[Lowfer] Bug found and AFRICAM 4.3 available

Sat, 14 Feb 2004 19:14:35 -0500

In a last minute quick and dirty scheme yesterday afternoon...I used an
SN75175 to take the differential output of the Z3801A and fed a Darlington
pair that's powered by 12VDC. Two 1.5 volt batteries are in series between
the collector and ring input to pull negative. Not elegant but eveything was
right there on the workbench - didn't even have to get up.

Will work on a better permanent solution.

Jay
----- Original Message -----
From: "John Andrews" <[email protected]>
To: <[email protected]>
Sent: Saturday, February 14, 2004 6:54 PM
Subject: Re: [Lowfer] Bug found and AFRICAM 4.3 available

> > I'm using a PNP transistor to invert the GPS pulses, with the old
> > diode-capacitor trick to maintain the negative voltage reference for the
> > RS-232 ports. In my case, the diode is connected to pin 3, the Tx
output.
>
> I'm using a 26LS32 to take the differential 1PPS output from the HP
Z3801A,
> and feeding the TTL signal to a MAX232A RS-232 converter. That should be
> pretty bulletproof (once you phase that differential input correctly).
>
> John A.
>
>
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