[hpsdr] Break-out board for 26 pin Hermes connector?

[Alfred Green]

On 7/5/2013 12:14 PM, Alfred Green wrote:
> ***** High Performance Software Defined Radio Discussion List *****
>
> On 7/5/2013 7:51 AM, John Ackermann wrote:
>>
>> Has anyone laid out a PCB for a break out board that would plug 
>> directly into the 26 pin connector and provide RCA or other 
>> convenient plugs for the most commonly used signals on the connector?
>>
>> I know there's a Winford board that will work with a ribbon cable, 
>> but it strikes me that a small daughterboard that would plug directly 
>> into the connector might be easier to manage.
>>
>> If no one's done this, or is working on it, I might take a crack at it.
>>
> I built just such a beast as an interface board for my 10 Gig 
> transverter. A 30mil pcb fits nicely between the pins on a standard 
> IDC connector.
>
> I will dig up the Eagle files and some pics and put them on my site 
> later.
>


The pictures are just with my cellphone camera, so not very good quality.
I haven't worked out how to put up the raw Eagle files yet.

http://nu8i.net/hermes/hermes_io.html

No schematic, but it should be pretty self-evident. I need 0dBm at 36MHz 
for my transverter, so I opted to use the regular Tx output at +20dBm 
and attenuate it on the i/f board. I need a PTT closed contact on the 
coax to enable the xvtr, hence the 10n cap and 1uH inductor as a bias-T.
There is no DC output from the Hermes connector, so I used the powerpole 
connections to power the t/r relay.
Other i/o connections could have been added, but that would have needed 
a bigger board and I didn't need them for this version.

The board is 30 mil double sided which just fits between the tabs on the 
connector.

73  Alf  NU8I
Phoenix  AZ  DM33xo


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