[Laser] PIN Diode Suggestion

Tue, 8 Jan 2002 11:13:48 -0800 (PST)

Interesting info on the PDB-V107-nd...wondering if the
PN330cl-nd photo diode works as well in the simular
frontend of k3pgp?

--- Bob Williams <[email protected]> wrote:
> Joel,
> 
> You might try the K3PGP frontend with the Photonic
> Detectors
> PDB-V107-ND.  This PIN has a dark current of 1nA and
> a surface area of
> 17mm.  The full specs are on the photonic detectors
> web site.  Digikey
> sells those for around $2.00 each.  Watch the
> surcharge if you don't
> make the minimum order.
> 
> For reasons that entirely escaped me, I bought the
> C107 - which is
> essentially the same device, optimized for
> photoconductive mode, rather
> than the photovoltaic mode that we are using it in
> (which is what the
> V107 is for)  I was concerned it might not work too
> well for this
> application, since it has a higher dark current. 
> But having come from
> the world of phototransistor frontends, I am
> astounded at how well even
> this does.  
> 
> With all the phototransistor receivers I ever built,
> I had to point at a
> light to test the rx.  With this receiver, the K3PGP
> nighttime front end
> feeding just an LM386,  I have yet to find a
> location in my suburban
> neighborhood where the bare detector (no lenses or
> baffles) does not
> pick up 60 or 120 Hz light noise.  Here in the ham
> shack, the leakage
> into the room from around drawn shades at night is
> enough to detect.  I
> also find that I have to turn off the printer,
> because the AC modulation
> on the green power LED is detectable.
> 
> I built mine dead-bug style on a piece of PC board
> and found that the
> frontend MUST be shielded, as K3PGP states, to avoid
> pickup of RF and 60
> Hz line noise.  I also find that because I left some
> leads a bit long,
> the thing is VERY prone to microphonics.
> 
> I can't recommend this simple, affordable circuit
> highly enough.  Give
> it a try and enjoy.
> 
> 
> Bob Williams, AA1ZC
> [email protected]
> Gales Ferry, CT
> Grid FN31XK
> _______________________________________________
> Laser mailing list
> [email protected]
> http://mailman.qth.net/mailman/listinfo/laser

__________________________________________________
Do You Yahoo!?
Send FREE video emails in Yahoo! Mail!
http://promo.yahoo.com/videomail/