[eagle] Re: AO-51 Multiband Antenna???

Bill Ress bill at hsmicrowave.com
Mon Sep 3 20:56:33 PDT 2007


Hi Chuck,

Thanks for your comments and thanks for the pictures links.

Gould has cleared up the mystery. In his "ECHO" issue it had a block 
diagram which, in addition to the V,U,L and S antennas, it showed a 
"multiband antenna" going to the SQRX receiver. In Gould's later issue, 
called "AO-51", the multiband antenna was crossed out. I did not have 
the most recent version of Gould's work.

Gould says a "multiband antenna" was once planned but later dropped.

I'm looking at a potential CubeSat project where we are considering a 
wideband (28 MHz to 435 MHz) antenna and naturally that reference caught 
my eye, knowing that the SQRX receiver covered 10 to 1300 MHz. It begs 
the question, why have such a wideband receiver if you weren't planning 
on doing something with it, at least at one time?

So does anyone have any idea what the "wideband antenna" might have 
looked like?? Was it a SpaceQuest thing or was it one of our guys idea??

Regards...Bill - N6GHz

Chuck Green wrote:
> Hi Guys,
>
> Let me take my best shot at what I'm reading here... there is 
> confusion.  I think the confusion comes from mixing the term 
> "multi-band" with "variable frequency receive, aka SQRX".  They have 
> nothing to do with each other.
>
> The multi-band antenna is an L/S antenna.  That's it.  It's a 
> beautiful piece of work by Stan.
>
> The SQRX is fed from a splitter that is fed from the VHF antenna.  The 
> majority of the antenna signal goes to a preamp and then is split four 
> ways to feed the four VHF receivers.  The smaller portion of the 
> antenna signal goes to the SQRX.  I believe this antenna was designed 
> by Mark Kanawati, but I'm not sure.
>
> If you want to see a couple of thousand pictures, including many of 
> the internals of the satellite, you can look at my collection at 
> http://bach.as.arizona.edu/gallery/main.php?g2_itemId=3759
>
> I hope this helps,
> Chuck
>
>
>
> Gould Smith wrote:
>> As Drew said Stan designed it, with maybe help from Lou.
>>
>> I was told that it is an L Band antenna with S band stubs.  There is 
>> a ground plane under it with radials for L and S band.
>> I wasn't able to get specifics about gain when I did the book.
>>
>> Gould
>> ----- Original Message ----- From: "Andrew Glasbrenner" 
>> <glasbrenner at mindspring.com>
>> To: "Bill Ress" <bill at hsmicrowave.com>; <eagle at amsat.org>
>> Sent: Monday, September 03, 2007 8:06 PM
>> Subject: [eagle] Re: AO-51 Multiband Antenna???
>>
>>
>>  
>>> Stan Wood designed it. It is a dual band L and S antenna, linearly
>>> polarized. I'm not sure what sort of "in orbit data" you are looking 
>>> for,
>>> but it is in use whenever the L band uplink or S band downlink is in 
>>> use
>>> including later this month.
>>> http://n4hy.smugmug.com/gallery/2107663#108915239 has good pics of the
>>> antenna.
>>>
>>> Something in particular you'd like to try?
>>>
>>> 73, Drew KO4MA
>>>
>>> ----- Original Message ----- From: "Bill Ress" <bill at hsmicrowave.com>
>>> To: <eagle at amsat.org>
>>> Sent: Monday, September 03, 2007 7:54 PM
>>> Subject: [eagle] AO-51 Multiband Antenna???
>>>
>>>
>>>    
>>>> Perhaps one of you can detail the "multiband antenna" used with the 
>>>> SQRX
>>>> receiver aboard AO-51.
>>>>
>>>> A perusal of Gould Smith's "ECHO" makes reference to it but 
>>>> provides no
>>>> details.
>>>>
>>>> Does anyone have any in orbit data for this mode. What's the current
>>>> status for its use?
>>>>
>>>> Regards and thanks...Bill - N6GHz
>>>>
>>>> _______________________________________________
>>>> Via the Eagle mailing list courtesy of AMSAT-NA
>>>> Eagle at amsat.org
>>>> http://amsat.org/mailman/listinfo/eagle
>>>>       
>>> _______________________________________________
>>> Via the Eagle mailing list courtesy of AMSAT-NA
>>> Eagle at amsat.org
>>> http://amsat.org/mailman/listinfo/eagle     
>>
>> _______________________________________________
>> Via the Eagle mailing list courtesy of AMSAT-NA
>> Eagle at amsat.org
>> http://amsat.org/mailman/listinfo/eagle
>>
>>   
>
>



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