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eHam Forums => Antennas and Towers and more => Topic started by: N2LWE on February 08, 2013, 06:21:00 PM



Title: External tuner on a Yaesu FT-950
Post by: N2LWE on February 08, 2013, 06:21:00 PM
I just purchased an FT-950 and the internal tuner couldn't match the vertical I'm using so I tried to connect the external tuner I used on my FT-840 with no problem but it doesn't seem to work at all even though I connected it the same way I had it on the 840. Can anyone help. New radio and haven't been able to transmit yet. If I key the radio the "high SWR" light comes on.


Title: RE: External tuner on a Yaesu FT-950
Post by: VE3PP on February 09, 2013, 07:49:42 AM
I just purchased an FT-950 and the internal tuner couldn't match the vertical I'm using so I tried to connect the external tuner I used on my FT-840 with no problem but it doesn't seem to work at all even though I connected it the same way I had it on the 840. Can anyone help. New radio and haven't been able to transmit yet. If I key the radio the "high SWR" light comes on.

Some questions need to be answered so we can help you.

First. what vertical are you using? The SWR must be high if the internal tuner of the FT-950 will not tune it. However you must remember that the internal tuner is rated for 3:1 or under SWR's on antennas. I have tuned higher SWR's than 3:1 but don't count on it doing that.

Second, what external tuner are you using? Any radio/tuner combo will work. The radio has no effect on the external tuner other than putting power through that tuner.

I have a Palstar AT1500 in line with my FT-950 and it works fine, and I have other tuners in line that worked just fine.

Third. make sure the internal tuner is off when using the external tuner.

Fourth, if you have engaged the internal tuner did you hold the TUNE Button long enough for the tuner to actually try tuning the vertical? You need to hold the Tune button long enough to engage the tuner. If the tuner will not handle the SWR it just shuts off. If it can it will cycle through until it gets the SWR down low enough to operate the radio.

Any other questions feel free to email me. I have owned my FT-950 for some time so I might be able to assist you further.

Rick VE3FMC


Title: RE: External tuner on a Yaesu FT-950
Post by: N2LWE on February 09, 2013, 09:25:23 AM
Yes I have held in the tuner button in long enough. It cycles through real fast and if I key up, the light comes on "high swr". The tuner is an MFJ-969 and the antenna is a Hy-Gain DX77A


Title: RE: External tuner on a Yaesu FT-950
Post by: KH2G on February 09, 2013, 11:33:59 AM
Make sure you disable the internal tuner when using the external or they will interact and may never get a match.
Other than that, tune into a dummy load and make sure the tuner is working.
73
Dick KH2G


Title: RE: External tuner on a Yaesu FT-950
Post by: W6GX on February 09, 2013, 03:20:55 PM
I have owned both the FT-950 and FT-840.  The internal tuner in the 840 could tune up to a SWR mis-match of 10:1.  The 950 could do 3:1 at best.  The tuner in the 840 uses variable capacitors and the design is different from the one in the 950.  I hope this helps.

73,
Jonathan W6GX


Title: RE: External tuner on a Yaesu FT-950
Post by: W4OP on February 09, 2013, 03:32:24 PM
Yes I have held in the tuner button in long enough. It cycles through real fast and if I key up, the light comes on "high swr". The tuner is an MFJ-969 and the antenna is a Hy-Gain DX77A

Why do you need an external tuner with the rig? That antenna should give you reasonably low VSWR even w/o engaging any tuner.

Dale W4OP