The holy grail of antennas

[Steve G4WCS]

Originally Posted by Radio Wrangler

Disco door hinges don't make a particularly good RF connection. I added a pair of generous cross-section braids and found them a benefit.

Plan C was to take out the back sunroof glass, replace the glass with an ali plate supporting a Clarke Pneumatic mast... never happened!

David

Thats a good point, thanks. I suppose another benefit to your plan c would have been one less thing to leak in

[majoconz]

Clark Masts. There's a blast from the past - way back in the late 60's I worked for the CAA at the engineering workshops near Gatwick. We had a couple of Series 2 LWB Landrovers with 70ft masts with a load of equipment in the back. They were used to investigate radiation patterns of the glideslope transmitter antennas and some remote monitoring. We nearly lost one when a newbie forgot to extend the support legs.

[Steve G4WCS]

Bit of sporadic E. the last station on the video has an interesting echo. Unsure whether multipath or some fancy echo mike

https://youtu.be/VDVlw6LPqPA

[Restoration73]

I bought a couple of these as I had a twin 5/16" dipole mount ;

https://www.radioworld.co.uk/radiowo...-cb-radio-fire

The dipole antenna without adjustment is resonant at 25.9MHz (close enough for 24MHz)
and I use it horizontal - will tune to 28 MHz with ATU.

[g4wim_tim]

Originally Posted by Radio Wrangler

I thought the holy grail of antennae was the CFA (Crossed-field Antenna, though I'm guilty of usually saying Closed Field Antenna)

If you look into it, fasten your seat belt and prepare for a bumpy ride.... taking in Aberdeen, Egypt and more recently the IoM.

David

Sort of related to the CFA, VMSK very minimum shift keying - another 'invention' which attempts to rewrite the rules of communication theory.

Phil Karne an ex co-worker did quite a 'number' on it - worth a read, here's a snippet

Introduction
Mr. Walker has invented a family of modulation schemes he calls Very Minimum Shift Keying, or VMSK. He claims VMSK achieves spectral efficiencies of 90 bits/sec/Hz or more while requiring no more power than conventional modulation methods such as BPSK.
These claims are in direct violation of the mathematical principles of digital communications discovered by Harry Nyquist (1928), Claude Shannon (1948), and others. These fundamental principles are as firmly established as the laws of thermodynamics; neither is at all controversial among competent engineers. Unfortunately, thermodynamics and communications theory are arcane (and related) subjects that many laymen either misunderstand or refuse to accept. Hence we still have cranks trying to build perpetual motion machines. And we have Mr. Walker and his VMSK.

My interest in debunking VMSK is very simple: people are investing real money in a technology that can't possibly meet its inventor's claims. And since the subject falls into my personal field of expertise, I feel a civic duty to speak out.

http://www.ka9q.net/vmsk/

Mods, feel free to delete if too far off topic.

[Radio Wrangler]

Yes, we're at risk of the thread turning into a collection of daft theories. We'd better steer back to antennae.

(As for VMSK... look up 'Stenode Reception' and you'll find it wasn't new. But that would be a whole new thread.)

David