n9xfx
New Member
Posts: 1
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Post by n9xfx on Apr 27, 2008 20:56:37 GMT -5
Looking for some help. I just installed a model 200 Tarheel on my car. With the provided Matching Coil I get great SWR on 75 meters, 20 meter and above. However on 40 meters it's 3:1 SWR. I stretched the coil as instructed by Tarheel and seen an improvement to 2.5:1 on 40, but now the best I can get on 75 is 2:1. What I think I need is a switchable Feed Point Matching system. Something that has a coil for 40 meter, and one taylored for 75 meters. Any ideas?
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Post by W9GAS Gary on Feb 2, 2009 17:52:27 GMT -5
Check out this mobile operating website: www.K0BG.comIt is not unusual to find the match to not be exactly the same on 75m and 40m. The fact that you have it fairly low in both cases is good. There really is no need to get the MFJ switchable inductors. I use a single 12 ga. bare copper wire wound to form 9 turns on a one inch coil form. I used an alligator clip on one end and tapped the coil while using my MFJ 259B antenna analyzer. I found a reasonably good match on 40 and somewhat less on 75m. I look for the dip on 75 and stop tuning my HiQ 4/80. I do not use the autotuner on the TS440SAT. Alan Applegate's website is THE site for mobile operators. Check out the section on matching the antenna. There is much to be learned from this website. 73 de Gary W9GAS Cookeville TN |
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