Help with antenna on a 680

rushl · EVDO Newbie Joined: 15 Aug 2008 Posts: 4

I recently picked up a KPC 680 through Verizon. Where I work I knew the signal would not be stellar, so I also got their antenna for the 680. However, when I plug the antenna into the port closest to the edge of the card (the primary antenna I understand) my signal drops from a bar or two to nothing - I totally lose the signal.

I took the antenna back to Verizon, and they tried it on a different 680 with the same results. I then returned the antenna and they sent me a new one - and it does the same thing. So either there were two bad antennas, two bad 680 cards, or something else.

Before I go and spend more money on another antenna from elsewhere, has anyone experienced this before? Is it common knowledge that the Magnetic Roof Mount Antenna for Aircards from Verizon don't work?

Thanks for all your help!

rushl

Jim_in_VA · Posted: Sat Aug 16, 2008 10:40 am Post subject:

If you are talking about the mini mag antenna Verizon sells, it requires a groundplane. Either put it on a vehicle or put it on some other metal surface large enough. No groundplane = poor performance
_________________
evdo-tips.com

rushl · EVDO Newbie Joined: 15 Aug 2008 Posts: 4

Hmm, so it won't work unless it's on metal? I really need to use this indoors. How large is "large enough"? I put it on the top of a metal filing cabinet and it didn't pick up any signal - I get 0db.

Thanks for your help!

rushl

Jim_in_VA · Posted: Sun Aug 17, 2008 5:25 am Post subject:

Try this test. Disconnect the Verizon antenna from the adapter cable that plugs into your 680, but leave the adapter (pigtail) cable plugged in. Observe your signal reading. Now remove the adapter cable, observe signal again. If you see no change in levels, then either the adapter cable or the modem are bad. Take the modem back to the store, or outside with a laptop, and see if you get a better signal. If you do, the modem is ok and the cable is bad. If you don't, the modem is bad... exchange it. That antenna is certainly not optimal for indoor use.
_________________
evdo-tips.com

rushl · EVDO Newbie Joined: 15 Aug 2008 Posts: 4

Hmm, original post dissapeared...

I get 0db with or without the antenna attached, as long as the adapter is plugged in. With the adapter removed, my signal returns to normal (which is low). I've had two different antennas, and I've tried a second 680 card, all of which had identical results. So unless I've had two bad antennas and two bad cards, I'm thinking something else is up.

Unless I can find a suitably large metal surface (I'll look around at work) I guess I'm in the market for a new antenna. How large should the surface be? And would the Booster Antenna for the 680 sold here work without a metal plate and indoors well?

Thanks for all your help!

rushl

Jim_in_VA · Posted: Sun Aug 17, 2008 6:03 am Post subject:

I have info on using a mobile antenna indoors on my blog here: http://evdotips.blogspot.com/search/label/Mobile%20antennas%20used%20in%20the%20house. My opinion is the booster antenna that 3gstore sells would be better than what you have ... and they offer support as well as a return policy. Antennas are like real estate. Location, location, location.
_________________
evdo-tips.com

AlwaysConnected · EVDO Newbie Joined: 22 Aug 2008 Posts: 7

my antenna just sits on a circular metal disc about 2 inches round....I do have a amplifier though and it is indoors

AlwaysConnected · EVDO Newbie Joined: 22 Aug 2008 Posts: 7

oh i forgot to add that on the KPC 680 the port in the middle does upstream and downstream while the port near the edge does downstream only.

when both are used the middle one does just upstream based on the info from Kyocera I have received.

Jim_in_VA · Posted: Sat Aug 23, 2008 6:21 am Post subject:

Your ground plane is rather small at 2"x 2". The minimum for dual band or 800 MHz (Verizon) is 14" x 14" ... 1900 MHz is 6" x 6"
_________________
evdo-tips.com

rushl · EVDO Newbie Joined: 15 Aug 2008 Posts: 4

daveray · EVDO Newbie Joined: 25 Aug 2008 Posts: 3