I would like to add:
Do not use right angle adapters unless they are of proven excellent quality.
They can create resonances at 23cm band and higher …
Von: UKMicrowaves@groups.io <UKMicrowaves@groups.io>
Im Auftrag von alwyn.seeds1
Cable and connectors.
I have measured very deep (20dB) suck-outs and corresponding reflection spikes around 2.3GHz on some samples of Ecoflex 15.
I have also measured severe suck-outs, but usually above 3 GHz, on poor quality N-Type connectors.
Definitely check your cable and connectors carefully, before working on the aerial.
Regarding the comment on “Heliax”, I do not agree.
All foamed dielectric solid outer cables that I have seen do not have helical corrugations.
I have measured many samples of these cables up to their rated frequencies and above.
The large LCF-78 types are rated to 6GHz and have no problems at all at 2.3GHz.
The upper frequency limit is normally set by circumferential modes in the cable- the spacing between the corrugations is chosen so that the periodic feedback from these occurs above this frequency.
Alwyn Seeds, Director