[Moon] Under what angle is a feed in a offset dish ??

Dominique Dehays f6dro at wanadoo.fr
Sun May 7 16:15:16 CEST 2017


oooops , my reply was wrong , U meant offset angle , not illumination angle

73

Dom


Le 07/05/2017 à 14:48, Anders a écrit :
> Hi John,
>
> My 3.8M offset dish is a Prodelin similar to your 2.4M.
> The f/D is 0.6. The 3.8 meter offset reflector has a 22.62-degree 
> elevation offset look angle. Therefore, when the reflector aperture is 
> perpendicular to the ground, the antenna look-angle is 22.62 degrees 
> in elevation.
> Your dish uses the same original off-set feeds (C-band) as my 3.8M 
> dish. See www.LA8LF.com. I have sent you separately a pdf document on 
> how to install the feeds on your 2.4M offset dish.
>
> 73, Anders LA8LF
> **
>
>
> ****
>
> *
> *
>
> **
>
>
> Den 07.05.2017 08.54, skrev John Lambo:
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> Hello Lunatics,
>>
>> I use a 2,4 meter Prodeline  1270 offset dish for EME now for 7 years.
>> The support for the feed is changed to a other support.
>> This beacuse the feed for 23cm is so big that the old support was to 
>> high.
>> You can look on the home page off OK1KIR how this feed is in my dish.
>>
>> http://www.ok1kir.cz/index.php?name=1296 
>> MHz&page=gals&gallery=15&galpart=3&list=1&start=100
>>
>> But now my problem..
>> If i change the feed from 23cm to a other band say 9cm or 6cm i see on
>> sun and moonnoise a offset on my  OE5JFL readout.
>> This can be in elevation 2 degree and in azimute 0,7 degree.
>> I know it is not that much but what i think this must not be possible??
>> The feed i use for all my EME bands is a RA3AQ feed with a round septum.
>> I wonder under what angle must my feed look to the dish ?
>> So if my dish is water level under what angle looks the feed to the 
>> dish??
>> I know that more amateurs use a offset dish on EME and wonder if they 
>> see the same ??
>>  Thank you for reply...
>>
>> 73  John  PA7JB
>>
>>
>>
>> _______________________________________________
>> Moon mailing list
>> Moon at moonbounce.info
>> http://lists.moonbounce.info/listinfo/moon
>>
>
> _______________________________________________
> Moon mailing list
> Moon at moonbounce.info
> http://lists.moonbounce.info/listinfo/moon
>



More information about the Moon mailing list