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#1
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Hi,
Any recommendations on a good, or bad, tuner for use with balanced antennas? That is, one which does not use a balun? It doesn't need to be an auto-tuner. There are a few from small suppliers, and I see the MFJ in their latest catalog has what is touted as a modernized Johnson Matchbox. -- Alan WA4SCA |
#2
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You'll need at least a choke type balun to get from the unbalanced tx output
condition to the balanced antenna load unless you go with a link-coupled tuner. Link coupling removes the necessity of using a balun since there is no "direct" connection between the unbalanced tx output & the balanced antenna load. "Alan P. Biddle" wrote in message ... Hi, Any recommendations on a good, or bad, tuner for use with balanced antennas? That is, one which does not use a balun? It doesn't need to be an auto-tuner. There are a few from small suppliers, and I see the MFJ in their latest catalog has what is touted as a modernized Johnson Matchbox. -- Alan WA4SCA |
#3
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MFJ's description of their "balanced" tuner might be describing a
conventional unbalanced tuner with an effective choke. Does anyone know what is inside? 73 Mac N8TT -- J. Mc Laughlin - Michigan USA |
#4
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On Sat, 25 Oct 2003 13:44:12 GMT, Alan P. Biddle
wrote: Hi, Any recommendations on a good, or bad, tuner for use with balanced antennas? That is, one which does not use a balun? It doesn't need to be an auto-tuner. There are a few from small suppliers, and I see the MFJ in their latest catalog has what is touted as a modernized Johnson Matchbox. You can download the manual he http://www.mfjenterprises.com/man/pdf/MFJ-974H.pdf Danny. K6MHE |
#5
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T.E.O wrote:
These are fairly easy to build. Basically 2 homebrew coils, a variable capacitor & a choke balun made of coax. FYI, this is an ASCII newsgroup - no binaries allowed. -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
#6
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On Sat, 25 Oct 2003 13:44:12 GMT, Alan P. Biddle
wrote: Hi, Any recommendations on a good, or bad, tuner for use with balanced antennas? That is, one which does not use a balun? It doesn't need to be an auto-tuner. There are a few from small suppliers, and I see the MFJ in their latest catalog has what is touted as a modernized Johnson Matchbox. I'm having good luck using an unbalanced tuner, an mfj989c, with an external choke balun (a few turns of coiled coax), to transition to a dipole fed with 450 ohm line. I can tune my 44-ft. dipole on all bands, 30 thru 10. As far as balanced tuners go, Palstar and Bliss make real expensive ones, in addition to the mjf model you just mentioned. Don't know of any others currently being marketed. Bob k5qwg |
#7
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A look at the published schematic for the MFJ974H (Revision 7, dated
10/24/03) shows a balanced topology fed by a "choked" piece of coax (on the transmitter side). One might call it a Capital I arrangement. The vertical is a step adjustable inductance. Two ganged capacitors (four sets of plates, each nominally 10-208 pF) are on each side of the inductor. (one gang on the left and the other on the right) Choked transmitter comes in on the left and antenna is connected on the right. No means for discharging accumulated charge appears to be provided. [ I would place something like a 470 k ohm resistor to common from each of the antenna terminals.] It will be interesting to learn how this unit performs in the field. 73 Mac N8TT -- J. Mc Laughlin - Michigan USA |
#8
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![]() Check out the following URL for lots of "candid" comments about Tuners and other amateur radio equipment: http://www.eham.net/reviews/?ehamsid...4beaaa31ac6ce6 VA3KAI, Al "Alan P. Biddle" wrote in message ... Hi, Any recommendations on a good, or bad, tuner for use with balanced antennas? That is, one which does not use a balun? It doesn't need to be an auto-tuner. There are a few from small suppliers, and I see the MFJ in their latest catalog has what is touted as a modernized Johnson Matchbox. -- Alan WA4SCA |
#9
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Alan P. Biddle wrote in
: Any recommendations on a good, or bad, tuner for use with balanced antennas? That is, one which does not use a balun? It doesn't need to be an auto-tuner. There are a few from small suppliers, and I see the MFJ in their latest catalog has what is touted as a modernized Johnson Matchbox. I thought if your antenna is balanced then you don't need a tuner or balun. |
#10
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On 28 Oct 2003 21:46:17 GMT, Michalkun wrote:
I thought if your antenna is balanced then you don't need a tuner or balun. How do you suggest to connect your transmitter's unbalance output to a balanced antenna system? Danny K6MHE |
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