There's no way 40W drives exactly 1500W on all bands. Here's what I get
into a DL (no tuner). Power measurements based on the LP100 which was
calibrated by Larry last year - not what I would call a current cal but
certainly better than a generic Bird. Feed with a key-down in CW, with
the data taken after about 5 seconds to get a stable reading. Dont'
take the values as gospel. There is at least a 50w error range.
160 1644W
80 1466W
40 1515W
20 1436W
15 1371W
10 1414W
But it's definitely unrealistic to assume that the amp should have a
uniform gain vs. frequency response. The gain is going to be related to
many things.
There is a LPF hanging off the back and it's insertion loss is a factor
- and it's going to drift a touch as it heats up. Theres the front end
which likly a pad. The overall gain is be in compliance with the FCC
regulation. Most SS amps native gain is such that a few watts is enough
to get LL output levels and I'm sure that's the case with the LDMOS even
if they have a ton of NFB in the design. Plus the effects of the
combiners internally which are definitely not going to be completely
flat. And there is some compression that gets to be easily measurable
once you hit about the KW level. And temp. And who knows what else.
73/jeff/ac0c
alpha-charlie-zero-charlie
www.ac0c.com
On 15-Aug-18 10:18 PM, Paul Baldock wrote:
Are you saying it took exactly 40W input on each band to produce 1500W
out..
I find the gain of the amp very different from band to band. For
example on 80M mine takes 32W to produce 1500W into a dummy load, and
15M it takes 47W to produce 1500W in to a dummy load. That's a
variation of 1.7dB, not very flat.
Also as others have reported as the amp warms up the gain decreases a
little (requires a bit more drive).
- Paul KW7Y
At 07:40 PM 8/15/2018, you wrote:
Just curious what other users of the KPA-1500 see as the efficiency
reported by the KPA-1500 utility app.
The following efficiencies are being report by my KPA-1500 utility
app by band into a dummy load running 40 watts input and 1500 watts
output:
80M CW: 61%
80M SSB: 64%
40M CW: 54%
40M SSB: 59%
20M CW: 52%
20M SSB: 52%
17M CW: 55%
15M CW: 64%
15M SSB: 62%
12M CW: 68%
10M CW: 56%
10M SSB: 58%
Does this compare favorably with other KPA-1500 owners?
Charles K5UA
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net
This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to p...@paulbaldock.com
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net
This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to keepwalking...@ac0c.com
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net
This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com
