[UK-CONTEST] Recent changes to HF CW Field Day rules

[QUENTIN COLLIER]

It's courteous, well thought through and balanced inputs like the one from G3YMC (below) that make subscription to this reflector such a pleasure, and membership of the Contest Committe so rewarding.
 
Let's look at the facts:
 
1. Dave is right to say that the rigs will have a mixture of keying lines. These will need to be paralleled up (perhaps via isolating diodes) so that any one of them can key the rig. The paralleled up point will also need to be connected to the interlock circuit (however that is implemented) - or otherwise how could the entrant be sure that both transmitters won't be transmitting at the same time?
 
2. The shorting of the antenna socket on the "other" rig isn't a means of preventing the second transmitter transmitting - it's a simple means of muting both receivers when either rigt is on transmit as now required for the Restricted and Low Power sections.
 
3. For sure PAs don't like being shorted to deck (although the high VSWR power crankback circuit in the rig should provide protection). But that won't happen with the circuit as published......as soon as one rig goes onto transmit, the other one is prevented from transmitting by virtue of the earthy end of its keying lead having been lifted. So the "other" rig will still be on receive when the antenna socket is earthed.
 
Certainly designers will have to look at the delay between key down and the appearance of RFand the operate time of their chosen relays, but that should be well within the capabilities of any competent FD entrant. 
 
 
73,
 
Quin G3WRR

________________________________
From: Dave Sergeant <dave at davesergeant.com>
To: "UK-Contest at contesting.com" <UK-Contest at contesting.com> 
Sent: Tuesday, 17 April 2012, 9:15
Subject: Re: [UK-CONTEST] Recent changes to HF CW Field Day rules

Um, what an idiotic circuit that is. Mute the other rig by shorting its 
output to ground. Open circuit its single keying input line. Most 
contest stations will have rigs that don't like their PA's shorted and 
will have a mixture of PC keying lines, twin paddles, WinKey etc.

73 Dave G3YMC

On 17 Apr 2012 at 9:01, QUENTIN COLLIER wrote:

> It's accessible by clicking the "diagrams" link on the NFD rules & FAQs
> pages, or direct at the following URL....  
> http://www.rsgbcc.org/hf/rules/2012/CW-FD-2012-FAQ-diagrams.shtml   What
> you're looking for is figure 11.  


http://www.davesergeant.com

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