8cc88a23
XPost: rec.radio.amateur.equipment, uk.radio.amateur
From: et472@ncf.ca
On Mon, 26 Jan 2015, Brian Reay wrote:
> "FranK Turner-Smith G3VKI" wrote:
>> "gareth" wrote in message news:ma
gv9$2ac$1@dont-email.me...
>>> "G3XBM via rec.radio.amateur.moderated Admin" >
>>> wrote in message >
>>> news:047d7b5d612a205e9c050d737a33@google.com...
>>>> Although not impossible, it is quite difficult to demodulate a DSB
>>>> signal >> on a simple direct-conversion receiver. DSB rigs are ideal as
>>>> simple >> transceivers to communicate with SSB rigs.
>>>
>>> The reason being that to resolve DSB, the injected carrier must have a
>>> very close phase relationship with the original carrier, and at a certain
>>> phase relationship (don't remember but probably 90 degrees) there's
>>> no output at all!
>>>
>> Why not just filter out one sideband and resolve it as SSB?
>
> While that would work, part of the idea of using DSB in amateur circles is
> to avoid the expense of filters.
>
> Gareth is correct, if the carrier is not inserted in the correct phase, the
> audio is suppressed. He did, however, miss-remember the angle for total
> suppression, it is 180 degrees. Hardly something to make an issue of.
>
> For those interested in the building of DSB radios, I recommend the
> Soldersmoke podcasts. DSB radios often get a mention. There are a couple
> of videos on YouTube by the host of the podcasts which some may find
> interesting.
>
I thuught we taught him all he knows about DSB in
rec.radio.amateur.homebrew.
I'm not sure, there are two Bill M's around, and I'm not sure which is
which. I know one of them was talking DSB some years back in the homebrew
newsgroup.
Michael
--- SoupGate-Win32 v1.05
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