Thanks, Bob - I had forgotten about being able to measure at the acc 12v
output. In any case, though, the front-panel display provides a pretty
good number. It says that the RX-only voltage at the K3 is 13.7 volts.
My worst-case at 100 watts key down is 12.6 - I don't know where the 11
volts came from. As someone suggested, it could be as simple as my
having plugged and unplugged the various powerpoles a few times.
But here's the real bottom line - depending on band, I only need at most
40 watts to drive my KPA-1500 to full output. At that level, voltage
only drops to 13.1, which is plenty good enough.
Thanks everyone for putting up with me - at least, I'm leaving this
exercise a little smarter than I went in...
73, Pete N4ZR
Check out the Reverse Beacon Network
at <http://reversebeacon.net>, now
spotting RTTY activity worldwide.
For spots, please use your favorite
"retail" DX cluster.
On 4/26/2020 12:32 PM, Bob McGraw K4TAX wrote:
Oh well, I need another cup of coffee. I'll try to do better proof
reading. Can't blame that one on auto-correct!
Cutting to the chase........., measure from the power supply POS
terminal to the ACC 12V on the K3 radio. That is the total voltage
drop in the POS DC path. Then do the same for the NEG terminal of the
power supply to the ground terminal on the radio. That is the voltage
drop on the NEG DC path. Add those two together and one has the total
voltage drop. Now, step by step, isolate where each amount of voltage
drop occurs.
Anytime over 0.5 volts total voltage drop occurs, something needs
attention. Thus DC Pos should be less than 0.25 volt drop and DC Neg
should be less than 0.25 volts. For a total of 0.5 volts drop at the
radio.
73
Bob, K4TAX
On 4/26/2020 11:22 AM, Adrian wrote:
I got a good chuckle out of that one Bob, happens to me often
take 2 >
The calculation is simple: E = I x R current multiplied by
resistance equals the voltage.
The calculation is simple: E = I x R current multiplied by
amps equal voltage.
73
Bob, K4TAX
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