[amsat-bb] Re: Dutch transponder versus the Indian transponder.

[Michael Lipp, HB9WDF]

Hi Domenico 

I think we have also another problem: In the last few years, the OP's growing up without fullduplex TRX (Ic-706 and similar) and use the ssb sat. They can't hear her own downlink signal from the bird.

73's de Michael

HB9WDF, Michael Lipp, JN47AE

Am 16.03.2012 um 12:14 schrieb "i8cvs" <domenico.i8cvs at tin.it>:

> Hi Ib, OZ1MY and William, PE1RAH
> 
> Thank you for the information about the diode limiter into the William's
> transponder.
> 
> I got the link of PE1RAH describing the block diagram of indian and Duch
> transponders but without information about AGC or diode limiter.
> 
> http://www.qsl.net/pe1rah/HAMSAT-info.htm
> 
> I hope that William will informe us on this matter.
> 
> 73" de
> 
> i8CVS Domenico
> 
> ----- Original Message -----
> From: "Ib Christoffersen" <oz1my at privat.dk>
> To: <pe0sat at vgnet.nl>
> Cc: <amsat-bb at amsat.org>
> Sent: Friday, March 16, 2012 11:36 AM
> Subject: [amsat-bb] Dutch transponder versus the Indian transponder.
> 
> 
>> Hi all,
>> The two transponders are not built exactly the same way.
>> 
>> The Indian transponder has an AGC - but according to my memory Williams
>> transponder has a diode limiter.
>> 
>> I think that can be the difference.
>> 
>> In theory the AGC will regulate the gain down so that the "stronger"
> station
>> "drowns" the ones with a lower uplink signal.
>> 
>> The diode limiter will of course limit the signal for the strong
> stations -
>> but also create distortion in a broad frequency range for all stations.
>> That is if there is a very strong signal - or many stations at the same
>> time.
>> 
>> Whatever the reason KEEP THE POWER DOWN
>> 
>> 73 OZ1MY/Ib
>> 
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> _______________________________________________
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