. In downtown Atlanta, I might hear some picket-fencing, but never any intermod. That's the one feature of that rig I miss.

I eventually traded in the IC-230. I had a Heathkit HW-2036 for a while. I also bought several hand-held transceivers. Today, I have an Alinco DR-570 as well as an old Yaesu FT-227RA Memorizer. Neither of these rigs has seen the inside of a car in over 10 years.

I don't know what it is - perhaps it is the rise in cell phone, but there doesn't seem to be as much activity on 2m as there was a couple of decades ago. Maybe it's just because hams stopped putting rigs in their cars....

1 comment:

  1. It has gotten nearly impossible to install a rig in a
    modern car. When I traded in my 1997 full size van
    for a Mitsubishi Eclipse in 2001 it was the end of my
    mobile experiences.