KE9ZM
06-19-2009, 02:37 AM
For about the past year I have been using the LDG AT-200 Pro Autotuner. A link to the full review that I wrote shortly after I got the LDG autotuner is provided below.
After a year of use, here are some final thoughts on this tuner.
Why did LDG make a 250 Watt mode?
Why did LDG make a 250 Watt model? Just about every HF radio manufactured at the time of this writing is 100 watts. There are exceptions, but those mid-class to upper end models with more than 100 watts already have a built-in antenna tuner. So you really would not even need an outboard antenna tuner like the LDG for these radios.
If you have a linear, then 250 Watts is the wrong size - linear. Going from 100 Watts to 250 Watts is slightly more than a 3db increase. If 1 S-unit is 6 DB then going from 100 Watts to 250 Watts is about 1/2 an S-Unit. That will make no real difference at all at the receiving end.
Tuner resolution and LED power readout
The LDG uses lumped C and L. As such, the tuning will not be continuous. "SWR tweakers" will never be satisfied. With an air dielectric variable capacitor and/or rolller inductor - you can get nearly an infinite number of combinations.
Again, like going from 100 watts to 250 - which does not make a difference, trying to get a SWR lower than about 1.5 is not going to make a difference. For 100 watts, at a SWR of 1.5 you are only losing a couple of watts - and that does not make any material difference. But it's hard to convince "perfect SWR tweakers" of this.
The other issue is the power out LED resolution on the LDG AT-200 Pro. It is just too gross to be valuable. See my review for the details on this.
Final Recommendation
Bottom line, if you are going to buy an LDG autotuner and you have a 100 watt out radio I think you would be better off with the LDG AT-100 Pro.
The LDG AT-100 Pro is about $25 less than the LDG AT-200 Pro. It's not really about saving money, its about the right "fit" for a 100 Watt radio.
I don't know what market segment LDG is targeting with the 250 Watt model. It does not seem to be a good "fit" for any HF radio being manufactured today - typically 100 watts out; or a good fit for any linear that makes sense.
Here is my review from last year
http://frrl.wordpress.com/2008/08/03/review-of-the-ldg-pro-200-autotuner/
Here is the LDG Electronics product line
http://www.ldgelectronics.com/index.php
After a year of use, here are some final thoughts on this tuner.
Why did LDG make a 250 Watt mode?
Why did LDG make a 250 Watt model? Just about every HF radio manufactured at the time of this writing is 100 watts. There are exceptions, but those mid-class to upper end models with more than 100 watts already have a built-in antenna tuner. So you really would not even need an outboard antenna tuner like the LDG for these radios.
If you have a linear, then 250 Watts is the wrong size - linear. Going from 100 Watts to 250 Watts is slightly more than a 3db increase. If 1 S-unit is 6 DB then going from 100 Watts to 250 Watts is about 1/2 an S-Unit. That will make no real difference at all at the receiving end.
Tuner resolution and LED power readout
The LDG uses lumped C and L. As such, the tuning will not be continuous. "SWR tweakers" will never be satisfied. With an air dielectric variable capacitor and/or rolller inductor - you can get nearly an infinite number of combinations.
Again, like going from 100 watts to 250 - which does not make a difference, trying to get a SWR lower than about 1.5 is not going to make a difference. For 100 watts, at a SWR of 1.5 you are only losing a couple of watts - and that does not make any material difference. But it's hard to convince "perfect SWR tweakers" of this.
The other issue is the power out LED resolution on the LDG AT-200 Pro. It is just too gross to be valuable. See my review for the details on this.
Final Recommendation
Bottom line, if you are going to buy an LDG autotuner and you have a 100 watt out radio I think you would be better off with the LDG AT-100 Pro.
The LDG AT-100 Pro is about $25 less than the LDG AT-200 Pro. It's not really about saving money, its about the right "fit" for a 100 Watt radio.
I don't know what market segment LDG is targeting with the 250 Watt model. It does not seem to be a good "fit" for any HF radio being manufactured today - typically 100 watts out; or a good fit for any linear that makes sense.
Here is my review from last year
http://frrl.wordpress.com/2008/08/03/review-of-the-ldg-pro-200-autotuner/
Here is the LDG Electronics product line
http://www.ldgelectronics.com/index.php