Backpacking Tuner

Started by RangerMobile, October 03, 2014, 09:02:53 PM

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RangerMobile

Can anyone recommend a tuner for the Yaesu 857D? I plan on backpacking this unit into the mts. using a Radio Oasis Diapole inverted "V".

Do I really need another one??

I have the LDG YT-100 in the Shack.

Thanks   

Lamewolf

Quote from: RangerMobile on October 03, 2014, 09:02:53 PM
Can anyone recommend a tuner for the Yaesu 857D? I plan on backpacking this unit into the mts. using a Radio Oasis Diapole inverted "V".

Do I really need another one??

I have the LDG YT-100 in the Shack.

Thanks   

I would recommend an MFJ-902B travel tuner.  It doesn't require batteries, and when operating in the field the antennas sometimes have wild impedance swings depending on deployment configuration and a manual tuner will have a much broader matching range than any auto tuner.

gil

The Elecraft auto tuner is great and pretty small, but you would have to turn power down to 25W, which you might want to do anyway to save batteries...

Gil.

Lamewolf


I built a mini T match tuner for field use and it has tuned any antenna I've connected to it so far - random wires, end fed half waves, verticals, mobile whips etc and its very compact.  You can see it here:
http://www.angelfire.com/electronic2/qrp/minit.html


cockpitbob

I've always been a 1/2wave end fed guy.  My 63' wire will match reasonable well on 40/20/15/10 with a simple SOTA type match.  Recently I spent 2 weeks on the 4th floor of a hotel with my QRP rig.  I brought a T-match tuner (much like Lamewolf's) and little 9:1 unun..  It was wonderful.  I let a 25' piece of wire hang out the window and with it laying against the side of the building I could get a good match on 80/40/30/20.  I like the simplicity and "purity" of resonant antennas, but it was really nice to be able to force a match under awful conditions.  I just ordered parts and am going to build one in the smallest enclosure I can and pair it with my MTR rig.

gil

QuoteI've always been a 1/2wave end fed guy.

Me too. Most of the end-fed tuners available are QRP though, limited to 5-25W. The 857D is a 100W radio... A 100W end-fed tuner could be made easily enough though...

Gil.

cockpitbob

Quote from: gil on December 12, 2014, 11:58:19 AM
QuoteI've always been a 1/2wave end fed guy.

Me too. Most of the end-fed tuners available are QRP though, limited to 5-25W. The 857D is a 100W radio... A 100W end-fed tuner could be made easily enough though...

Gil.
I made my own coupler for my 857D.  It's a unique design slightly different from LNR's that has a separate primary winding, no capacitor and requires a 6' counterpoise since the coax is isolated from the output winding.  It's fine at 100W.  Lately I've had the 857D in my office and have been using this with a 63' wire as my main antenna.  I'm limited to 40/20/15/10, but I love changing bands without retuning anything.

I should write up that design some day.  I would love to see how it compares to LNR's.

Lamewolf

Quote from: gil on December 12, 2014, 11:58:19 AM
QuoteI've always been a 1/2wave end fed guy.

Me too. Most of the end-fed tuners available are QRP though, limited to 5-25W. The 857D is a 100W radio... A 100W end-fed tuner could be made easily enough though...

Gil.

A simple Lmatch tuner with a series coil and a shunt capacitor works wonders matching an endfed halfwave.  You could even homebrew a coil that would handle 100 watts easily, or even try the MFJ-16010 Random Wire Tuner which is an Lmatch tuner rated for up to 200 watts and very compact.