Time for a...

[Andy]

...discone. Possibly. After about 40 years of having our house festooned with VHF/UHF antennas (in addition to my Wellbrook loop and vertical wire at the end of the house), it's time to clean up. I have dipoles, small beams and down-converters etc on a wall-mounted mast just outside the shack window that just peeps over the ridge. I want to tidy this mast up and end up (if possible) with one antenna that will not only allow me to continue listening on the VHF and UHF comms bands, but also to the 250 MHz satellite pirates too. The only antenna that let me listen to these satellites in the past was a dipole cut for the frequency.
Soooo - I've never been impressed with discones as they seem a bit wishy-washy, a sort of 'jack of all trades, master of none' type of thing. Does anyone here use a discone that seems to work pretty well from say 140 MHz to 800 MHz with no major 'holes'?

The general idea is to end up with the Wellbrook and the vertical wire still in place, and the mast also still in place but carrying a lot less clobber - just the 6 GHz downconverter and its own small antenna(for watching drones) and the discone. This should be a lot tidier and there will be fewer coaxes coming into the shack. It all hinges on the discone putting in a decent performance. Over to you, chaps.

[109 Jim]

i know you would need a rotator but for the coverage you want a log periodic will out perform a discone , 73 jim

[Andy]

Thanks Jim. Yup I know that, but a rotator is out of the question now. I removed mine a couple of years ago in the first attempt to reduce the clutter. A 2m/70cm colinear usually does a decent job, but none of them performs well in the 'bit in between' which contains the US satellites around 250 MHz. It looks that whatever I try I'll end up with 3 coaxes - the one from the downconverter, one from a 250 MHz dipole and 'something' for the VHF/UHF comms bands. A discone *might* do OK on 250 Mhz *and* the comms bands and I'd end up with just two coaxes, and I was just wondering if anyone had a good word to say about any particular type/make of discone. I know their wideband, omni-directional nature denies them any gain, but it's worth a try, I think.

[grafter]

One of these, maybe with another diplexer to combine HF and 2M into the lower port and mounted on the mast head would reduce the amount of feeds entering the shack.

https://www.dxengineering.com/parts/cma-cfx-324j

[Andy]

Thanks Grafter. My HF system is not the problem, it's the VHF/UHF coverage that is difficult. Also I want to avoid losses in things like combiners/splitters. I reckon I'm asking for miracles but I'd still like to try a discone even if only to prove to myself that they are not the answer! I might just fiddle about with my old leftovers until something works...

[grafter]

I'm not sure a decent duplexer, triplexer would have a huge amount of loss, maybe fractions of a dB? I'd combine it all on the masthead and use a modern wideband amp with added LPF to negate any feeder loss.

Let us know how the discone stacks up against a resonant dipole.

[dc260]

What about a spiral type antenna for 255mhz in a pvc tube ?

[Andy]

Hi dc. I can receive the satellites, but the object of this exercise is to reduce the number of antennas/coaxes. So I need one antenna that will work on the VHF and UHF 'shopwatch' type bands and also on the 250 MHz satellites. That's why I want to try the (supposedly) jack-of-all-trades discone.
Some sigs I listen to are a bit weak, so I can't afford to lose much signal.
I reckon I'm asking a lot.