toggle quoted messageShow quoted text
is it "safe" to connect an input such as a 1PPS signal to an
input of an AT chip without the AT chip being powered. I know some
chips are fussy about having an input voltage higher than the
I used AND gates with the 1PPS signal on one input and the supply
to the ProgRock or VFO on the other input so the 1PPS is blocked
until the ProgRock / VFO is powered up.
On 24/07/2020 19:25, Hans Summers
Hi just connect all my QRP Labs kits in parallel to
the QLG1 outputs. No drivers. No splitters. Just everything in
olden days we could just use a 74HC buffer chip to act as
a multi-device driver.
On Fri, Jul 24, 2020 at
11:23 AM Dave <VE3GSO@...
Sounds to me like we need a GPS ancillary
driver which would take a single GPS receiver and make
available several, suggest four, identical outputs to
drive a QRPLabs clock, U3S, QCX+, and VFO. OK, maybe
six outputs just in case!
Probably would not be a huge seller, but one would
find a home in this shack.
do you not suffer interference from the
clock/gps combination placed like that?
Unfortunately, I get severe ‘pulsing’ broadband
interference from the gps data bursts from mine.
I started with a plastic case and have spent
considerable time and effort screening, series
choke and resistor filtering, ferrite blocking
and miles of copper tape, short screened leads
and earthing in an attempt to reduce this. I can
still hear it on nearby rigs from LF to 2m. The
only real ‘cure’ is to place it on the opposite
side of my room away from all my rigs.
I have three gps modules feeding U3S kits and
they all have similar issues, but providing I
only want to transmit say WSPR, and not receive
much, it works.
73 Ken G4APB