Galaxy Issues with external SWR meter

Just recently I installed a Galaxy DX979 in my pickup truck. The radio has been "gently used". Seems to work OK. I installed a new Wilson 2000 antenna to the bedrail, right behind the driver's side of the cab. Ran coax to the radio, tune the antenna to get about 1.7:1 SWR on the radio's meter. I go to radio shack and buy a external meter and a short jumper coax to try and fine tune the antenna a little better. Key up the mic and calibrate the external meter, both it and the radio's meter show SWR over 3. I then tested the jumper coax with my multimeter, no short between conductors and no open circuits in either conductor. Figuring the meter is defective, I returned it to radio shack and then go to the local truck stop and buy a cheapo ASTATIC meter. Sure enough, same thing. Radio meter reading 1.6 to 1.7 when connected to antenna, insert external meter and both the radio meter and the external meter read well over 3. I thought the auto calibrating SWR meter on the radio might be fooling the external meter, but it happens regardless of where the meter's function switch is positioned (SWR, MOD, or PWR). I replaced the coax going to the Wilson with a higher quality coax and was able to further tune the antenna to about a 1.3:1 on the radio's meter, external meter still shows over 3 when inserted in line (as does radio meter). I even tried using the old coax (approx 15' long) as the jumper between radio and meter, still no improvement. Remove the external meter and the radio meter shows good SWR once again. WTH?

Has anyone else run into this before? Is the auto-cal SWR circuit fighting the external meter, even without the meter function switch in SWR mode? I'm happy so far with the radio's performance but it would be nice to get a confirmation on the SWR reading the radio shows, as I've heard they are not really that accurate.

 

So what do the antenna analyzers show? And how much would I expect it to cost to have the antenna tuned with one of them?

 

Thanks JJD. I'll try running a ground jumper to the antenna mount later this weekend. Do you think the problem is at the coax connectors to the external meter losing ground?

 

So I've "bonded" the antenna a little bit better. Ran a short 14 ga. wire from bed front bulkhead to the back of cab, then another one from the cab floor to the frame rail. Radio meter reads about 1.2:1 SWR across all the channels, with the external meter connected both radio meter and external read lower than before, about a 2.5:1 on ch 20. Since they both read EXACTLY the same I'm going to assume the radio's internal meter is pretty accurate and that the extra coax jumper must be shooting the reading sky high. Other drivers tell me it sounds good so I guess I'm going to just leave well enough alone for now . Thanks for the advice!