SWR on 2m?

[CVD]

I’ve just installed a Kenwood 281a, with a Larsen 2/70 HW antenna. I don’t have a VHF SWR meter; so I tested it with a CB SWR meter (reversing the XMTR/Ant lines ). Per this link, that is supposed to give me a ball park 2M SWR reading. http://www.kb6nu.com/no-vhf-swr-meter-no-problem/

I’m getting the following readings:
144.000 - 1.4
145.000 - 1.7
146.000 – 3.0
146.560 – 3.0
147.000 – 4.0

Any suggestions on the cause of the high readings at 146.000 and above?

Anyone in Corona/Ontario/Riverside area have a real VHF SWR meter I can borrow? I'll bring it to you for a quick check.

Admission – my soldering is ugly. I tested the 259 connecter; fairly sure there is no short, but I wasn’t successful filling each of those 4 holes nicely.

Thanks,
Cliff

[Roger]

You probably don't have a short or your SWR would be so bad you probably would have damaged the radio. I don't trust CB antenna tuners for that high of a frequency check. Try to find a tuner more suited for the range you want to check.

Where did you place the antenna? Is it near a large metal area on the side of the Antenna? Do you have a decent ground plane? Did you try playing with the length of the antenna? There should be some room to move it up or down. Try to shorten it a tiny bit to see if that helps. But don't cut it! Just tune it at 146.00 MHz. That is the middle of the 2M spectrum.

One last thought. That antenna is good for a freq range from 136 to 512 MHz. In order for it to function across that large of a spectrum, it just might be the best you'll get on 2m.

[CVD]

Roger, Russ & Scott - thanks for your ideas yesterday. I moved the bracket up, so the base of the antenna is now right at the top of the tub. SWR readings are now acceptable throughout the 2m range

144.000 – 1.9
145.000 – 1.7
146.000 – 1.4
147.000 – 1.2
147.995 – 1.2

I might play with the antenna position via the set screws a little more (about 3/8” of adjustment available), but I’ve got a workable radio now. Next, I need to figure what to do with those holes I drilled for the original bracket position (plus, I have to read the manual and figure how to use the radio).

[Zoobi]

I'm glad that worked out for you. Can you still get into the garage?

Keep the manual in the jeep when you finish. A year from now when you want to do something out on the trail, you wont have to fumble with the settings.


Scott

[Roger]

Wow! That is a big difference! Scott's advice regarding the manual is the best advice ever!
I forgot to look at your radio! Most of the are a pain to program, so I recommend buying the software to do it.

[Materdaddy]

I don't recommend buying any software. I recommend buying a cable, and using chirp: http://chirp.danplanet.com/projects/chirp/wiki/Home

It's free and works on TONS of radios and is completely cross-platform. I use it for all of my radios, including a 271a which is probably an older version of your 281a. Chirp lists your 281a as supported.

[Roger]

Never heard of it, going now to check it out - Thanks Mat!

[Roger]

I don't recommend buying any software. I recommend buying a cable, and using chirp: http://chirp.danplanet.com/projects/chirp/wiki/Home

It's free and works on TONS of radios and is completely cross-platform. I use it for all of my radios, including a 271a which is probably an older version of your 281a. Chirp lists your 281a as supported.

I'm going to start a new thread regarding this! Thanks Mat, this is good stuff.