Poor GPS Function with CT-136 on VX-8DR

[N3KDJ]

I have my VX-8DR now for couple of weeks or more and I really like it. I originally bought it with the speaker mic and GPS Adapter and installed them in the shop and they worked great on the way home in the car.

Later I bought a CT-136 adapter for when I travel and just want to slip the HT in my briefcase and don't want the speaker mic. I installed that and it seemed OK, but I notice that it takes way longer to lock on to the GPS location with the CT-136 than it does with the speaker mic and the GPS installed in it. This goes beyond the speaker mic may be getting pinned to a shoulder versus the CT-136 worn on the belt.

For example, I flew to Pittsburgh this week and when I got my rental car I laid the VX-8DR on the dash and drove about 6 miles in the wide open. No location....so I kept driving in the wide open holding the HT out the window and above the roof line....nothing. When I got to the hotel I walked around in the parking lot with the VX-8DR...it wasn't until I laid the HT down on the grass in the open and made a few phone calls that it got the location....drag.

So I removed the CT-136, reinstalled it....all the pins are fine, solid connection etc. I checked the APRS settings, all OK. I went for a twenty minute walk, much of it out in the clear, and no location. I even returned to where it locked on prior and hung out there with the radio laid down in the grass. No location....I'll verify the acquisition time with the speaker mic attachment when I return home tomorrow but this is a big disappointment to me.

Any thoughts or suggestions?

Thanks.

Phil

 

[KE5MC]

A couple of things come into play that will take a GPS longer to lock.

From last off location to next on location was a significant distance.

When you did turn it on you were moving.

It is possible that the rental car was of a make that had a windshield that blocks the GPS signal. This item is easily disproven by returning to the car after you have a lock and seeing what happens.

The other two will have an impact for sure.

On your walk it should have preformed better and I can't see why unless some connection problem or issue with the GPS module.

Mike

 

[N3KDJ]

CT-136 and GPS Position Failure

Thanks for your suggestions Mike. I'm back home in Connecticut and thought I'd pick up this issue again. I went out into a pretty open area near my home..pretty big opening to the sky. The GPS attached to the CT-136 attached to the VX-8DR did not pick up the position after 5 full minutes timed by my watch. Now it has worked before, even recently in Pittsburgh, with the CT-136, but it's been spotty and some times doesn't acquire at all like now.

I removed it and reinstalled it to the speaker mic and attached it to the radio. On returning to that same spot, I had a satellite fix in 28 seconds.
So I called Yaesu and described the issue to the technician who said "It sounds like you need more experience with the satellites." <huh?- that is literally verbatim what he said>

I explained this radio is probably my 35th or so device with an embedded or attached GPS that I've owned and operated.....Blackberries, 4 different Garmin handheld receivers, 5 cars that have had GPS receivers...even 500+ hours navigating by satellites in a boat... I asked if it was not likely that the CT-136 was faulty and could I just send it to them for examination under warranty. I was told I'd have to send the VX-8DR and the CT-136 and GPS unit and that they would have it for 10 to may be 15 days.
I replied that his was kind of a bummer since I have only had the radio 3 weeks and the CT-136 less than two...he told me to call the dealer and see if they'll exchange it.

 

[KE5MC]

Phil,

Swapping out the 136 for the speaker/mic seems to nail the issue down to the 136. From the same location if you could do a 'cold start' for both the 136 then the speaker/mic that would be better. The 28 sec. lock could have been misleading because the GPS could have been close to locking with the data it had with the 136 in position. I am assuming it was a quick switch from one to the other. I am not sure how you would do a 'cold start' on the VX8.

In addition I would say the technician needs some more 'sensitivity training'.

I think swapping the 136 with the dealer if possible is a good idea. I can't disagree with the request to send in the 3 items. Kind of a CYA thing for Yaesu.

KE5VYU, Mike

 

[Moleculo]

I have both the speaker mic and the 136 and have not experienced this issue. I've used them both extensively. I think I would go back to the store and ask to exchange the 136 to see if it still behaves the same way. It's got to be something simple in that adapter that is causing a loose connection.

 

[N3KDJ]

CT-136 and GPS Position Failure

Yes, I am fairly certain the CT-136 is faulty in some way. I plan to test again later today to ensure the GPS wasn't right on the edge of getting all the almanac info from the sats when I switched to the CT-136. If it can't locate again I'll take it back to the dealer and ask them to exchange it.

Phil

 

[N3KDJ]

CT-136 and GPS Position Failure

Additional test at lunch time today.

Attach GPS to CT-136 and CT-136 on to VX-8DR
Walk out in same clearing with pretty good view of sky
Power on VX-8DR and hit menu
Wait for fix while holding HT out at arms' length
2.5 minutes no fix
lay radio on grass and walk away
4.5 minutes, ....no position fix

Return inside and remove GPS from CT-136 and install into Speaker Mic and affix to radio
Walk to same spot
Power on, menu, wait for fix
1 Minute 20 secs has position fix from 4 satellites, then 5 sats
Walk a ways with it, have direction, 5 sats

Now I am pretty sure it's an issue with the CT-136. I took great care in installing it to the VX-8DR...all the pins look fine in the connectors and it seats firmly and tightens down...wiggled it back and forth gently as tightening it- good connection.

I've called the dealer and they are fine with exchanging it for me ...am going to US Mail it to them this afternoon and they'll just charge me postage back.

 

[huang]

CT-136 and GPS Position Failure

You know all this time I thought it was me but I am experiencing the same thing. It takes forever to get a fix when the GPS unit is on the CT-136, but no time when on the mic. I will have to see if the dealer will let me swap out the CT-136. Thanks for not being nimb like me

Ric

 

[N3KDJ]

Replacement CT-136 Solved Problem!! Yay

Well I got back from Toronto to find that Lentini Communications had come through with a replacement Yaesu CT-136 mount for the GPS adapter for my VX-8DR. I mounted it, headed outside and had 5 satellites within 20-30 seconds from power up and a good position and heading. I have been using it all weekend and it has performed just as well as the speaker mic mount for the GPS unit.
So that means my previous CT-136 was faulty and that Alex at Lentini saved me sending my radio, GPS and CT-136 all to Yaesu for 15 days. Excellent!

 

[KE5MC]

Phil,

Excellent news!

I really dislike shotgun troubleshooting. Good example of logic trumps shotgun.

Mike

 

[ruudsplint]

CT-136

Install the CT-136 without the metal support. I had the same problem, after removing the support it lock within seconds to 10-11 satellites.

PS I don't think the VX-8D is well crafted. Had a lot of issues with GPS interfering in the audio reception, weak audio, slow GPS lock and rapid charger burn-outs. Will sell it and buy a Icom.

 

[N3KDJ]

Bracket

Thanks for your reply, although you can probably see that this got resolved back in June when the dealer replaced the faulty CT-136.

As for removing the bracket, I just think there would be too much strain and potential for breakage on dropping the VX-8DR w/o the bracket- apparently Yaesu thought that so they engineered it. Mine works just fine now.

Finally, I have been very impressed actually with the build quality of the Yaeso handhelds- not just this one, but I feel this one if the best so far and I have had FT-530, FT-51, VR-500, VX-1, VX-2, FT-50 and other units. I have never had one fail nor a problem with a part or accessory. My 14 year old FT-530 works great still after replacing the batteries.

How your GPS could be interfering with your audio puzzles me, but if you prefer the Icom then go buy an Icom.