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Two Failures of Z11 Pro II


William WY7WL
 

Hello,?

I've had two failures of the Z11 Pro II tuner this year (smoke and burning electronic smell). Both purchased new from DX Engineering. The first one failed within 2 days and now the second one failed about 2 months in. I'm using the icom cord from my IC7100 to power the tuner. I've checked the voltage coming from that cord (13.5V). I've checked the antenna for the band in use and it was about 4:1 SWR. This week I noticed the tuner would tune only if I forced a full tune of the unit.

So the question is...could I be doing something wrong or have I received two bad units?


 

I "burned up" an LDG Z11Pro II. I put too much wattage through on 6 meter FT8. Apparently it should have been less than about 30 watts. I used 100. It would not tune. A buddy opened it up. At least 2 of the toroids were 1/2 black (heat) and a relay was blown. He replace the relay and it now tunes, but I cab" put it into bypass.
Don't know if this helps, but you aren't the only one to injure a Pro II.


 

Rick,

I'm surprised that you didn't also smoke your TX, as almost every 100-W TX out there has to be "derated" to 25-30 W for continuous-duty service. Almost every autocoupler is the same.

Want an inexpensive rig rated for 100% TX duty cycle. Check out the venerable IC-718. (If I remember correctly :)

Regards,

--Kirk, NT0Z

P.S. My LDG tuners "temporarily fail" (or at least "get stupid") when they are exposed to temps below about 10 F. Z11, RT-100, etc. It's in the manual...in the fine print! I have to put them in heated boxes to use them outside or in the attic space.

My book, "Stealth Amateur Radio," is now available from www.stealthamateur.com and on the Amazon Kindle (soon)


On Friday, February 11, 2022, 02:29:15 PM CST, Rick Hatton <doxieguy.71@...> wrote:


I "burned up" an LDG Z11Pro II. I put too much wattage through on 6 meter FT8. Apparently it should have been less than about 30 watts. I used 100. It would not tune. A buddy opened it up. At least 2 of the toroids were 1/2 black (heat) and a relay was blown. He replace the relay and it now tunes, but I cab" put it into bypass.
Don't know if this helps, but you aren't the only one to injure a Pro II.


 

Kirk,
I routinely run my 991a at 75-80 watts into a MFJ 994E turner for FT8. I might scale it back. I do believe I was using the 991a when I smoked the Z11 Pro II. A stray jolt from a lightning strike took out the CAT interface on my 718. CAT is the only thing that isn't working.

Edit - I did just turn it down to 50.


William WY7WL
 

I noticed some of the other LDG tuners have a 10 W digital limitation however this one definitely does not. I wonder if it was omitted in the instruction manual??


 

On Fri, Feb 11, 2022 at 04:59 PM, William WY7WL wrote:
I noticed some of the other LDG tuners have a 10 W digital limitation however this one definitely does not. I wonder if it was omitted in the instruction manual??

I have 2 manuals.
One (Rev B) says :0.1 to 125 watts SSB and CW peak power, 100W on digital modes and 6 meters.

The other (Rev A) says: .1 to 125 watts SSB and CW peak power, 30 watts on PSK and digital modes, and 100 watts on 6 meters.


William WY7WL
 

Very interesting?


 

That IS interesting. Wonder if one's a typo or something unintended? I'd be wary about running digimodes above 30-40 W.

My autocouplers seem to die from lightning events... :)? I have two SGC units that are toast until I get 'em fixed.

--Kirk, NT0Z

My book, "Stealth Amateur Radio," is now available from www.stealthamateur.com and on the Amazon Kindle (soon)


On Friday, February 11, 2022, 06:38:14 PM CST, William WY7WL <lipscomb724@...> wrote:


Very interesting?