Home |
Search |
Today's Posts |
|
#1
|
|||
|
|||
Thanks, Doc.
I don't have an antenna analyzer, so I can't check the resonant freq that way. I was relying on an SWR meter (my shack one). Nothing at all changes when I adjust the antenna. SWR doesn't move. I may try to borrow an analyzer from someone to check that out. The mount and cable are fine. Just got a new 2m/70cm dual band antenna to use until I can get the UHV-4 working. It has a nice SWR of around 1.3 on 2m. On the UHV-4 antenna, I can't get below an SWR on 2m of around 5 or 6, even though it's supposed to be ground independant (1/2 wavelength). I can't adjust the 2m/70cm at all anyway. It's fixed. So as you said, there may be something else wrong with the antenna itself. I may just ship it back to Comet to see what they can find out. That high an SWR is just wrong on 2m. But I may try the counterpoise initially, just to find out. 73, Patrick N3EO 'Doc wrote in message ... Patrick, Sorry, tuning the antenna 'off of' the car won't work (miracles do happen, but don't count on it). The most likely problem is as you thought, a not so good 'ground', but maybe not. Does anything you do change the tuning of the antenna at all? Maybe not get it to where you want it (freq.), but does change it's resonant freq? If not, then there's something else 'going on' besides the inadequate grounding/counterpoise. Make sure you have a good connection through the mount, no shorts/opens except as they should be, etc. And you probably should do something about the grounding/counterpoise, maybe clip a wire to the base of the mount as a counterpoise to see what difference it makes (just lay it on the surface of the car for now). The length of the counterpoise isn't that critical, but too long is 'better' than too short. Changing the location of the mount is also something you might try. Good luck... 'Doc |
#2
|
|||
|
|||
"Patrick Gardella" wrote in message om... Thanks, Doc. I don't have an antenna analyzer, so I can't check the resonant freq that way. I was relying on an SWR meter (my shack one). Nothing at all changes when I adjust the antenna. SWR doesn't move. I may try to borrow an analyzer from someone to check that out. The mount and cable are fine. Just got a new 2m/70cm dual band antenna to use until I can get the UHV-4 working. It has a nice SWR of around 1.3 on 2m. On the UHV-4 antenna, I can't get below an SWR on 2m of around 5 or 6, even though it's supposed to be ground independant (1/2 wavelength). I can't adjust the 2m/70cm at all anyway. It's fixed. Verify that the screw-off connector (NMO or 259) is actually making contact... what you're describing (super high swr on HF, high swr on 2m) points to a piece of unterminated coax with no antenna on the end! Try reading swr without the UHV4 connected... same reading? Bad connection... __ Steve KI5YG .. |
#3
|
|||
|
|||
There is a reason why people post on usenet. They get answers.
And Steve, you have solved a years worth of puzzling and tweaking. The SWR was the same with or without an antenna. The antenna is bad. From the PL259 to the antenna I get no connectivity. I just tested it with a VOM. Why is it that the simple things are the last things you check. Now does anyone know how to take a UHV-4 apart? 73, Patrick N3EO " Stephen Cowell" wrote in message . com... "Patrick Gardella" wrote in message om... Thanks, Doc. I don't have an antenna analyzer, so I can't check the resonant freq that way. I was relying on an SWR meter (my shack one). Nothing at all changes when I adjust the antenna. SWR doesn't move. I may try to borrow an analyzer from someone to check that out. The mount and cable are fine. Just got a new 2m/70cm dual band antenna to use until I can get the UHV-4 working. It has a nice SWR of around 1.3 on 2m. On the UHV-4 antenna, I can't get below an SWR on 2m of around 5 or 6, even though it's supposed to be ground independant (1/2 wavelength). I can't adjust the 2m/70cm at all anyway. It's fixed. Verify that the screw-off connector (NMO or 259) is actually making contact... what you're describing (super high swr on HF, high swr on 2m) points to a piece of unterminated coax with no antenna on the end! Try reading swr without the UHV4 connected... same reading? Bad connection... __ Steve KI5YG . |
#4
|
|||
|
|||
Patrick Gardella wrote:
There is a reason why people post on usenet. They get answers. SNIP Why is it that the simple things are the last things you check. SNIP ... Wrong comment!! The Problem item is ALWAYS the last thing you check!!! I've retired from engineering which included a four year sojourn into professional photography. My medium format camera is/was defective. I check and replaced the battery that runs the shutter. Still defective so off to the repair shop. I received a call from the repair shop yesterday, Friday, describing the defect and requesting approval to repair. ???Are you ready??? The replacement battery was defective!!!! I'm red faced!! I'm also $85 poorer for the want of a $3 lithium battery :-) or :-( Moral[s] to the story: It's always the last thing ... It's always the simplest thing ... It's always the most embarassing thing ... etc. W1MCE |
#5
|
|||
|
|||
Dave Shrader wrote:
Moral[s] to the story: It's always the last thing ... It's a no-brainer, Dave. When one diagnoses the problem, one stops looking. One would be stupid to continue after the "last thing". :-) -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
#7
|
|||
|
|||
"Richard Clark" wrote in message ... On 27 Mar 2004 14:23:33 -0800, (Patrick Gardella) wrote: Now does anyone know how to take a UHV-4 apart? Hi Patrick, Before you do that (what would you fix?); confirm your reading with a load in its place (terminate the connection). Glad to hear my psychic powers are still up to snuff... But make sure that the connection is working before you take the antenna apart... you may be able to bend a spring (NMO) or tweak some contact leaves (259) and get the thing working right! Sometimes connectors have thread problems that prevent them from bottoming properly when screwed on.... check all these things. Make sure there's no little piece of plastic over the important bits, stuff like that. Check for a broken center conductor... trunk lip mounts have been known to do this to coax, and the bigger antenna may be pulling the connection apart. __ Steve KI5YG .. |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|