Fw: Re: Fw: RE: [HBR] THE BEST receiver

[windy10605 at juno.com]

Yes, but the computer defined radios (not computer controlled) can go so
much further by analyzing the noise and just removing some/most of that,
allowing you to hear signals which, to the human ear, are buried in the
noise level. It's the computer analysis and correction of the signal
content that can't be duplicated with analog hardware. We had some guys
at the last club meeting talking about new HP analyzers ($60K++ ....
I don't think anyone ran out to buy one) With the high speed computer
analysis you can actually see the "signatures" of different brands of
radio equipment and different brands of microphones. Like the rifling on
a slug. Amazing capabilities, not real compact for our use, though and
it's still evolving. The cool thing is that you don't have a dead end
radio ....just load new signal algorithm software and place a lot of
attention on the tuned frontend to the high quality sound card used. 

73 Kees K5BCQ 


--------- Forwarded message ----------
From: Bob AH7I <bob at atl.org>
To: HBR Receiver List <hbr at mailman.qth.net>
Date: Fri, 29 Jul 2005 11:21:05 -0400 (EDT)
Subject: Re: Fw: RE: [HBR] THE BEST receiver
Message-ID: <Pine.LNX.4.58.0507291114480.24785 at arthur.atl.org>
References: <20050729.101025.1708.6.windy10605 at juno.com>


Pullen is good because of linearity.
Low distortion noise.
On 40m you really don't need much gain because of background noise.

Any CW signal copiable on the fanciest commercial RX out there, I can
copy
on my National SW-3. Provided the band isn't too crowded with signals.
These days, unless there is a contest, that's the way it usually is.

Heck, I can copy most stuff on an el-cheap-o NE602 based single IC
RX from ramsey at $9.95 hamfest special price.

RX are kind of like cars or motorbikes. All will do the job of getting
you
around if operating as they should. The rest is all optimization and fine
tuning for specific performance...

73,
-bob


On Fri, 29 Jul 2005 windy10605 at juno.com wrote:

> Yep, that brings up another point ....mixers. I've seen many articles
on
> how much better Pullen mixers are from a noise standpoint. I think this
> is basically because it's made up from 2 triodes which would make it
more
> quiet ....HOWEVER, the gain you see is much less than that of a
> Pentode/Pentagrid and by the time you add another stage to equal the
> gain, the total noise introduced may be back to the same level ??
>
> 73 Kees K5BCQ
>
> --------- Forwarded message ----------
> From: "Ian Wilson" <ianmwilson at earthlink.net>
> To: "'HBR Receiver List'" <hbr at mailman.qth.net>
> Date: Fri, 29 Jul 2005 07:25:51 -0700
> Subject: RE: [HBR] THE BEST receiver
> Message-ID: <001001c59449$738ed0b0$6902a8c0 at trabucoian>
>
> Tubes, like all other physical parts, generate thermal noise.
> Additionally, multigrid tubes like pentagrids generate 'partition'
noise
> (caused by the random division of the electron flow between candidate
> targets).
>
> 73, ian K3IMW
>
> >
> > Tubes generate NO internal noise, as ALL "PN" junctions do, thus
tubes
> ARE
> > quieter in the noise-floor department.
> >
>
>
> ************************************
> Visit the HBR Receiver Web Site with over 100 pictures of receivers and
> construction notes...... via http://www.qsl.net/k5bcq/
> there is also a mirror (faster response)at http://k5bcq.edebris.com/
>
>
> Retrieve reflector archived data via
> http://mailman.qth.net/mailman/listinfo/hbr
> ************************************
> Visit the HBR Receiver Web Site with over 100 pictures of receivers and
> construction notes...... via http://www.qsl.net/k5bcq/
> there is also a mirror (faster response)at http://k5bcq.edebris.com/
>
>
> Retrieve reflector archived data via
http://mailman.qth.net/mailman/listinfo/hbr
>
>
************************************
Visit the HBR Receiver Web Site with over 100 pictures of receivers and 
construction notes...... via http://www.qsl.net/k5bcq/ 
there is also a mirror (faster response)at http://k5bcq.edebris.com/


Retrieve reflector archived data via
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