[hpsdr] Case for experimental version of HPSDR

[Steve Ireland]

G'day all 

Well, I do happen to have a digital photograph of the case with the lid off,
viewed from the front - if anyone would like to see, drop me an email and I
will email a copy back.

Spent some of the afternoon with a Dymotape Letrogram machine labeling the
sockets on the back of the case...  The (much) more difficult next step is
to build a suitable buffer amplifier for the recycled Wagner flying doctor
radio 100W amplifer board that will serve as the PA.

;-) 

Vy 73

Steve, VK6VZ

-----Original Message-----
From: w9ddd at localhost.localdomain [mailto:w9ddd at localhost.localdomain] On
Behalf Of John Koster
Sent: Saturday, 4 October 2008 8:37 PM
To: Steve Ireland
Cc: HPSDR Reflector
Subject: Re: [hpsdr] Case for experimental version of HPSDR

Photographs?  Please, you can't tease us like that and give us nothing!  
Scan the back of the envelope?  


On Sat, 4 Oct 2008, Steve Ireland wrote:

> ***** High Performance Software Defined Radio Discussion List *****
> 
> 
G'day

It has been interesting to read some of the comments about potential cases
for the HPSDR.

One of the important things to consider is ultimately whether you wish to
make a stand-alone HPSDR that contains not only Ozy, Mercury and Penelope
boards mounted on the Atlas backplane but also items such as a 100W PA, Alex
filter boards, a 12V fan to cool everything and, potentially, maybe
Gibraltar when it comes along.

I wanted to do all of the latter, with the intention of running the HPSDR
from old-fashioned linear power supplies (one switch-mode power supply in my
Pentium IV pc is quite enough 'switch-modeing' for me - more is not worth
the potential RFI problems).

As a result, I did a back-of-an envelope sketch of an old-fashioned
box/radio chassis 18cm high by 29.5cm wide by 30.5cm deep, with a tray-type
chassis fixed to the front panel on which the Atlas backplane plus Mercury,
Ozy and Penelope could be mounted on top (along with a 50 to 100W PA board
out of an old commercial HF radio) and the Alex Tx LPF/Rx HPF boards could
be mounted underneath.  The various USB/DB9/DB25/BNC sockets protrude
through the back panel, so the back of the unit is a kind patch
panel/external connection panel.

My friend Bob VK6CG turned my dodgy back-of-an-envelope sketch into a clever
and practical design, which Phil VK6APH and myself plan to use in a series
of articles next year on how to practically put together a HPSDR in the
RSGB's RadCom magazine and that will hopefully find its way into a book
about practical SDR in the next year or so.  The only problem is finding
time to actually do this.

This design currently exists in prototype form and there are no drawings
available (and, yes, no time to produce them either  ;-)  ).  However, those
old-timers who are used to building chassis for valve or old fashioned
transistor designs will know what sort of chassis I am talking about - the
kind of thing that can be turned out on a garage work bench with a decent
vice, drill and pop-riveter.

Hopefully this gives some would-be HPSDR case builders food for thought.  

Vy 73

 

Steve, VK6VZ

-- 
73,
John, W9DDD


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