Re: Wimo 13cms yagi


Dear all,


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 …


Kind regards





Von: <> Im Auftrag von alwyn.seeds1
Gesendet: Samstag, 16. November 2019 11:23
An: UK Microwaves <>
Betreff: Re: [UKMicrowaves] Wimo 13cms yagi


Dear All,


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 G8DOH





Alwyn Seeds, Director
SynOptika Ltd.,
114 Beaufort Street,
SW3 6BU,

SynOptika Ltd., Registered in England and Wales: No. 04606737
Registered Office: 114 Beaufort Street, London, SW3 6BU, United Kingdom.



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