[Elecraft] Question about forthcoming KAT500

[Jim Bennett]

An interesting question!! And it directly affects my situation, too.

So, here is a slight add-on to Phil's query - perhaps Eric or Wayne can shed some light here. My "main" antenna is an 88' foot long doublet at 45 feet, fed with 600-ohm ladder line, and a 1:1 balun where my eight feet of coax from the K3/100 connects to the balanced line. The K3's tuner gives me a match on this antenna on 80 through 6 meters. I'm a happy camper with this antenna working pretty darn well on all bands, although it is mostly NVIS on 80. So, my question is - how close in performance will the KAT500 be to the KAT3? Can I expect the KAT500 to match this antenna as well as the KAT3 does? I'd certainly NOT be happy to spend the dollars for the new tuner to find that it is not capable of doing what the KAT3 can do.

Jim / W6JHB


On   Saturday, Dec 31, 2011, at  Saturday, 12:33 PM, Phil Hystad wrote:

> Did I read right that the forthcoming KAT500 would be able to match up to a 10:1 SWR?
> 
> So, this should mean that the impedance range of the tuner is anywhere from 5 to 500 ohms (absolute value of Z).
> 
> I currently use an AT1KM tuner with impedance range of 20 to 1500 ohms.  I use this with a horizontal delta loop and I am able to match all of my important bands that I operate on this antenna which are 80, 40, 30.  I use a 5-band hex beam for the other bands.
> 
> But, I can easily get a good match well under 1.5:1 using the AT1KM.  But, I also measured the impedance and SWR at the point that the coax hooks into the AT1KM.   These measures are then of the raw, un-tuned, antenna system (coax and delta loop) made with my MFJ-259B.  According to these measurements, the raw impedances I need to match are more then 10:1 for some of the bands.  Indeed, I am close to 24:1 for the low part of 80 but I operate fine in this region using the AT1KM.
> 
> Should I then assume that the KAT500 will not work for me with my current antenna system?  I also noticed that other auto-tuners have similar wider ranges.  For example, MFJ-998 supports a matching range of 12 to 1600; and, the old Palstar AT-Auto supports a matching range of 15 to 1500 (now Kessler Engineering).  Apparently, the new the new Palstar HF-Auto is reported as 10:1 SWR which may be the same as KAT500.
> 
> Therefore, can someone (Wayne, Eric or others in the know) confirm that with my current antenna configuration, I will probably NOT be able to use the KAT500 for 80 meters (at least).  My options I suppose are not to use the KAT500 at all, not use it for 80, or reconfigure my delta loop (although, my degrees of freedom for this are small).
> 
> 73, phil, K7PEH
> 
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