[Elecraft] KAT500 assembly

[Phil Wheeler]

Hmm .. I thought I read that the KAT500 must be 
turned on before the K3. Is that old info?

Phil W7OX

On 6/6/14, 4:05 PM, Cady, Fred wrote:
> Don's suggestion of a 12 v relay is a good one but if you don't want to go that route, the rigrunner power pole distribution box with auto outlet turn on (http://www.westmountainradio.com/rigrunner.php) works well.  When you turn on the K3 it can turn on 10 other items.  I use it to turn on the KAT500, the P3, a KRC2, a W2 and probably other stuff I can't remember.
> Cheers,
> Fred KE7X
>
>
>
> -----Original Message-----
> From: Elecraft [mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Don Wilhelm
> Sent: Friday, June 06, 2014 4:50 PM
> To: GDanner; Mike Reublin; Slava Baytalskiy
> Cc: Elecraft List
> Subject: Re: [Elecraft] KAT500 assembly
>
> George,
>
> Yes, the current from the K3 12V output is limited to 500 ma. for older K3s and 1 amp in later K3s.  Older K3s can be upgraded with the Elecraft kit to provide 1 Amp capability.
>
> The KAT500 spec maximum draw is determined by how many relays are being activated by any particular antenna solution, so I would use the maximum value for the design point because you do not know which L/C combinations will be necessary for any particular antenna, and yes that maximum is greater than what the K2 12V output can supply (even with the upgrade).
>
> I would suggest that you power your KAT500 directly from your power supply rather than trying to use the K2 12 volt output.
>
> If you wish to use the K3 12 volt output so the power to the KAT100 (and other accessories) would be powered on when the K3 is turned on, I would suggest that you use the K3 12V output to drive a relay, whose contacts in turn provide power to those accessories (KAT500 included).
>
> Safety note - install fuses in each power cord (near the power source) with the fuse rated at 1.5 to 3 times the maximum expected current draw by that device.  In-line fuseholders can be obtained an auto parts store.  I prefer the ATC-3 blade type fuses, but YMMV.
>
> 73,
> Don W3FPR
> On 6/6/2014 4:07 PM, GDanner wrote:
>> My understanding is the KAT500 will overcurrent the K3 Aux DC output.
>> The KAT500 specification is 1.5A max (200 mA typ) from my IB (page 2
>> Rev B3 Nov 20, 2012. The 200 mA should be ok but the 1.5A is greater
>> than the K3 1 amp mod is rated for.
>>
>> I power my KAT500 from my station power supply. Therefore it comes on
>> prior to the K3; as required by the KAT500 IB (page 3 item 2 under
>> Elecraft K3 Transceiver and KPA500...).
>> Also see !IMPORTANT: note on the top of page 10 - "If you are using
>> the KAT500 with an Elecraft K3 transceiver connected using the DB15
>> cables as shown I Figure 1 or Figure 2, you must apply power to the
>> KAT500 before turning the K3 on.
>> 73
>> George
>> AI4VZ