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Hans Summers April 8th 04 01:10 PM


"PaoloC" wrote in message
...
Richard wrote:

Does anyone have a ny designs for a (low) power meter that would read

powers
of up to 1w (down to say 50mw or even lower) up to and inc. 6m?


Check this out:
http://www.webx.dk/oz2cpu/radios/miliwatt.htm

It is based on Analog Devices' AD8307 chip. You can skip the PIC part if
you have a reliable DVM!

A nice chip the AD8307, very easy to use. I used one as the logarithmic
amplifier stage in my spectrum analyser. It's available at Farnell
http://www.farnell.com in 8-pin DIL, which is another nice thing for a
relatively new IC. Expensive though, and of all the chips I could've fried
when constructing my analyser, I had to fry that most expensive one and get
a replacement. I guess to do otherwise would probably be in violation of
Murphy's law, or Sod's law or someone's.

73 de Hans G0UPL
http://www.HansSummers.com




[email protected] April 8th 04 06:01 PM

"Richard" writes:
Does anyone have any designs for a (low) power meter that would read powers
of up to 1w (down to say 50mw or even lower) up to and inc. 6m?


I don't know what your intended use is, but if you just want to measure
output power while testing a transmitter, what about just measuring the
voltage across your dummy load, since, for the same resistor, power is
proportional to voltage squared? (It may take a bit of work/ingenuity
to measure RF voltage at six meters, but that's one of the things that
being a ham is all about.)

--Myron, W0PBV.
--
Five boxes preserve our freedoms: soap, ballot, witness, jury, and cartridge
PhD EE (retired). "Barbershop" tenor. CDL(PTXS). W0PBV. (785) 539-4448
NRA Life Member and Certified Instructor (Home Firearm Safety, Rifle, Pistol)

[email protected] April 8th 04 06:01 PM

"Richard" writes:
Does anyone have any designs for a (low) power meter that would read powers
of up to 1w (down to say 50mw or even lower) up to and inc. 6m?


I don't know what your intended use is, but if you just want to measure
output power while testing a transmitter, what about just measuring the
voltage across your dummy load, since, for the same resistor, power is
proportional to voltage squared? (It may take a bit of work/ingenuity
to measure RF voltage at six meters, but that's one of the things that
being a ham is all about.)

--Myron, W0PBV.
--
Five boxes preserve our freedoms: soap, ballot, witness, jury, and cartridge
PhD EE (retired). "Barbershop" tenor. CDL(PTXS). W0PBV. (785) 539-4448
NRA Life Member and Certified Instructor (Home Firearm Safety, Rifle, Pistol)

Richard Heindel April 8th 04 09:58 PM


"Richard" wrote in message ...
Does anyone have any designs for a (low) power meter that would read powers
of up to 1w (down to say 50mw or even lower) up to and inc. 6m?

Rgds
Richard SO5GB

Oak Hills Research Has a real nice little meter, http://www.ohr.com/wattmeter.htm

Richard WB8KRN



Richard Heindel April 8th 04 09:58 PM


"Richard" wrote in message ...
Does anyone have any designs for a (low) power meter that would read powers
of up to 1w (down to say 50mw or even lower) up to and inc. 6m?

Rgds
Richard SO5GB

Oak Hills Research Has a real nice little meter, http://www.ohr.com/wattmeter.htm

Richard WB8KRN



Lou April 8th 04 10:31 PM

I have a schematic of a device I built for testing and servicing. While mine
isn't designed to read in watts or milliwatts, it does detect the smallest
amount of RF . There is a pot on it to adjust sensitivity. I'm sure it could
be adapted somehow for your needs. Knowing my repairs and such, I'm going to
say 3-5 watts pegs the meter. So, as I said, you can scale it back or design
the thing to work for you. Cost is about $10 IF you have to buy any thing.
It can be made from junk box parts and a spare case from a scrapped piece of
equipment or housing from the shack - or just about anything. If
interested, e-mail me for info.

Lou

--
Clearing out shop, shack and house. I have a list of things for sale.
NOS/New/Used, Parts, radio accessories, etc. All are AS IS. Interested?
E-Mail me.

"Richard Heindel" wrote in message
...

"Richard" wrote in message

...
Does anyone have any designs for a (low) power meter that would read

powers
of up to 1w (down to say 50mw or even lower) up to and inc. 6m?

Rgds
Richard SO5GB

Oak Hills Research Has a real nice little meter,

http://www.ohr.com/wattmeter.htm

Richard WB8KRN





Lou April 8th 04 10:31 PM

I have a schematic of a device I built for testing and servicing. While mine
isn't designed to read in watts or milliwatts, it does detect the smallest
amount of RF . There is a pot on it to adjust sensitivity. I'm sure it could
be adapted somehow for your needs. Knowing my repairs and such, I'm going to
say 3-5 watts pegs the meter. So, as I said, you can scale it back or design
the thing to work for you. Cost is about $10 IF you have to buy any thing.
It can be made from junk box parts and a spare case from a scrapped piece of
equipment or housing from the shack - or just about anything. If
interested, e-mail me for info.

Lou

--
Clearing out shop, shack and house. I have a list of things for sale.
NOS/New/Used, Parts, radio accessories, etc. All are AS IS. Interested?
E-Mail me.

"Richard Heindel" wrote in message
...

"Richard" wrote in message

...
Does anyone have any designs for a (low) power meter that would read

powers
of up to 1w (down to say 50mw or even lower) up to and inc. 6m?

Rgds
Richard SO5GB

Oak Hills Research Has a real nice little meter,

http://www.ohr.com/wattmeter.htm

Richard WB8KRN






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