As most hams do, I’ve been watching a variety of items on the eBay website this evening, including an array of audio filters.
Among those filters was the Datong FL-3, a top-notch audio filter produced in Great Britain in the mid-1980s and imported to the U.S.
In the days before DSP was invented, audio filters were one way to add selectivity to a receiver. And in the 1980s, audio filters were the least expensive way to add selectivity to receivers that lacked crystal filters.
My first real CW rig — a Heathkit SB-102 — was fortunately equipped with a crystal filter, making it one really sweet CW rig. Unfortunately, not all receivers or transceivers were equipped with crystal filters. I read magazine reviews about the Datong FL-2 and FL-3, and recognized that they were worth a look. About 15 years ago, I purchased an FL-2 on eBay.
Before that I purchased a Heathkit HW-16 transceiver with HG-10 VFO, and while the rig worked great, the built-in audio filtering lacked selectivity. This is where the Datong FL-2 came in super handy.
The Datong was so handy I put it to use on other rigs in the shack, including my HW-8 Heathkit QRP rig; a Tempo 2020 HF rig, and a Hallicrafters SR-150 transceiver, which lacked any kind of CW filtering.
I kept an eye out for Datong products on eBay, and over the years I purchased two Datong FL-3s, which are the same FL-2 audio filter with an addition of an automatic notch filter. The notch filter works very well, but isn’t as useful to me as the filter’s capability to help isolate CW signals.
A couple of years ago, I finally picked up a Datong D70 Morse code trainer. There’s one other Datong product I’ve looked for but never found, the FL-1, which was the company’s first audio filter unit.
Datong products were an apparent well-kept secret for years; those of us who owned one or more understood what great little units they are. I still have an FL-3 in use on my HW-16 station.
Judging from the results of a eBay auction that ended recently, it appears that the “word is out” about Datong and its mid-1980s technology.
The winning bid for a Datong FL-3 was a staggering $355 — the highest price I’ve ever seen paid for any Datong filter. While I had fleeting thoughts of putting my Datong’s out there for sale, I’m sure I would sorely miss the filters the next time I ran one of my classic rigs.
Of course, the big price could be an one-off thing … the past winning bids for other Datong FL-3s was $80 to $100 — a reasonable price for sure.
OTHER BIG EBAY BIDS. I watched another eBay auction that ended when a Ultimate right-angle bug was listed for $600. That bug is still for sale; another Ultimate sold recently for $152.50 — a good price.
That’s all for this trip …. more to come later.
73 es CUL … de KY4Z …. SK SK … dit dit ….