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K Line Power Requirements

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Jack

K Line Power Requirements

Thanks to Ron, Dick, Phil, Don and Jack responses. Very helpful!!

RE: Specifications

1. Specifications. All came from the manuals!

2. Jack noted that the KPA500 manual shows "100 to 125 VAC or 200 to
250 VAC, 50/60 Hz, approx. 1000 VA"

3. I calculated the current by dividing the VA by the VAC. I get 8.3 A
for 120 VAC and 4.13 for 240VAC.

Are my calculations correct?

If so, then what is the relationship to the "PA Current 20 A maximum" and
the "PA Voltage 60 VDC nominal" as shown in the manual

RE: The K3PA500 does not run off the 13.8 VDC power supply

1. The K3PA500 does not run of the 13.8 VDC power supply but in my
shack there is only one 120 VAC circuit so the current
drawn by the K3 and the KPA500 have to be added together if I was to run the
amp with the supplied 120 VAC power cord.

2. Because of this limitation and the admonition to not run the amp
and rig on the same circuit I ran 240 to my shack to power
my Ameritron AL-811H. This was a completely independent circuit. I ran my
K3, Yaesu UHF/VH and amp (at 600 to 800 Watts) with no problems.
BTW, when I ran the 240 to the shack I was able to then add a ground to the
old, 1933, two wire 120 VAC circuit!

3. I am planning on running my KPA500 at 240 but wanted to calculate
the current draw on the house 120 circuit since that is the supplied
cable connection!

In conclusion, I think a 25 amp supply would be more than adequate. I am
leaning towards an Astron RS-35M. I like the absence of fans!!!

I would like a smaller, lighter supply and would consider a switching
supply. I will check the archives for recommendations but if anyone has an
immediate
recommendation I would appreciate it!

Jack AE6GC

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Jack

K Line Power Requirements

The specifications according to the manuals are:

K3 20.0 A (recommended) 3-4 (typical) NOTE:
When barefoot I run 100 Watts for CW, SSB and RTTY

P3 00 .5 A

KPA500 20.0 A

FT-7800 00.5 A RCV
NOTE: 6M, 2M, 440. Squelched. I sometimes have this on scan when working HF.

08.5 A XMT NOTE: I
do not think I have ever transmitted on both at the same time.

Do I really need a 49.5 amp continuous output PS?

I have an ASTRON RS-70M that has been running for 10 years with no problems.
I was hoping to get a smaller, lighter supply to help simplify my setup.
This is one of the reasons I am thinking of the KPA500, in spite of its high
price.

One alternative I am considering is the MFJ-4245M.

Any advice and/or suggestions would be appreciated!

Jack AE6GC

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Bruce Beford-2

Re: K Line Power Requirements

The KPA500 runs off the shack's AC service, not the DC supply. Don't know
where you got that 20A figure. Do not figure the KPA500 into your DC
requirements.
73,
Bruce, N1RX

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Grant Youngman

Re: K Line Power Requirements

In reply to this post by Jack

The KPA-500 is AC input. It does not run on 13.8vdc.

A 25A peak supply is fine for what you've listed.

Grant/Nq5t

Sent from my iPhone

On Aug 5, 2011, at 4:18 PM, "Jack Regan" <[hidden email]> wrote:

> The specifications according to the manuals are:
>
>
>
> K3 20.0 A (recommended) 3-4 (typical) NOTE:
> When barefoot I run 100 Watts for CW, SSB and RTTY
>
> P3 00 .5 A
>
> KPA500 20.0 A
>
>
>
> FT-7800 00.5 A RCV
> NOTE: 6M, 2M, 440. Squelched. I sometimes have this on scan when working HF.
>
>
> 08.5 A XMT NOTE: I
> do not think I have ever transmitted on both at the same time.
>
>
>
> Do I really need a 49.5 amp continuous output PS?
>
> I

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Don Wilhelm-4

Re: K Line Power Requirements

In reply to this post by Jack

Jack,

The KPA500 power comes from the AC receptacle, not a 13.8 volt power
supply, so take 20 amps off that total. And since you do not transmit
on both the FT-7800 and the K3 at the same time, you do not have to add
the 8.5 amps.
As I sum the maximum required currents that will be drawn at any one
time, 21 amps will suffice.

On 8/5/2011 5:18 PM, Jack Regan wrote:

> The specifications according to the manuals are:
>
> K3 20.0 A (recommended) 3-4 (typical) NOTE:
> When barefoot I run 100 Watts for CW, SSB and RTTY
> P3 00 .5 A
> KPA500 20.0 A
> FT-7800 00.5 A RCV
> NOTE: 6M, 2M, 440. Squelched. I sometimes have this on scan when working HF.
> 08.5 A XMT NOTE: I
> do not think I have ever transmitted on both at the same time.
>
> Do I really need a 49.5 amp continuous output PS?
>
> I have an ASTRON RS-70M that has been running for 10 years with no problems.
> I was hoping to get a smaller, lighter supply to help simplify my setup.
> This is one of the reasons I am thinking of the KPA500, in spite of its high
> price.
> One alternative I am considering is the MFJ-4245M.
>
>

Dick Dievendorff

Re: K Line Power Requirements

In reply to this post by Jack

I use an Astron 70A linear supply for two K3s for SO2R and all my other 12V
station equipment. I wanted to be able to transmit concurrently on both
radios in case I decided to enter a multi-single or multi-two contest. If I
were alone and never keyed two transmitters concurrently, a single 30- or
35A supply would fulfill all my 2 radio needs.

The KPA500 has its own internal AC (linear) power supply, it needs 20A at
120VAC, and is not connected to your station +12V power supply.

73 de Dick, K6KR

-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of Jack Regan
Sent: Friday, August 05, 2011 2:18 PM
To: [hidden email]
Subject: [Elecraft] K Line Power Requirements

The specifications according to the manuals are:

K3 20.0 A (recommended) 3-4 (typical) NOTE:
When barefoot I run 100 Watts for CW, SSB and RTTY

P3 00 .5 A

KPA500 20.0 A

FT-7800 00.5 A RCV
NOTE: 6M, 2M, 440. Squelched. I sometimes have this on scan when working HF.

08.5 A XMT NOTE: I
do not think I have ever transmitted on both at the same time.

Do I really need a 49.5 amp continuous output PS?

I have an ASTRON RS-70M that has been running for 10 years with no problems.
I was hoping to get a smaller, lighter supply to help simplify my setup.
This is one of the reasons I am thinking of the KPA500, in spite of its high
price.

One alternative I am considering is the MFJ-4245M.

Any advice and/or suggestions would be appreciated!

Jack AE6GC

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AC7AC

Re: K Line Power Requirements

In reply to this post by Don Wilhelm-4

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