Not a full write up, just thought I would highlight a component that I've recently fallen in love with... A DPDT electromagnetic relay. In combination with my most favourite "component" the electrical choc block, a toggle switch, and some old wire, I've made a remote 2-way antenna switch for under £5. The relay is a model JQX-62F rated at 80A 250V AC / 28V DC and has a coil voltage of 12V DC which is just perfect for powering from a shack PSU.
There's not many videos I could find about using one of these relays as the heart of a switch, but here's a couple..
1) Easy to Build REMOTE Antenna SWITCH for HAM RADIO! - youtu.be/mRHhVPwWLek?si=nidVVZpBAYW0KyWZ
2) 40 Meter Delta Loop Antenna Array Options - www.youtube.com/live/b8z4sZ8QMLQ?si=01EWHZmNqTh-wxd8
The second video, although described to switch directions of a parasitic array, is the way I wired mine, and have just started to ready another one to add a parasitic element to my 10m delta loop later this year.
If anyone's worried about losses in the switch and the choc block connectors joining coax to it, or impedance bumps messing with SWR, then yes.. there probably is a bit of all that. But it's not enough to worry me, my station is running just fine on 10/11m. If it wasn't I wouldn't waste my time openly declaring my love for a component.
Not posting links to sites to buy from. I've seen them go for as much as £30, but shop around and you'll find a bargain. I bought from a well known Chinese online retail seller for £3.86.
If anyone really needs a remote antenna switch then I hope I've given you ideas how you can say a pound or two or a hundred.
My next one readied...