Topics

output level

w2dxx
 

Hello all,

What has been your maximum measured RF output power for PEP on SSB and key down on CW for different levels of input drive?

Thank you.

Ron
W2DXX

Steve Bolia
 

Ron

I can get 1500W out on CW with somewhere between 50 - 60 watts on 10 - 160.
Don't do much SSB stuff and I don't have a PEP meter but it appear to be as
advertised (more than my Acom 1000!!!). Depends on what your attenuators
are set at in the Factory settings.


73

Steve, N8BJQ

-----Original Message-----
From: PrometheusDX2400@...
[mailto:PrometheusDX2400@...] On Behalf Of w2dxx
Sent: Sunday, November 07, 2010 8:26 PM
To: PrometheusDX2400@...
Subject: [PrometheusDX2400] output level

Hello all,

What has been your maximum measured RF output power for PEP on SSB and key
down on CW for different levels of input drive?

Thank you.

Ron
W2DXX



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

Yahoo! Groups Links

Marten Guthrie
 

Ron,
 
I get 1500 watts output with 50 watts drive, if I increase the drive I get an alarm as I recall.
 
73 de marten  ve2wu
 

----- Original Message -----
From: w2dxx
Sent: Sunday, November 07, 2010 8:26 PM
Subject: [PrometheusDX2400] output level

 

Hello all,

What has been your maximum measured RF output power for PEP on SSB and key down on CW for different levels of input drive?

Thank you.

Ron
W2DXX

Steven M. \(Mike\) dishop
 

Hi Ron,

I'm Mike, the main designer of the DX2400. Maximum power output depends on a
lot of things in a solid state amp, such as how close to 50 ohms resistive
impedance your antenna is. With that qualification, terminating the
amplifier into a 3KW Bird dummy load, I get 1500W out for 50 +/- 5W of
drive. Beyond 1500W output the drive increases. It takes the most drive on
21 MHz compared to any other band, and the least drive on 160m. The amp will
drive to >2KW output key down for less than 100W input on all bands. Beyond
90-95W of drive a protection circuit trips. Beyond 2200-2400W of output, a
protection circuit trips. There is only about 100W of difference if any
between PEP and Key down at 1500W out. I don't change the transceiver drive
when changing between CW and SSB. If you run ALC it won't matter anyway as
it will be clamped to 1500 out on every band and every mode.

The above statements are based on the linear power supply. If you get the
switcher there is no difference between PEP and key down, but you won't get
more than 2KW out anywhere as the switcher has less power than the linear
(5KVA vs 7KVA).

Operating your amp at legal limit, you will never have a problem with power
supply or heat. Steve and Marten run theirs heavy RTTY for multiple hours at
a time and don't have problems. I'm sure these gentlemen will tell you there
isn't anything on the market that can compete with this amp in terms of raw
power output and durability.

I hope this helps. Feel free to call me if you would like to discuss your
requirements further at 937 292 7981 or if you would like more photos,
brochures, etc. if you are contemplating a purchase. I'd like to add you to
the growing group of satisfied customers.

73,
Mike N8WFF

-----Original Message-----
From: PrometheusDX2400@...
[mailto:PrometheusDX2400@...] On Behalf Of w2dxx
Sent: Sunday, November 07, 2010 8:26 PM
To: PrometheusDX2400@...
Subject: [PrometheusDX2400] output level

Hello all,

What has been your maximum measured RF output power for PEP on SSB and key
down on CW for different levels of input drive?

Thank you.

Ron
W2DXX



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

Yahoo! Groups Links

w8nf <w8nf@...>
 

Mike, it's great to see an equipment designer actually responding on the group. You don't see that from the "big names"!

I interpreted the original question as one of when does gain compress. E.g. at what output power level, has gain dropped, for instance, by 1dB.

From your comments, it seems that 50watts input yields 1.5kW output (14.7dB gain), and maybe 90 watts input gives 2kW output (13.5dB gain), so at 2kW, the gain is compressed by 1.2dB. So, at 1dB compression, is it delivering on the order of 1.9kW?

By the way guys, if you have not seen Prometheus in person, you're missing out. Mike's had it running at Hamvention every year for the past many and it is an impressive demonstration of engineering.

73,

Dave W8NF

--- In PrometheusDX2400@..., "Steven M. (Mike) Dishop" <steven.dishop@...> wrote:

Hi Ron,

I'm Mike, the main designer of the DX2400. Maximum power output depends on a
lot of things in a solid state amp, such as how close to 50 ohms resistive
impedance your antenna is. With that qualification, terminating the
amplifier into a 3KW Bird dummy load, I get 1500W out for 50 +/- 5W of
drive. Beyond 1500W output the drive increases. It takes the most drive on
21 MHz compared to any other band, and the least drive on 160m. The amp will
drive to >2KW output key down for less than 100W input on all bands. Beyond
90-95W of drive a protection circuit trips. Beyond 2200-2400W of output, a
protection circuit trips. There is only about 100W of difference if any
between PEP and Key down at 1500W out. I don't change the transceiver drive
when changing between CW and SSB. If you run ALC it won't matter anyway as
it will be clamped to 1500 out on every band and every mode.

The above statements are based on the linear power supply. If you get the
switcher there is no difference between PEP and key down, but you won't get
more than 2KW out anywhere as the switcher has less power than the linear
(5KVA vs 7KVA).

Operating your amp at legal limit, you will never have a problem with power
supply or heat. Steve and Marten run theirs heavy RTTY for multiple hours at
a time and don't have problems. I'm sure these gentlemen will tell you there
isn't anything on the market that can compete with this amp in terms of raw
power output and durability.

I hope this helps. Feel free to call me if you would like to discuss your
requirements further at 937 292 7981 or if you would like more photos,
brochures, etc. if you are contemplating a purchase. I'd like to add you to
the growing group of satisfied customers.

73,
Mike N8WFF

-----Original Message-----
From: PrometheusDX2400@...
[mailto:PrometheusDX2400@...] On Behalf Of w2dxx
Sent: Sunday, November 07, 2010 8:26 PM
To: PrometheusDX2400@...
Subject: [PrometheusDX2400] output level

Hello all,

What has been your maximum measured RF output power for PEP on SSB and key
down on CW for different levels of input drive?

Thank you.

Ron
W2DXX



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

Yahoo! Groups Links

Steven M. \(Mike\) dishop
 

Dave,

Well, yes and no. The efficiency of the amplifier changes with frequency.
The efficiency vs. frequency curve looks like a shallow "V" that is skewed
to one side. The highest efficiency is hence on 160 and 80 meters,
decreasing then and bottoming on 15m, and then increasing on 10m. So, the
1dB compression point changes with frequency. This is due to several factors
mainly having to deal with the physical properties of the transistors and
ferrite components, but also having to do with the passband response of the
low pass filters. For example, the 15 meter filter is used on 17m as well.
Because of the filter ripple, 17m occurs on the high part of the pass band
ripple, and 15 m occurs on a decreasing part of pass band ripple. Hence
efficiency is higher on 17m than 15m.

So, if we take the worst case as 15m then we arrive at about 2KW for the 1dB
point. Recall safety kicks in for 90-95 watts of drive and it is already
putting out >2KW at that point. If we move to 17m we might find that the 1dB
compression point might occur with 2200W. If we go to 160 or 80m, where you
need power the most, the 1dB compression point probably moves up to close to
saturation at about 2400-2800W. Of course protection circuit takes the amp
offline well before this. I have seen about 3KW on 80m PEP with fast 30 WPM
dits into dummy load with protection bypassed in software and was afraid to
take it higher to actually find the limit. Transistors are expensive, even
for a manufacturer.

As to responding on the forum, I love to talk about this amp to anybody
anytime. It has been a labor of love and a dream of mine to have a legal
limit solid state brick on the key reliable amp since 1977 when I started
reading about high power transistors in QST. I've worked on a lot of
projects and teams in other industry over the years, but this is the first
time I can say something is all mine from concept to production. It helps in
a product when someone is passionate about their work and it usually shows.
I'm just happy that I can share my passion with those who are able to truly
appreciate it. This is why I personally handle every detail of the DX2400
from sales to service to insure that everyone who gets one is completely
satisfied. I think the members of the group will attest to their
satisfaction (I hope!) So to the group I thank each one of you because it is
you guys who enable me to make this all possible.

73,

Mike

-----Original Message-----
From: PrometheusDX2400@...
[mailto:PrometheusDX2400@...] On Behalf Of w8nf
Sent: Tuesday, November 09, 2010 11:41 AM
To: PrometheusDX2400@...
Subject: [PrometheusDX2400] Re: output level

Mike, it's great to see an equipment designer actually responding on the
group. You don't see that from the "big names"!

I interpreted the original question as one of when does gain compress. E.g.
at what output power level, has gain dropped, for instance, by 1dB.

From your comments, it seems that 50watts input yields 1.5kW output (14.7dB
gain), and maybe 90 watts input gives 2kW output (13.5dB gain), so at 2kW,
the gain is compressed by 1.2dB. So, at 1dB compression, is it delivering
on the order of 1.9kW?

By the way guys, if you have not seen Prometheus in person, you're missing
out. Mike's had it running at Hamvention every year for the past many and
it is an impressive demonstration of engineering.

73,

Dave W8NF

--- In PrometheusDX2400@..., "Steven M. (Mike) Dishop"
<steven.dishop@...> wrote:

Hi Ron,

I'm Mike, the main designer of the DX2400. Maximum power output depends on
a
lot of things in a solid state amp, such as how close to 50 ohms resistive
impedance your antenna is. With that qualification, terminating the
amplifier into a 3KW Bird dummy load, I get 1500W out for 50 +/- 5W of
drive. Beyond 1500W output the drive increases. It takes the most drive on
21 MHz compared to any other band, and the least drive on 160m. The amp
will
drive to >2KW output key down for less than 100W input on all bands.
Beyond
90-95W of drive a protection circuit trips. Beyond 2200-2400W of output, a
protection circuit trips. There is only about 100W of difference if any
between PEP and Key down at 1500W out. I don't change the transceiver
drive
when changing between CW and SSB. If you run ALC it won't matter anyway as
it will be clamped to 1500 out on every band and every mode.

The above statements are based on the linear power supply. If you get the
switcher there is no difference between PEP and key down, but you won't
get
more than 2KW out anywhere as the switcher has less power than the linear
(5KVA vs 7KVA).

Operating your amp at legal limit, you will never have a problem with
power
supply or heat. Steve and Marten run theirs heavy RTTY for multiple hours
at
a time and don't have problems. I'm sure these gentlemen will tell you
there
isn't anything on the market that can compete with this amp in terms of
raw
power output and durability.

I hope this helps. Feel free to call me if you would like to discuss your
requirements further at 937 292 7981 or if you would like more photos,
brochures, etc. if you are contemplating a purchase. I'd like to add you
to
the growing group of satisfied customers.

73,
Mike N8WFF

-----Original Message-----
From: PrometheusDX2400@...
[mailto:PrometheusDX2400@...] On Behalf Of w2dxx
Sent: Sunday, November 07, 2010 8:26 PM
To: PrometheusDX2400@...
Subject: [PrometheusDX2400] output level

Hello all,

What has been your maximum measured RF output power for PEP on SSB and key
down on CW for different levels of input drive?

Thank you.

Ron
W2DXX



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

Yahoo! Groups Links



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

Yahoo! Groups Links