Paul, Thanks again for the addition info - very helpful. Mine came in this afternoon and unfortunately only three of them are LEA-4Ts, the other two are Leadtek LR9548S SiRF StarIII based modules, one of which has a sticker that reads "short" on it. I could request a partial refund but the seller probably just had no idea.
>From my own continuity testing (I haven't powered them up yet) I have determined the following pinout. With the boards in "vertical" orientation, pin 1 is the leftmost pin. It's also the square pin on the footprint. 1 - NC 2 - Vcc/VDDUSB (3v) 3 - NC or 3v for LNA power if sub-board is present 4 - USB DM 5 - USB DP 6 - PPS 7 - GND 8 - NC My next step is to find my 30AWG wire-wrap wire and tack wires straight to the module, then figure out how to get an antenna connected. I don't think I have any adapters this small. John > On Apr 6, 2022, at 1:09 PM, paul swed <[email protected]> wrote: > > John indeed on the 3V. I have lots of 3.3V regs. Not sure I have a 3. But > like you I am thinking the same only maybe simpler. Simply solder it to a > piece of copper board thats larger so I can mount interface chips drill > holes for screws and such. Also some standoffs for 1pps, ext in/out, rs232 > tx1/rx1. Smaller wires are the way to go on connecting to the pins. At 3V > startup is 65ma settles to 57ma. The input is a bit odd. Like you I spotted > the mcl combiner/splitter. The side port is 4-5 db hotter than the top > port. But both work. So its a bit odd as if it was intended for 2 antennas. > Kind of doesn't really matter as its totally working on the TX1/RX1 port. I > set it to 115200 baud. It comes up 9600. That change is sort of silly. > Thinking about mounting the board on the copper board component side down. > Easy to solder copper support wires then. No screw holes kind of a pain. > While soldering I have a small tip iron and found it really needs to be at > 700 F or so to do good job. > On one of my units and in the ebay pix there is a spot of tape that holds > down I assume a small regulator and TCXO. But it really doesn't seem to do > anything. Four of my units do not have that mod. So have not really figured > it out yet. > Good luck. > Paul > > On Wed, Apr 6, 2022 at 12:51 PM John Miller via time-nuts < > [email protected]> wrote: > >> Hi Paul, >> Thanks for sharing this info! I ordered one of these lots as well, and it >> should arrive today, actually. My intention is to re-mount the modules on >> more sensible breakout boards, maybe a Pi Hat. >> >> The 8 pin chip on the board is an MCL BP2G. RF power combiner/splitter >> https://www.minicircuits.com/pdfs/BP2G+.pdf < >> https://www.minicircuits.com/pdfs/BP2G+.pdf> >> >> If I am reading the datasheet and board layout right, the top connector is >> connected to PORT1, the GPS is PORT2, and the side connector is SUM. I >> would imagine that the GPS would be on SUM if the idea was to feed in >1 RF >> signal, but maybe I am misunderstanding it? >> >> I was surprised by your note that the USB voltage input is 3v, but after >> checking the LEA-4x datasheet, sure enough, 3.6v max. I thought all USB had >> to be 5v? >> >> Finally, it looks like the PCB is ceramic, rather than normal >> epoxy/fiberglass. Hopefully that doesn't make removing the modules any more >> difficult... >> >> John >> >>> On Apr 5, 2022, at 9:14 PM, paul swed <[email protected]> wrote: >>> >>> Hello to the group. >>> Gregory had mentioned a deal on Ebay for 5 X LEA-4T receivers at $25. >>> Seemed like an OK deal to be able to have a few units around for >>> experimenting. >>> They arrived and were easy to get operational. >>> They are a little different. The module actually has 2 antenna inputs. >> Took >>> a bit to figure out what was going on. Both work in the L1 band and the >>> side connector appears more sensitive by 4-5 db. But both work. >>> Its a circa 2006 16 channel receiver and does capture WAAS. >>> Locks in about 30 second from cold start. Ublox u-center 8.18 works fine >>> with the unit. >>> Its setup for USB. But that USB is just 3V logic so be careful. >>> The unit runs on 3V. None of the ttl 3V rs 232 ports connect to anything. >>> But TX1/RX1 actually have control and data at 9600 baud. Pins 3-4 on the >>> actual chip. Attaching some small wires allowed complete control of the >>> module after passing through a logic to usb serial converter. >>> 1 PPS works just fine but have not compared it to anything. >>> So for me at least the $5 wonders will be fine. >>> Regards >>> Paul >>> WB8TSL >>> _______________________________________________ >>> time-nuts mailing list -- [email protected] -- To unsubscribe >> send an email to [email protected] >>> To unsubscribe, go to and follow the instructions there. >> >> _______________________________________________ >> time-nuts mailing list -- [email protected] -- To unsubscribe send >> an email to [email protected] >> To unsubscribe, go to and follow the instructions there. >> > _______________________________________________ > time-nuts mailing list -- [email protected] -- To unsubscribe send an > email to [email protected] > To unsubscribe, go to and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] -- To unsubscribe send an email to [email protected] To unsubscribe, go to and follow the instructions there.
