[UK-CONTEST] 2 Station setup ideas please for CQWW

[Paul Beecham]

Don pretty much sums it up. At  G6PZ I've done exactlly the same and it 
costs both in time and money.
When first starting out however things were very different, no filters or 
screening just two rigs interfering with each other very badly. It was 
possible to operate but very frustrating and ended up with at least one 
front end going west in a contest. ( I learnt how to strip and repair a mk5 
mp front end in 45m )
There are also computer issues to take into account, it's not just the cross 
interference to the radio's but if your logging is'nt up to scratch then 
there's not much point.
Screens used to modulate with rf and computers crash before we rebuilt 
ironing out these issues.
Earthing is also very important, basically earth everything to the stations 
earth terminal, don't have radio's' amps, computers etc "floating" above 
ground. Do not rely on the coax to fullfill this role.
So yes it is possible without all this but not good, and can work out 
expensive with rig repairs. As mentioned in another post coax stubbs are 
easy and relatively inexpensive, this will help and with seperation thing 
will be much better, but to be truely competitive there is no easy way out 
and complete station filtering, sceening etc is required.

73
Paul
G6PZ

 ----- Original Message ----- 
From: "Don Beattie" <g3ozf at btinternet.com>
To: <jim at j1mbo.f9.co.uk>; "Uk-Contest at Contesting.Com" 
<uk-contest at contesting.com>
Sent: Friday, September 08, 2006 7:09 AM
Subject: Re: [UK-CONTEST] 2 Station setup ideas please for CQWW


> Jim,
>
> As you know, there are really four ways of fixing the inter-station 
> problem:
>
> a) Bandpass filters on each rx (switchable, or need to change with each 
> band
> change)
> b) Co-ax stubs (need changing for each band change)
> c) LOTS of spacing between antennas
> d) Magnificent dynamic range/blocking performance in the receivers 
> (although
> this does not cure all elements of inter-station problems) In reality no
> amateur equipment comes very near the range required here.
>
> There are two reasons to use these:
>
> a) Inter-station breakthrough
> b) Blowing the front-end of the one or both receivers with excess RF 
> voltage
> down then feeder
>
> At 100m spacing (provided that really is true for all parts of all 
> antennas)
> I think personally you will be safe on (b). But (a) remains a problem. I
> suspect you will still get overload and "whiskers" from the other 
> station -
> particularly so if you are trying to receive on a harmonically related
> band - e.g. listen on 14 whilst working on 7Mhz.
>
> You can reduce the effects by cross-polarising your antennas - vertical
> polarisation for one and horizontal for the other - although this really
> only works for the HF bands. You can also gain a few extra dBs of 
> protection
> by considering the relative positions of your antennas so that the HF 
> beams'
> most commonly used directions put a partial null towards the other 
> stations
> antennas.
>
> At 100m (which is about the spacing I have here between the two towers) I
> don't think you will get away without some problems. In the end, you need
> filters of some sort - co-ax or Dunestar/ICE etc. I use a pair of switched
> 200W Dunestars here, and that kills the problem except for second 
> harmonic.
> If I were really worried about that, I would add the odd stub to take it
> out, but it's not a big issue. If I disable the Dunestars, I get phase
> noise, and also some overload (but I don't seem to fizz the front end)
>
> It may be that others will have additional comments (or even disagree with
> mine !) but I'm sending them for what they're worth.
>
> I guess in the end you try it out, and if you judge that it's all to hard,
> you do a single station entry
>
> Good luck !
>
> 73
>
> Don, G3BJ
>
>
>
>
> ---- Original Message ----- 
> From: "Jim Balls" <jim at j1mbo.f9.co.uk>
> To: "Uk-Contest at Contesting.Com" <uk-contest at contesting.com>
> Sent: Thursday, September 07, 2006 7:52 PM
> Subject: [UK-CONTEST] 2 Station setup ideas please for CQWW
>
>
>> Hi all,
>>
>> We are thinking about running a 2 station setup for CQWW SSB.
>>
>> We currently have no experience of this and was looking for pointer on a
>> cheap and easy filtering option (I their is such a thing!).
>>
>> We are looking to run lets say 20m - 10m on one setup (HFstation) and
>> 40m - 160m on the other setup (LF Station).
>>
>> Antenna's will have a separation of about 100m, we are going to run a
>> vertical and dipole setup for 40m - 160m on the second station tower and
>> a 10 - 20m beam (Spider) and a 2 element Moxon for 40m on the main tower
>> (I guess the 40m beam will be used on the 10 - 20 m station and not the
>> LF station)
>>
>> Both will run 400w.
>>
>> Radios will be
>>
>> HF station 756PROII -  TL922 In Caravan
>> LF Station with be Either FT990 or TS870 - 811H (with 572B tubes) In
>> Awning
>>
>> We cannot afford luxuries like the Dunestar filter setup at this point.
>>
>> Any ideas guy's, Would we suffer much breakthrough etc, is it even worth
>> attempting?
>>
>> Thanks
>>
>> Jim M0CKE
>> _______________________________________________
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>> UK-Contest at contesting.com
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>>
>
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