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Need info: Supply pwr rating for QLG1 GPS RX #qlg1

 

Hi gang,
after buliding the QLG1 kit it is not claer to me what the max. pwr rating for the stand alone QLG1 RX is.
I am now suppling 5V into V+ and GND of the 6 pin header. Everything works fine up to now.

I know there is an LM317LZ build in with the max pwr rating up to 37 volts.
The schematic is pointing this to me. But it is not clearly stated in the manual.

Can some one pls confirm that the kit will also handle 12 volts to pin V+ and GND of the 6 pin header? 

Tnx fer reply ... and the bandwith, just need a confirmation
--

72/3`s de sTef 
-- 

DM5TU / VY1QRP - DL-QRP-AG *GM* - GQRP #8769 - CalQRP #034 - NAP #1607

Fred VK2WS
 

I think you are incorrectly referring to power levels, when the issue is voltage levels.
The board must be supplied with +5V.
+12V is too much. The purpose of the LM317LZ is to regulate the +5V (supplied from somewhere off the board) down to +3.3V since this is what the GPS/RF module requires.
There is no regulator on board to provide +5V from an external source.
There is a sentence in the instructions that kind of explains things - "The additional circuits are supply filtering, voltage regulation (the module requires 3.3V operation), level shifting, and LED indication."
The schematic diagram clearly shows +5V on the left side of the LM317LZ (as an input) and +3.3V on the right side as the regulator output.
If you should apply +12V to the board it is quite likely that the GPS/RF module will be OK, since it is powered by the 3.3V derived from the LM317LZ, but other devices (including the 74ACT08) will be fried. If the LEDs are in an ON state, they will be bright, but maybe not for long.
73 Fred VK2WS

N6WKZ
 

Fred and sTef,

Fred is correct. Be sure to feed the GPS with 5 volts ONLY.

The 74ACT08 is connected directly to the input, and is 5 volts.

How do I know ? I just fried one! That's why I use sockets!

73

Phil N6WKZ

On 10/3/2019 12:57 AM, sTef - DM5TU / VY1QRP wrote:
Hi gang,
after buliding the QLG1 kit it is not claer to me what the max. pwr rating for the stand alone QLG1 RX is.
I am now suppling 5V into V+ and GND of the 6 pin header. Everything works fine up to now.

I know there is an LM317LZ build in with the max pwr rating up to 37 volts.
The schematic is pointing this to me. But it is not clearly stated in the manual.

Can some one pls confirm that the kit will also handle 12 volts to pin V+ and GND of the 6 pin header? 

Tnx fer reply ... and the bandwith, just need a confirmation
--

72/3`s de sTef 
-- 

DM5TU / VY1QRP - DL-QRP-AG *GM* - GQRP #8769 - CalQRP #034 - NAP #1607

Don DeGregori
 

As for current draw of the QLG1, I see a bit more than 35 mA on my bench supply supplying 5 volts.

Don