[Elecraft] KAT500 actual radiated power during tuning

[K5MWR]

A technique that works well using a dummy load to adjust a tuner is to 
set up a bridge configuration where the dummy load absorbs the power and 
the tuner is used to balance the bridge.  Once done the dummy load is 
switched out and rig drives the tuner.  Electric Radio use to sell a 
bridge like this that I have used with my Drake amps for years and 
really nice way to minimize QRM.

Dave K5MWR


On 11/6/2017 5:52 PM, Don Wilhelm wrote:
> Erik,
>
> I don't know the workings of the Icom tuner, but the KAT500 needs 20 
> watts input to tune.  All of that goes to the antenna.
>
> If part of that signal would be shunted to a dummy load, I don't think 
> it would be tuned to the correct antenna impedance.
> I would have to know more about the configuration involved, but to my 
> mind, it sounds like a dummy load is being connected in parallel with 
> the antenna which would upset the impedance to be matched.
>
> 73,
> Don W3FPR
>
> On 11/6/2017 6:37 PM, E T wrote:
>> I understand the requirements, and the ICOM IC-7300 puts out 12.5W by 
>> default (can be adjusted via service menus).  I'm looking for a 
>> definitive answer as to the actual radiated power.  Like I said, the 
>> ICOM AH-4 tuner specifies its actual radiated antenna power but the 
>> KAT500 does not so that's why I'm asking.
>>
>>   Thanks and 73,
>>   Erik Tkal  -  W1QED
>>
>> On Nov 6, 2017, at 6:29 PM, Don Wilhelm <donwilh at embarqmail.com 
>> <mailto:donwilh at embarqmail.com>> wrote:
>>
>> Erik,
>>
>> The KAT500 relies on the transceiver power being reduced when tuning.
>> I am not certain how (or if) that happens with an Icom transceiver, 
>> but the KAT500 needs about 20 watts for reliable tuning.
>> That can happen automatically with the K3/K3S/KPA500 combination, but 
>> I don't know what the Icom can do to accommodate that same thing.
>>
>> 73,
>> Don W3FPR
>>
>> On 11/6/2017 5:35 PM, E T wrote:
>>> When tuning using a KAT500 from an ICOM via an AH-4 interface what 
>>> is the actual radiated power out the antenna?  I was reading that 
>>> ICOM's AH-4 tuner itself takes the input power and splits it into an 
>>> internal dummy load and only radiates something like 300mW out the 
>>> antenna, is the KAT500 comparable?
>>>
>>
>
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