Trantec aerial length

[sunray]

I swap mine happily from that band to ch 70, and there's no issue with the length.

My experience is different. That was the reason for OP. I had all CH38 body pack aerials and found their performance on CH70 packs to be really poor.

 

The initial problem and results of subsequent tests showed defininate reduced range and some significant dead spots which aren't anything like as apparent with the proper aerials.

 

[paulears]

remember the old TV bands are HUGE. Channel 38 is a big jump in frequency from 70! 65-70 is much closer. Still a difference in efficiency of course, but happily swappable. 30MHz or so at UHF isn't too bad, but over 200MHz is quite a big difference.

[sunray]

remember the old TV bands are HUGE. Channel 38 is a big jump in frequency from 70! 65-70 is much closer. Still a difference in efficiency of course, but happily swappable. 30MHz or so at UHF isn't too bad, but over 200MHz is quite a big difference.

Absolutely right. My OP was due to the aerials getting mixed up and I only had the longer size. Initially I suspected some localised interference but it only seemed to affect the belt packs.

 

The problems took me right back to the days of EDC VHF...

 

 

I'm sure that proper analysis of the belt pack aerials would prove to be horrendous but of course radio mic kit can't read test kit.

[paulears]

I read all sorts of rubbishy claims on antennas of various designs for handheld 2 way radios, so in a moment of madness, bought as many different versions as I could and tested them, and the results were quite interesting - practically all of them were compromised in some way. If you want to be bored to death, you might find it useful (although I doubt it)

 

https://www.youtube.com/watch?v=LVzlFTIMV5A&t=684s

[sunray]

As a little follow up to this I put in a system before Christmas for a U3A meeting with 8CH of mics, 4xCH70 S4.4 RX with fixed aerials approx 1/4wave & 4xCH38 S4.16 RX with standard detatchable 1/2wave rubber aerials, the 2 stacks of RX's were approx 20m from the performance area and all showed virtually a consistant 4 blobs of signal strength except the CH38 RX with CH69/70 aerials which showed 2 or 3 blobs of signal.

I confess I was a little surprised it made susch a difference at that distance and even swapped aerials with another RX to make sure that was the cause.

Edited January 20, 2020 by sunray