Tuner issue 6600

Ulrich Gonter-Linz, DG7NFX

Still Problems with the internal Tuner Flex 6600 - it tunes but SWR often not OK after tuning cycle. When will this be fixed?

Steve - G8KNC

I have that issue with my 20-foot long wire.  I had hoped for a 1:1  match with the internal tuner, but it does seem to struggle! 

Neil Friedman

Steve, that;s a pretty short "long wire."  Not even a half wavelength on 20 meters.  I'm guessing its untuned SWR on most HF bands is pretty high.  Do you know what the untuned SWR is on your bands of interest?

Patrick

Some times and even with a 3:1 or less SWR the antenna will not tune because one of the two factors inductance or capacitance are out of the range of the internal tuner. In a case like that you can change the length of the feed line to the antenna to help adjust one of the two factors, to lower or increase them. Typically the built in tuner is ok to tune fairly resonant antennas where they are none resonant at band edges. Random length antennas are problematic in that the inductive/capacitive values will be extreme and out of range of the tuner. You will need to do some experimentation with feed line and/or antenna length to bring the values into range that the tuner will tune. You may have to go to the expense of a WIDE range tuner like a Palstar tuner. Hope that helps. Please note that Even when tuning your random length for a specific band may not work for all bands.

Patrick

More:  If flex tightened the limits, and I think they did, it was to make sure that the high current and voltages that are present when the antenna tuner is tuning don’t destroy components in the tuner.  It may be that they noticed an uptick in repair returns due failed components.

N8AUM

If my memory is correct from what I have found reading couple gazillion post is that it is a known issue with the ATU. Sometimes it takes 5 attempts before it's happy with mine.

Neil Friedman

I suspect Steve is starting at 10:1 or some such.  Doesn't give the ATU much of a chance.  

N8AUM

I upgraded to 3.1.1.12 today and tried the ATU and it seems to be working OK now but yes, theirs only so much it can do. 

Patrick

I would characterize this situation as a complaint rather then a problem.   The tuner works within the limits set by the designers.  If the tuner can’t tune the antenna, then it is a antenna/feed system fault that needs to be looked into.  If you intend to use antennas with limits beyond what the tuner can tolerate then work on the antenna.  There are ways to  adjust the antenna to make it work with the tuner.  Or buy a true wide range tuner.  

Neil Friedman

My ATU works like a charm, but the max starting SWR on the antennas/frequencies I tune are no more than 2.5:1.  

Patrick

Even with a 3:1 or better SWR,  if the inductive or capacitive values are not optimal, and that can cause excessive current or voltage on those parts, the tuner will protect it’s self.  Adding or subtracting some coax length can cure that issue. Due to the nature built in antenna tuners,  the available inductors and capacitors are limited in sizes that they can fit into the limited space of the radio.  A dedicated tuner will have much heavier and a wider range of value, that will reach a matching solution, with better probability of success.  

Bob Needleman

I fully agree with Pat's comment about the limitations of  internal ATU's built into all the HF/6M transceivers, regardless of brand. Personally, I never use mine and rely on my trusty  legal limit external ATU, since I sometimes run an amp. Any of the full-sized manual or auto tuners currently on the market will be able to handle fairly high impedance mismatches and allow you to get RF into the antenna. They're not magic, but they will definitely work better than internal ATU's, especially if you have a non-resonant antenna(s)  with inherently high SWRs. 

Bob K3AC