[Moon] [Moon-Net] 1.8M DISH/ 2.4M DISH

[DW Harms (Dick)]

Hi Charlie,

Good point 😉
On 3cm I am using a 90 cm Rhode & Schwarz dish with very accurate surface (which is indeed a must on 3cm and up...) so I can forget about moonnoise hi!
I solved that problem by calibrating the dishposition on sunnoise and then move to the moon. It works and I have sofar heard couple of stations like SP6JLW, OZ1HNE and the DL0SHF beacon. 
I am working on a weatherprotected box for my PA and am nearly finished with accurate trackingcontrol. So making QSO's, the next step, is luring somewhere at the horizon 😉

73, Dick PA2DW

-----Oorspronkelijk bericht-----
Van: charlie at sucklingfamily.free-online.co.uk <charlie at sucklingfamily.free-online.co.uk> 
Verzonden: zondag 7 juni 2020 14:46
Aan: DW Harms (Dick <dwharms at kpnmail.nl>
CC: ve1kg at eastlink.ca; moon-net at mailman.pe1itr.com; moon at moonbounce.info
Onderwerp: Re: [Moon-Net] 1.8M DISH/ 2.4M DISH

Hi Dick

Having operated 10GHz EME with dishes from 76cm to 3m diameter, I have found larger dishes easier to point accurately (once you have found the moon).

This may sound counterintuitive,  but the reason is that the larger dishes have higher moon noise and so its easier to find the peak.

Of course if you use auto-tracking, that does indeed need to be more accurate with a larger dish, although small errors in pointing smaller dishes can also be bad, since you have less S/N in the first place.

But given the choice between a smaller dish and a larger one, for me the choice is obvious.

The advice that at 1.8m is better than 2.4m is strange.

73

Charlie G3WDG

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>     	Hi dear Serge,
> Well, in terms of gain there is a of course signifikant reason to 
> prefer 2.4m. I would say the only disadvanrage of a bigger dish is to 
> control the tracking, as the opening angle of the 2.4 is only around 
> 0,8 degrees on 10 GHz.
> Best 73, Dick PA2DW
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>     	Groet, Dick
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> On Sat, Jun 6, 2020 at 7:12 PM +0200, "ve1kg--- via Moon-net"
> <moon-net at mailman.pe1itr.com> wrote:
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> Some what recently said that a 1.8M dish was the best for 10GHz & 
> 24Ghz. I wonder if a 2.4 M dish would not be better??
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> Can someone explain to me the reason why  the smaller dish is better 
> for 10ghz?
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> Serge VE1KG
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> DXCC: 144MHZ
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