[TowerTalk] RMC 1000 Remote cable

Ian White G/GM3SEK gm3sek at ifwtech.co.uk
Fri Nov 4 03:17:19 EST 2005

Bob Nielsen wrote:
>>> I used rotary joints for many years when I was working on antenna
>>> ranges, but don't recall ever seeing any coaxial models with which I
>>> would feel comfortable running amateur legal limit power levels.
>> The one I have here, a 2 channel unit, is apparently rated at more
>> than a
>> kW.  I don't know what the limiting component is (is it HV
>> breakdown or
>> thermal dissipation).
>I have mainly used single channel (N or SMA connector) types and recall 
>that the N units would handle >1 kW peak, but only ~100 W or less avg,

Practical experience of moonbouncers and others is that N connectors 
will typically handle 700-800W continuous at 432MHz, or 1.5kW if they're 
absolutely perfect. At lower frequencies, the reliable power handling 
capabilities are much greater.

G3LTF and others have used N connectors as rotary joints at the 700-800W 
level on 432MHz for a very long time. The ring on the plug is slightly 
slackened to allow rotation, and then pinned to the plug body with a 
grub screw.

If doing it all again today, I would definitely use 7/16 DIN. They got 
so many things right with that connector.

73 from Ian G/GM3SEK         'In Practice' columnist for RadCom (RSGB)

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