Another “This isn’t mine” post – but worth sharing my experience with others….
As I was preparing for a trip, i decided i was going to take along a mobile DMR radio, just for grins. One thing I didn’t want to mess with, however, was the GPS puck and more cables than necessary. I had two options. One, find an APX style antenna that would cover GPS and UHF/VHF (and likely a diplexer, or multiple cables to go with it), or two, well, nothing. Or so i thought. In skimming the web, I found the following two links:
So I wanted to follow Pawel’s lead here. I couldn’t, however, find an antenna that would get into my hands in time for the trip (I only had 2 weeks… slow boat from China wasn’t going to work here). I hit up Amazon, and found this guy:
This antenna was a different shape than the one used in other mods… it wasn’t a square patch, but a long rectangle. Here’s an amazon link as of when i put this post up: AMAZON.COM GPS ANTENNA
One note… when removing the front panel – be VERY careful! I didn’t realize the service loop was so short on the jumper that connects the front panel to the SMA on the back end of the radio. I kindof pulled the coax right out of the connector plug when the front panel popped off. oops. luckily, i’m not planning on using that again.
So, I put this thing in, with the metal part shown against the board, and the ceramic element against the top plastic of the 578. Re-assembled, and took the radio upstairs to try it out. Nothing. Bummer….
The next morning, i took the radio apart, and realized that the Antenna’s push-on IPX connector didn’t make a good mate with the radio’s IPX jack. I re-positioned the antenna at the same time – i wedged it in the same spot, but with the metal part exposed when you look at the back of the heaqd, and the antenna element facing the operator controls portion of the control head (essentially facing the back of the GPS icon on the front panel). As a test, in my basement, i powered the radio on and set it on my desk to see if i could get an incidental GPS fix… no dice. For comparison, i powered on my 878 next to it, and got the same results. To get a true test, i powered it up on my dining room table by the back patio door, and went and made a cup of coffee. By the time my coffee was done, the radio’s GPS icon had turned red, and i had a position fix!
I will say, it’d be really nice if the radio had a RSSI panel, showing the quality or status of acquisition… but for now, this is good enough.