Internal GPS Mod Tech Support/Q&A

[RRR]

Whew.... My head is spinning.....

 

[RRR]

Since Jon is busy, is there anyone else on here that is proficient enough, and would be willing to properly program and install one in my SDS100 once I get my GPS Jon recommended in? For a fee, of course.

PM if you'd like. May be a couple of weeks before it gets in.

 

[jonwienke]

These are the toroids I'm using on the GPS wiring harness to reduce any possible RFI:
https://www.ebay.com/itm/50pcs-Ferr...-Inductor-Ring-Cables-EMI-Filter/252430788071

The connectors are 1.25mm JST. I use a 2-pin for the indicator LED, and a 3-pin to connect the GPS to the scanner board. Do a search on Amazon or eBay and you'll find numerous listings. They make life easier if you have to get back into the scanner for any reason, like GPS module failure.

 

[fdnyfish]

You can get the new Reyax module on eBay for $15+shipping: https://www.ebay.com/itm/REYAX-RY82...t-12V-Flash-antenna-module-RS232/183150562491

The catch is that you have to change the default settings to output the correct format NMEA sentences (they should start with GP instead of GN). To do that, you need to download U-Center here:
https://www.u-blox.com/en/product/u-center

You'll need a way to connect the module to your computer, some type of RS232-USB adapter configured so that outputs are connected to inputs. You don't need the RTS, CTS, etc.

Once you get U-Center installed and the module connected, open up the Configuration Viewer (Menu \ View \ Configuration View). You'll see a list of categories on the left. You'll need to make the following changes in each listed category:

NMEA
Filter: QZSS, BeiDou should be checked
Main Talker ID: 1 GPS
GSV Talker ID: 1 Use Main Talker ID

ITFM
Broadband Interference: 3
CW Treshold: 15
Antenna type: 1 Passive
Enable should be checked (must do this first)

GNSS
Enable GPS, SBAS, GLONASS, all other enable checks should be off

After changing the settings in each category, click the Send button at the bottom left, then Menu \ Receiver \ Action \ Save Config.

If you want to install an status indicator LED, use one like this: https://www.ebay.com/itm/100pcs-3mm...reen-Clear-Lens-2-Pin-Leds-Light/222873908834
Connect it between the PPS output and ground, with a 2.8K current limiter resistor in series with the indicator LED The spacing between the front panel LEDs is 5.5mm center-to-center.

The most difficult part by far is shown here: https://1drv.ms/u/s!ApJIS-l4xqPtgvgVm6kArQYQF88J_w
The GPS data wire (yellow) connects to the second pin from the left of the USB connector as shown. The shield is soldered to the board in multiple locations, so I don't recommend trying to remove it. You need to solder through the hole, which is roughly 1/4" square. Bending the tab out of the way gives you a bit more room and visibility, but it's still very tight.

You'll want to make a 90-degree bend near the end of a solid wire (like the excess lead of the resistor you'll eventually use for the LED), Apply a small blob of solder to the bent tip, position the wire on the correct connector lead, and apply heat. A good connection will bend the wire before breaking the joint. Verify continuity (should read about 12KΩ to ground), and more importantly, verify that you haven't bridged any adjoining pins with excess solder. Fixing that is a total PITA (ask me how I know).

With the settings above, the module will use both GLONASS and GPS satellites to calculate a position, but you can only choose one timepulse reference. So the module will only indicate a satellite lock with the LED if it sees enough GPS satellites to calculate a position, but will calculate a good position fix from GLONASS satellites even if it can't see any GPS birds.

The template for making the cutout for the GPS module is here: https://1drv.ms/x/s!ApJIS-l4xqPtgup_zxqtNGZ7CCxghg
Zero is the center of the belt clip screw hole. Dimensions are in mm. Measure twice, cut once, etc.

The module outputs 9600 baud, so you'll need to set the scanner accordingly.

You made that sound easy !!

 

[jonwienke]

It's a very simple 73-step process, so easy a caveman could do it.

 

[jonwienke]

FYI, I am officially sold out of rechargeable GPS units. The last units are shipping out today.

 

[RRR]

FYI, I am officially sold out of rechargeable GPS units. The last units are shipping out today.

"Rechargable" GPS units?

If you could, could you possibly do a youtube video to show the whole process involved in doing this conversion?

Set up a paypal donation account, I'll put you some in!

 

[nessnet]

RRR:

It's a whole unit/module that Jon builds.
A small plastic case w/ GPS and batteries.
Connects to radio via a cable

Not technically a "conversion"
More like a build....

 

[KK4JUG]

Or you could call it an accessory. I have one and I believe it works better than the recommended puck. Furthermore, it's less trouble to use.

 

[werinshades]

FYI, I am officially sold out of rechargeable GPS units. The last units are shipping out today.

What will you be doing with all this "free time"?

 

[mule1075]

What will you be doing with all this "free time"?

A bit childish really.

 

[werinshades]

A bit childish really.

What do you mean? Jon is leaving for a new job I thought?

 

[mule1075]

What do you mean? Jon is leaving for a new job I thought?

I thought you were being sarcastic my bad. Search for Jon's thread going offline for a while.

 

[Movieman990]

Offline for a while.....

I thought you were being sarcastic my bad. Search for Jon's thread going offline for a while.

The thread is closed:

https://forums.radioreference.com/uniden-tavern/375433-going-offline-while.html

 

[mule1075]

The thread is closed:

https://forums.radioreference.com/uniden-tavern/375433-going-offline-while.html

Post #42 is still relevant as is the thread even if it is closed.

 

[werinshades]

I thought you were being sarcastic my bad. Search for Jon's thread going offline for a while.

I meant it to be funny...that he was moving away or some other job. I don't know about the posting, apparently more to it. Disregard my attempt to be funny.

 

[RRR]

RRR:

It's a whole unit/module that Jon builds.
A small plastic case w/ GPS and batteries.
Connects to radio via a cable

Not technically a "conversion"
More like a build....

If that's the case, then enough info to build one was definitely not given to build one on our own. .... :-(

 

[KK4JUG]

I believe it's Jon's design and no offense, RRR, but I don't think I'd give up the plans either. It's a compact, efficient, well-designed unit that really works as advertised. I'm sure it's a money-maker for him.

 

[jonwienke]

I believe it's Jon's design and no offense, RRR, but I don't think I'd give up the plans either. It's a compact, efficient, well-designed unit that really works as advertised. I'm sure it's a money-maker for him.

It is, but I don't mind releasing the schematic for personal/non-commercial use.

https://1drv.ms/f/s!ApJIS-l4xqPtgvBlzW0NYoY4W7MvJw

Contains photos of the internals and schematics of the GPS unit, and the 436 and SDS100 cables. If you can read my chicken scratches.

 

[jonwienke]

Just for clarification, the FET switching the GPS power is a P-channel BSS84. The resistor, capacitor, and diode network turn the power on when a ground or negative voltage is detected (like a RS232 data output), but keeps the power on even if the output is sending data.

The FET in the SDS100 cable is a N-channel BSS138. It senses a positive voltage from USB pin 3 (DATA+) and grounds the RS232 input line to turn the GPS on when the USB port is active. The 10MΩ bleeder resistor ensures the GPS shuts off if the cable is unplugged.

The ON/Auto switch turns the GPS on by connecting the GPS data in to the RS232 input. This allows the GPS to power on when connected to a SDS100 with the USB port in power save mode, and also allows GPS module settings to be changed without opening the unit case.