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THE AM BULLETIN BOARD => Technical Forum => Topic started by: scottdarling1221 on April 30, 2011, 11:45:11 PM



Title: True am audio for collins 8010a exciter
Post by: scottdarling1221 on April 30, 2011, 11:45:11 PM
k


Title: Re: True am audio for collins 8010a exciter
Post by: w3jn on May 01, 2011, 02:17:17 AM
AME is carrier + 1 sideband.  With a 6KHz filter it's doubtful that it's AME, although I don't know this for sure.  It depends largely where they insert the carrier in relation to the center frequency of the filter.  Despite what you may read Am developed with a balanced modulator is TRUE AM.  If one sideband is filtered out, it's AME.  If both sidebands are present it's just plain ol' AM.

Most likely the exciter has audio bandpass filtering so modulation products way outside the passband of the mechanical (or crystal) filter don't cause spurious products.

At the risk of transmitting all kinds of spurs and wideband junk, you could feed the audio directly to the balanced modulator and bypass the filter.  That would give you hifi AM at the risk of making you decidedly unpopular on the band, unless care was taken to limit your audio bandwidth before the balanced modulator, and that no spurs (which the 6 KHz filter is meant to eliminate) exit the RF output of the exciter.



Title: Re: True am audio for collins 8010a exciter
Post by: w3jn on May 01, 2011, 12:01:03 PM
Yes, but I'd make certain to look at the thing with a spectrum analyzer before you put it on the air.


Title: Re: True am audio for collins 8010a exciter
Post by: K5UJ on May 02, 2011, 08:54:33 AM
What does AME stand for?


Title: Re: True am audio for collins 8010a exciter
Post by: w3jn on May 02, 2011, 10:16:54 AM
AM equivalent


Title: Re: True am audio for collins 8010a exciter
Post by: SM6OID on May 03, 2011, 04:44:29 PM
And how does it sound?


Title: Re: True am audio for collins 8010a exciter
Post by: K3ZS on May 04, 2011, 10:31:31 AM
CHU, the Canadian time station is an example.  You may receive it on 14.670 MHz in Sweden.


Title: Re: True am audio for collins 8010a exciter
Post by: w3jn on May 04, 2011, 11:05:54 AM
k

Why on earth did you edit and delete your posts?  Now this thread makes no sense whatsoever.


Title: Re: True am audio for collins 8010a exciter
Post by: W3RSW on May 04, 2011, 03:52:16 PM
yeah, why?

-makes one sound rather shy or afraid of looking somewhat uninformed.
Well, we all are, some more than others at times.

so just wade in.
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