FLex-1500 ATU

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  • Updated 3 weeks ago
  • (Edited)
I am going to acquire a Flex 1500 to play with on my frequent business trips.  

Can someone recommend a decent ATU that I can use with end-fed wires either chucked out of a hotel window or draped around a hotel room.

I do have an Elecraft T1 knocking about somewhere.  Would that be a suitable match?

Thanks, David G4NRT/Z21NRT

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David G4NRT / Z21NRT

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Posted 3 weeks ago

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Richard McClelland, AA5S

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I used a Dentron Jr. Monitor tuner with my Flex 1500 for several years.  Worked great, except that it doesn't auto-tune.  The Elecraft KAT-500 works well with the Flex-1500 with the caveat that you'll need a small amplifier to get at least 10 watts into the tuner in order for it to auto-tune.  Neither of these tuners may be what you are looking for due to their size.  You can find more detail about the Dentron Junior Monitor here: https://outbackofbeyond.wordpress.com/2015/12/19/dentron-jr-monitor/  Maybe others can offer suggestions about smaller antenna tuners than these two.
(Edited)
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David-N5PSM

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As I understand.....
The Flex 1500 will put out 5W and the tuner you have on hand will work from 500mW to 20W.
....I think you are good-to-go
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Richard McClelland, AA5S

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The KAT-500 sometimes auto-tunes on 5 watts but if the tuner memory hasn't been set and the tuner needs to do a full auto-tune, the auto-tune won't commence unless I turn on the amplifier.  Once I kick start the auto-tuning with the amplifier, I can immediately turn it off and the tuner completes the auto-tune.  I've had the KAT-500 for five years or so, maybe I should update the firmware and see if the auto-tune performance has been improved with a subsequent update.  
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Andrew Russell

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David,
In the unlikely event that the T1 doesn't workout LDG have a line of low power and QRP tuners that have a wide range of matching. I have used an original Z100 with my F1500 from the beginning.
Although made for coax lines like the T1 you may need a balun for unbalanced antennas. I often put the tuner at the base of the antenna and plug a banana plug into the antenna connector. Works fine.
Andrew VK5CV.
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Dudley - WA5QPZ, Elmer

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David,
The Flex1500 is very forgiving about output impedance,  open or shorted really does not matter,  I think that the PA is way over engineered to be able to absorb just about any mismatch.   The tuner may be good for RF bandpass,  but really not needed with the 1500,  it will not roll back as it can not message SWR anyways..   Designed just for the kind of service you are planning,  QRP into any kind of antenna.  

Have fun,
73,
Dudley
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Richard McClelland, AA5S

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I didn't know that.  I have a delta loop that I can't match on the low end of 80 meters, I think I'll give it a go without the tuner and see what happens.
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David G4NRT / Z21NRT

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Many thanks to all those who kindly responded. I’ll give the T1 a whirl first I think as it is so compact. 73! 
(Edited)
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David-N5PSM

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Sounds Like a good plan,  I have been working with a Flex6300 from a hotel room since 2013.  I use a Balun Designs 9:1 UnUn and a long wire (26 AWG ) out the A/C vent.  56 Countries.
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Phil N3ZP

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When I owned a Flex-1500 I used an LDG Z-11Pro II tuner, It has very wide range and can be run on AA batteries by installing a battery holder. It tuned my 43 ft vertical and also worked with various wire antennas for Field Day. 
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Dudley - WA5QPZ, Elmer

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David,

Just one other thing if you have not used PowerSDR before on a FlexRadio.  The AGC-T control should be your most used control of the radio,  the setting to the "sweet spot"  ,  background noise is minimized verses the audio,   you will move it alot..  

Enjoy,
73,
Dudley