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KY 196 voltage

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dbaleshta(at)tru.ca
Guest

Posted: Fri Apr 21, 2006 3:44 pm Post subject: KY 196 voltage

I have a King  KY 196 from another project (28v) and was hoping to use

it in my 12 volt project.  Is it at all possible to convert this w/o an

inverter, 2 batteries etc?  Searched the list and couldn't find

anything.  Any suggestions are appreciated.



Thanks

Doug

Lancair 360  - 50%

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gmcjetpilot(at)yahoo.com
Guest

Posted: Sat Apr 22, 2006 12:51 am Post subject: KY 196 voltage

Doug:

   

  Sorry no answer but went down that road, and my conclusion 

was a  28volt KY 196 (amps I think 10 amps) could not be 

economically or simply be used with a 12 volt plane. 

   

   

  The KY196's ARE cheap on the used market and that was my 

motivation. However I don't really need 16 watts transmit power 

in a little plane either. It came down to a DC-DC step-up converter. 

It was just cheaper and less weight to buy a 12 volt radio.

   

   

  If the radio had a 5 amp or less draw, fine a single converter 

would be tolerable, but 10 amps, that's a lot of juice! Check  

the spec, it's not low. It has over 2 times the transmit power 

of Coms that suck 6 amps, so I don't think I am off much.



   

  My post will no doubt raise a bunch of experts to prove me 

wrong. lol, I hope they do because I would buy a KY196 

on the cheap. An inverter is not cheap or light weight. 

   

  IMHO, sell it and buy a 12 volt and be done with it.

   

  Cheers George

   

   

   

  

 	  Quote: 	
		  From: "Doug Baleshta" <dbaleshta(at)tru.ca>



--> posted by: "Doug Baleshta" <dbaleshta(at)tru.ca>



I have a King  KY 196 from another project (28v) and was hoping to use

it in my 12 volt project.  Is it at all possible to convert this w/o an

inverter, 2 batteries etc?  Searched the list and couldn't find

anything.  Any suggestions are appreciated.



Thanks

Doug

Lancair 360  - 50%


	




		

---------------------------------

- The Matronics AeroElectric-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

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brian

Joined: 02 Jan 2006
Posts: 643
Location: Sacramento, California, USA

Posted: Sat Apr 22, 2006 6:33 am Post subject: KY 196 voltage

gmcjetpilot(at)yahoo.com wrote:



 	  Quote: 	
		     My post will no doubt raise a bunch of experts to prove me 

 wrong. lol, I hope they do because I would buy a KY196 

 on the cheap. An inverter is not cheap or light weight. 


	


I will rise to your bait George.



Given that all comm radios transmit AM and all of them use about the 

same technology, their power draw from the bus will be about the same 

for a given power output regardless of bus voltage. Most AM transmitters 

draw far less from the bus than the fuse-size specification calls for. I 

don't know of a single 6-8W transmitter that draws 6A from the 14V bus. 

Most require about 20W (I figure about 40% efficiency for an AM 

transmitter) and therefore will draw about 1.5A extra when transmitting 

(14V). (The radio circuitry burns something like 0.5A just idling.) So 

the total draw will be about 2A from the 14V bus at full transmit output.



A 16W radio is going to then need about 40W from the bus. Given that 

your DC-DC converter is going to be about 90% efficient, you are going 

to need about 45W from the bus at full output. That translates into a 

little over 3A at 14V. Throw in something to power the rest of the 

circuitry and then something for the wife and kids and your KY196 is 

going to really need about 4A from the 14V bus even after adding in for 

the converter.



And as for the mass of DC-DC converters, they are all switch-mode 

devices these days. They don't weight much at all and their 90% 

efficiency means they run pretty cool. Sure Power makes a 10A 14V-to-28V 

converter. That should solve the problem and you can probably get it for 

about $150. So if you can get a KY196 for $150 less than a KY197 you 

break even (except for the effort to install the extra box).



OTOH, once you install the converter you can think about using other 28V 

devices.



-- 

Brian Lloyd                         361 Catterline Way

brian-yak at lloyd dot com          Folsom, CA 95630

+1.916.367.2131 (voice)             +1.270.912.0788 (fax)



I fly because it releases my mind from the tyranny of petty things . . .

- Antoine de Saint-Exupery

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Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

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_________________
Brian Lloyd
brian-yak at lloyd dot com
+1.916.367.2131 (voice) +1.270.912.0788 (fax)

I fly because it releases my mind from the tyranny of petty things . . .
- Antoine de Saint-Exupery

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