I have had an impressive rack of radio receivers for years. Antennas? I have a few. Antenna switches? Not so much.
It has been a long, long time since I had an antenna farm with 5 or more antennas that I could randomly select.
And, truth be told, there are limitations to how practical that can be when you are doing live comparisons of receiving situation and conditions.
Radio conditions on HF (or medium wave) are rarely stable enough to deduce what antenna is doing what or how one antenna is behaving over another in real time.
And comparing receiver performance from a single antenna choice -- by switching manually by any means? Forget about it.
So what if... what if there was a way of having multiple receivers being fed by one antenna? This would serve, at least, two major purposes:
A.) See how one receiver is sounding over another during live listening conditions
and
B.) Seek out parallel channels of broadcasters. In 2025, the SW channels are not necessarily bursting with interesting broadcasts. Still, it is handy to have the ability to leave one radio on one channel and use one or more other receivers to scan for parallel or similar broadcasts.
This ability to match up audio feeds from stations, on Shortwave or medium wave can go a very long way to "IDing" an elusive or sought after station.
Enter the distribution amplifier. Tom Seeger, VE3PSZ, of southern Ontario, Canada (and a retired electronics designer) has created a wonderful little One-in/Four out quiet distribution amplifier for frequencies from 20 khz to 90 Mhz!
His circuit board (featuring some SMD's) is around 1.25 X 2.25" so that works out to be a pretty small box!
I am building 4 units for my local radio hobbyists in a variety of box sizes - and being on my first build, I am astounded by how much more fun I am having with the power to drive 4 radios from one antenna... I mean... I am deriving more science from the process of being able to simultaneously monitor 4 receivers from one antenna... of course that is what I meant!
My main rack, by example, has a Drake R8, a Drake R8B, An immaculate showroom quality Japan Radio Corp NRD525 - as well as a Kenwood R2000, A Yaesu FRG-7, a Radio Shack DX150B and a brace of external antenna capable portables on an adjacent storage rack. My amateur radio set-up is a Kenwood TS-480SAT hooked up to a MyAntennas.com 80-10 EFLW at 26' above the ground in a property hugging semi-rectangular formation (which offers great low angle omni-directional capabilities. )
My "Listening only" antenna cluster is usually two Wellbrook (or equivalent) ALA100 small aperture loop antennas fed through a dual input (phantom power capable) Misek-Lankford-Ratzlaff Phasers. Currently that Phaser output heads into the 4-Port D/A and is split up to feed 4 radios of my choice.
As an avid medium-wave listener who likes to "wipe out" co-channel pests and discover what's hiding underneath, the Phaser is a tool that quickly becomes "standard equipment" -- you simply cannot live without one once you have used one for a few hours.
Let me say this about the Seeger 4-port distribution amplifier: Once is "in circuit" on your rack or radio bench, it quickly becomes invaluable -- and you wonder: "How did I ever get anything meaninful done before I had this tool?"
The 4-port distribution amplifier also features phantom power (Bias-T) for outdoor active antennas that require 9-12VDC to energize them. The 4-port distribution amplifier has a low current self-resetting fuse to protect the circuitry from coax cable gone bad and outdoor mishaps that result in short circuits.
Completed 4-Port D/A's are available from retired electronics designer Thomas Seeger, VE3PSZ, via his e-mail --