Saturday, June 4, 2016

A slight change of plans.....

The test setup 
I was out today once again with my portable operations but this time there was no on air time it was time to test and decide. I went out with my MFJ antenna analyzer, mobile whip antennas and various lengths of counter poise. I wanted to see where my 20m mobile whip antenna was resonant and using the MFJ analyzer was the easiest way of doing this. The counter poise for 20m I started with was 17.5 feet long and the SWR was not showing it was resonant in the CW portion of the band but in the SSB section. So I found I have to lengthen the counter poise to 30 feet to get the SWR to 1.2:1 in the CW portion of 20m. This got me to thinking if the mobile whip was the way to go, I did have these antennas hanging around and I wanted to give them a go to see what results I would get. They are still very useful to me when I operate portable mobile from the car and they preform very well in that situation. I wanted to try the whip  antenna as I felt it would be a very small footprint of an antenna but with a counter poise of 30 feet the footprint is larger than I would like. From most of my blog reading about portable trail operation, NPOTA operations and just plan old out in the park for the day operation hands down most of the time the antenna of choice was one of LNR's par end fed antenna's.   I have looked over the antennas at LNR Precisions site and not sure yet which antenna to get, I am leaning toward the EF-20 as it's not as long (33') as say the other models. I'm really not going to use 40m and I figure (but not sure) I can use the Elecraft KX3's tuner to operate 15 and 10M?? Any feedback about this antenna or others would be appreciated.

2 comments:

  1. Hi Mike. If you need a 30 foot counterpoise wire for 20M ops with a whip, you might as well go for a 33 foot LNR end-fed for that band. No tree? One of those portable fiberglass poles might do. I have tried tuning my EF-20 on 17M...no match possible. Managed on 30M with a close match at 5 watts. But results disappointing. Small MFJ tuner. 73 Dick

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    1. Good morning Dick and very nice to hear from you, I have sent a question out to the guys at LNR regarding the best choice for my situation andI am just waiting to hear back from them. As for tuning the EF-20 on the site I noticed (after putting up my post) they recommend to not tune the antenna. As I read they explain that the antenna is meant only for the band it was manufactured for. By using a tuner possible damage can come to the antenna.
      73,
      Mike

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