FYI, my "real" job starts a 12-hour, 7 day schedule on Monday. I am still doing GPS installations, I just won't be able to guarantee my usual week or less turnaround from now until sometime in January. I'm going to finish the work I have this weekend, but any new work will take longer than usual.
Internal GPS Mod Tech Support/Q&A
- Thread starter jonwienke
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Astrogoth13
Member
I have an HP2 for you to experiment on. It's an expensive radio but an internal GPS would be neat and worth the risk. Interested? What would you charge?
Astrogoth13
Member
Sounds like a plan. I'll contact you in a week for the details, if that's okay with you.
DI outputs RS232, AI outputs TTL.
RS232 is preferable, because you don't need the conversion chip, which will use any excuse to let out its magic smoke.
The 636 is only suitable for mobile scanners. The RYN25DI is better for handhelds.
RS232 is preferable, because you don't need the conversion chip, which will use any excuse to let out its magic smoke.
The 636 is only suitable for mobile scanners. The RYN25DI is better for handhelds.
Astrogoth13
Member
And the HP2 is a bit of both. This could be interesting.
Astrogoth13
Member
True, but that would make it a semi-mobile unit. 
Due to higher than expected demand for my services, I’ve temporarily run out of GPS modules. I have more on order, but it will probably be about another week before they arrive. I'm still in business, but your patience is appreciated.
JamesO
Member
I guess this is a good kind of problem to have with the exception of the people waiting on the modifications!
Jon, how did you verify that there are no noises being introduce by the GPS module being so close to the internals of this scanner?
The mod includes a power switch for the GPS.
When there is a background noise you suspect is caused by the GPS, turn it off. If the noise suddenly goes away, and resumes when the GPS is powered back on, it's caused by the GPS.
I also used a SDR on a USB extension cord as a RFI sniffer, comparing GPS on/off RF dB values on a variety of frequencies with the SDR antenna next to the GPS module.
The Reyax module is the only one that passed both tests with no detectable RFI on any frequency I have tested.
When there is a background noise you suspect is caused by the GPS, turn it off. If the noise suddenly goes away, and resumes when the GPS is powered back on, it's caused by the GPS.
I also used a SDR on a USB extension cord as a RFI sniffer, comparing GPS on/off RF dB values on a variety of frequencies with the SDR antenna next to the GPS module.
The Reyax module is the only one that passed both tests with no detectable RFI on any frequency I have tested.
RYN25D1
I've successfully modified my radio and have already gone thru two of these modules. They work for about two to three weeks then just stop working (no GPS fix). The scanner still shows the GPS in the bottom right corner and the settings haven't been changed. But it doesn't get a fix (blinking red), although on power up I see the lights, fixed and steady green and a quick red flash from the other.
Do you have similar issues with your modules? how do you trouble shoot this?
I've successfully modified my radio and have already gone thru two of these modules. They work for about two to three weeks then just stop working (no GPS fix). The scanner still shows the GPS in the bottom right corner and the settings haven't been changed. But it doesn't get a fix (blinking red), although on power up I see the lights, fixed and steady green and a quick red flash from the other.
Do you have similar issues with your modules? how do you trouble shoot this?
I have had one customer report a similar failure, but haven't had the chance to do a post-mortem yet to see what happened. Look back in this thread for a link to the u-blox test and diagnostic utility, that may offer some clues to what happened.
Note that the module is susceptible to damage from static discharge into the patch antenna. That is the most likely cause of sudden failure after several days of operation, given the absence of heat buildup in the modules.
Note that the module is susceptible to damage from static discharge into the patch antenna. That is the most likely cause of sudden failure after several days of operation, given the absence of heat buildup in the modules.
I give the patch antenna several coats of truck bedliner, which closely matches the scanner case visually, offers some physical protection against bumps and scratches, and forms an insulating layer to protect against static discharges.
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