Tuning the Larsen BSA 450-K for GMRS
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- Опубліковано 22 лют 2021
- Tuning the very well made Larsen BSA 450-K collinear 5/8 over 5/8 wave base antenna for GMRS. This is a small, low profile base antenna that has a very small wind load with 4.5 DB of gain.
This antenna is available from several retailers, but I purchased this one from ebay. www.ebay.com/itm/New-Pulse-La...
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Hmm maybe a dremel would be quicker, will try when I tune an antenna.
Nice video!
Yes it would. My old corded one died and it's battery powered replacement is garbage. I have an old table top grinder for the fine tuning.
Using a Dremel tool with the cutting blade is much easier and neater.👍
Yes, I would have been much easier.
I just got that same one from ebay as well.in process of tuning it right now what a perfect video to come across how is it do you like it does work well for you.
Yes, it is working well. I did end up cutting it some more to get the SWR down to 1.0.
You said its a 5/8 over 5/8... Does that mean both the top element and the bottom element are each 5/8 wave? And if so, why only trim the bottom and not the top? I'm just trying to learn what's going on here.
Yes, both sections are 5/8 wave each and I had the same question about only trimming one element as it seems logical to trim both the same. The directions for this antenna were rather clear to only trim the bottom section so I complied.
Math doesn't lie
I tune my GMRS antennas for resonance at 465 mhz..if I was not using repeaters, I would go for 462.
I ended up tuning it for the middle. Had to go to 8 1/4, like it said, to get a 1.0:1 on 467. Still was 1.0:1 on 462 so I'm happy.
@Brittney Kaid Thank you for teaching her all those tricks. She tuned my antenna perfect.
Now if you tune with rg-58 then switch to a different type of cable lmr-400 or change length your swr will change, correct?
Yes, SWR did move some after changing coax type and length. Was under 1.4:1, but still a change. Is best to use the final mount and coax to tune.
Did you lay the ladder down on the ground before every test? I will make a difference.
I retracted the ladder, but was still up. Had about 3-4 foot gap between them.
What kind of range do you get simplex with that? (Power?) Do you know how it compares with a dedicated base antenna?
At 25ft up with 4 watts I'm getting maybe 2 miles. I have many oak trees and neighbors with 2 story houses. If I could get the base of the antenna 40-45ft up to get over the trees the range should be 5+ miles.
@@Soladaddy are you using just an HT? I get into a repeater 30 miles away with my magnet mount on my mobile with my 5 watt HT?
I have a Browning ,450 - 5/8 over 5/8 . Gmrs I got a 1:01 match is that good .please answer.thank you
1.01 is excellent. Most say anything under 1.5 is great.
@@Soladaddy great it is my first time turning one . I served in the military but only talk on our radios .thank you for your reply back
i use bolt cutters
I tried some large snips for sheet metal but that whip is tough. Now have a new Dremel tool for the next one.