The Z100 and Z11 are both microprocessor controlled auto atu's. The Z100 is often seen alongside the 817 so i wanted to see how well these atu's worked with the 817. Please note the tests i did were only of interest to me along with the 817 radio.
Above is the z100
How did i find it? Well first off it worked as it should in it searched and found a match using my 817 along with a loop antenna. There were a couple of things i didn't like. Ill explain, First i needed to key up . I set the 817 to roughly 2 watts but all i got was a "no rf present" indication on the led's. I found it only worked with my 817 using the full 5 watts. Ok this is fine with a 100 watt radio but this is full power out on an 817. So i keyed up on 5 watts then had to press the tune button for a few seconds. It found a match in about 5 or 6 seconds. Not good..Thats 9-10 seconds at full power out into a missmatched load. Memory recall was not instant and again required a keydown before a medium press on the tune button then the atu would try and find a stored setting, again a couple of seconds tuning on full power out even for a "stored" match.. It has the advantage of being small and an internal battery can be used for /p and along with a 100 watt radio whereby using 5 watts to tune wouldn't be a problem this would be a good little piece of kit. The Z100 has a stated power range 0f 0.1 -125 watts on hf with a reduced power and matching range for 6m. Do i like it ? yes , but not with an 817 unless of course tuning on full power is not an issue , which for me it is.
Above is the Z11 pro
I used to own the LDG AT100 pro and was very pleased with it which is very similar to the Z11 so i decided to try the Z11 along with the 817 and see if it was more 817 friendlier than the Z100.
First off the Z11 tuned using 500mw from the 817 which is good news for those of us trying to be kind to the outputs of our 817's. Tuning seemed a little faster than the Z100 and did not require any pre keydowns before hitting buttons as did the Z100. I simply set the power out to 500mw on cw and hit the key. once tuning was done and stored memory recall was almost instantanious as it is with the AT100 pro i used to have. This atu is a little more versatile as it can then be manually adjusted using the front inductance/cap buttons to " trim" any matches found but this as with my old AT100 pro these buttons were very rarely needed .As with the Z100 the Z11 can also be fitted with an internal battery for /p work. The stated power range is 0-125 watts on hf with a tuning range of 6-1000 ohm with both these values reduced for the 6m band.
So as far as which i feel is better for use with the 817 there is a clear winner in the Z11 pro.