UM150 + YAGI signal loss - need help

aac02 · EVDO Fledgling Joined: 25 Jun 2008 Posts: 18

Just upgraded to a UM150. Signal strength is -90 and up (2 bars). As soon as I plug in the Yagi antenna, the signal strength drops immediately until I actually lose signal about 30 seconds later. What gives?

I have been using the same antenna with a PC5750 card for almost 2 years with no problem (as a matter of fact, old card will not even work without antenna). My provider is Alltel on a 1XEvdo.

Any suggestions?

Jim_in_VA · Posted: Sat Aug 09, 2008 12:26 pm Post subject:

Probably ought to double-check your cable connections. When you plug the pigtail into the modem it disconnects the internal antenna. If your connectors are bad/loose/not seated/wrong size you will have no signal at all. You did get the proper pigtail for the UM150 did you not?
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aac02 · EVDO Fledgling Joined: 25 Jun 2008 Posts: 18

Yes, all the connections seem to be fine.

I know the person who owns the local Alltel store, and he gave me a Marine style non-directional antenna he wanted me to try out for him. That is currently what I just hooked up and seems to be working, and is through the same cables (although not really any better signal than without an antenna).

aac02 · EVDO Fledgling Joined: 25 Jun 2008 Posts: 18

One other thing....

Could the length of the cable to the Yagi antenna be an issue?

The way I have it routed, I think it is between 50 - 75 feet. As I said before, the old card would only connect with the antenna hooked up.

The UM150 drops signal with the Yagi.

Any other thoughts or suggestions would be greatly apprecited.

Thanks

Jim_in_VA · Posted: Sun Aug 10, 2008 5:30 am Post subject:

If the cable worked fine with the older modem it should work fine now, assuming its decent quality and the antennas frequency is compatible. Try putting your modem in a different USB port and rebooting. If you have a Y-cable try that as well.
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aac02 · EVDO Fledgling Joined: 25 Jun 2008 Posts: 18

Jim,

Thanks for the replies, I appreciate it. Here are my latest results:

I tried the y-cable and it at least seemed to not disconnect as fast. I tried adjusting the antenna best signal I could get was -109.

Tried the non directional antenna again, and best signal I got was a -103.

At this very moment inside my house, the signal strength is -90 with the card plugged in direct.

I was also getting very little to no signal using the antenna with a KR2 router as well. Again, if I plug the card in directly to the router, my signal is better.

Is there possibly a problem with the card? Or is there some settings I need to change? I am at a loss...

Thanks again.

Jim_in_VA · Posted: Sun Aug 10, 2008 10:07 am Post subject:

There is always the possibility of a bad modem. It happens. You should try it in a different location nearer the tower and see what results you get. Also put it in HDR or EVDO only mode via the Connection Manager menu (disconnect first). As an additional test unhook the antenna cable from the pigtail adapter (leaving the pigtail connected to the modem) and check your signal strength. Then remove the pigtail and again check your signal. If you see no difference in or out, then the pigtail is not disconnecting the internal antenna and either the modem or the pigtail is bad.
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aac02 · EVDO Fledgling Joined: 25 Jun 2008 Posts: 18

How do you put it in HDR or EVDO only mode? (Is that where you hit control+d and enter the password, because I see no options to select these). I found another older thread topic where someone said you could not change this setting on a UM150 card. And if there is a way, which do I want to use?

Maybe you can also verify this, but do you need to be connected to the internet to actually test you signal? What I noticed was once I actually connected with the antenna hooked up, that my signal did go down (one time into the 80's), but would climb back to 110+ within 30 seconds.

I also tried just leaving the pigtail attached, and signal would drop right out after a few seconds, so it does seem that I am actually getting some sort of usable signal through it, just not a good one.

Just out of curiosity, I took my laptop on the roof with just the card, and was getting a pretty steady -82 to -90 signal. A little better than in the house. I also tried the adaptor pigtail from my old PC5750 card (it is not an exact fit, but did "work" - same results as the other one).

Is it possible that the internal antenna on this card is going to get better signal than with an external one? Seeing as I have tried both the Yagi setup (which has worked flawlessy for the past 2-years) and a non-directional, both without sucess, I am going to have to assume its the card (wether by design or its defective).

At this point, I will try and get a hold of the Alltel dealer on Monday to see what he says. He has been selling this same card with the same antenna to others in my area.

Thanks for the replies and suggestions.

onedavester · Posted: Sun Aug 10, 2008 5:24 pm Post subject:

I am suspicious that you are hitting a different tower when you use the Yagi thus giving you a bad signal from a tower further away. Also even with low loss RG8 coax, you need an amplifier if your cable is that long.

cjones26 · Posted: Thu Oct 09, 2008 7:48 am Post subject:

I had the same thing happen to me recently.. I have a UM150 through Verizon and I bought the external antenna that you can get through Verizon. It worked for about 2 months with no problems and great signal. Well then it started losing signal as soon as I plugged in the antenna. Don't know why , but it just started doing that. So I lef the antenna off and just figured it was the antenna. I stil had a decent connection and speed without the external antenna. Well my modem started losing speed about a week after that and I tried everything to fix the problem. Still nothing would work. Called Verizon and they sent me a replacement UM150. Thought ok it should work fine now, but still can't use the antenna that I have from the old um150 and the speeds are up and down. Now the whole time that I have messed with this thing it is showing full signal on the modem with a -75dbm reading. I think since Verzion has updated recently that the UM150 modems are not taking the update like they should. Now I don't really know what type of update Verizon did, but the UM150 doesn't work well with new Access Manager 6.9.2 version either. Sorry for this being so long, but I thought this might help.