On Dec 8, 12:25*pm, Jim Higgins wrote:
On Sun, 5 Dec 2010 21:28:56 +0000 (UTC), No Spam
wrote:

Another idea I just had is perhaps having someone with a ceramics oven
paint on the endcaps with ceramic glaze. It would look like a giant
ceramic resistor! *But then again, I would guess that as the resistor
heated up, it would crack. * Never mind...

I'd guess the high heat used to fire ceramics would simply cause the
carbon to burn up.

In the Navy, the shipyards all have a device called a Load Bank. It's
a
large metal tank on an insulated vehicle. The tank is filled up with
salt water and electrodes lowered into it to test the output of the
ship's
generators. Any chance that it has ham applications? I intend to try
it
first with an antenna analyzer and then, if it looks promising, my rig.

On Dec 9, 12:42*am, "Sal M. Onella" wrote:
On Dec 8, 12:25*pm, Jim Higgins wrote:

On Sun, 5 Dec 2010 21:28:56 +0000 (UTC), No Spam
wrote:

Another idea I just had is perhaps having someone with a ceramics oven
paint on the endcaps with ceramic glaze. It would look like a giant
ceramic resistor! *But then again, I would guess that as the resistor
heated up, it would crack. * Never mind...

I'd guess the high heat used to fire ceramics would simply cause the
carbon to burn up.

In the Navy, the shipyards all have a device called a Load Bank. *It's
a
large metal tank on an insulated vehicle. The tank is filled up with
salt water and electrodes lowered into it to test the output of the
ship's
generators. *Any chance that it has ham applications? *I intend to try
it
first with an antenna analyzer and then, if it looks promising, my rig.

Yes they did the same with transmitters, often all you need was a
metal mop bucket and a piece of copper pipe.

Jimmie

On 12/9/2010 7:56 AM, JIMMIE wrote:
On Dec 9, 12:42 am, "Sal M. wrote:
On Dec 8, 12:25 pm, Jim wrote:

On Sun, 5 Dec 2010 21:28:56 +0000 (UTC), No
wrote:

Another idea I just had is perhaps having someone with a ceramics oven
paint on the endcaps with ceramic glaze. It would look like a giant
ceramic resistor! But then again, I would guess that as the resistor
heated up, it would crack. Never mind...

I'd guess the high heat used to fire ceramics would simply cause the
carbon to burn up.

In the Navy, the shipyards all have a device called a Load Bank. It's
a
large metal tank on an insulated vehicle. The tank is filled up with
salt water and electrodes lowered into it to test the output of the
ship's
generators. Any chance that it has ham applications? I intend to try
it
first with an antenna analyzer and then, if it looks promising, my rig.

Yes they did the same with transmitters, often all you need was a
metal mop bucket and a piece of copper pipe
Jimmie

A water load bank is good for hundreds of KW at 60hz.

For use with a pair of 6146's we used to wire a lamp to a coax
connector. We had a load as well as visual indication of the relative
power output.

On Dec 9, 1:51*pm, Jim wrote:
On 12/9/2010 7:56 AM, JIMMIE wrote:





On Dec 9, 12:42 am, "Sal M. *wrote:
On Dec 8, 12:25 pm, Jim *wrote:

On Sun, 5 Dec 2010 21:28:56 +0000 (UTC), No
wrote:

Another idea I just had is perhaps having someone with a ceramics oven
paint on the endcaps with ceramic glaze. It would look like a giant
ceramic resistor! *But then again, I would guess that as the resistor
heated up, it would crack. * Never mind...

I'd guess the high heat used to fire ceramics would simply cause the
carbon to burn up.

In the Navy, the shipyards all have a device called a Load Bank. *It's
a
large metal tank on an insulated vehicle. The tank is filled up with
salt water and electrodes lowered into it to test the output of the
ship's
generators. *Any chance that it has ham applications? *I intend to try
it
first with an antenna analyzer and then, if it looks promising, my rig..

Yes they did the same with transmitters, often all you need was a
metal mop bucket and a piece of copper pipe
Jimmie

A water load bank is good for hundreds of KW at 60hz.

For use with a pair of 6146's we used to wire a lamp to a coax
connector. We had a load as well as visual indication of the relative
power output.- Hide quoted text -

- Show quoted text -

I built a wattmeter of sorts around a circuit like that. After tuning
up the transmitter to light bulb dummy load I would measure the
resistnace of a photo resistor exposed to the light then see how much
60Hz AC voltage and current took to light the lamps to the same
brillance.

Jimmie

Yes they did the same with transmitters, often all you need was a
metal mop bucket and a piece of copper pipe
Jimmie

A water load bank is good for hundreds of KW at 60hz.

For use with a pair of 6146's we used to wire a lamp to a coax
connector. We had a load as well as visual indication of the relative
power output.- Hide quoted text -

- Show quoted text -

I built a wattmeter of sorts around a circuit like that. After tuning
up the transmitter to light bulb dummy load I would measure the
resistnace of a photo resistor exposed to the light then see how much
60Hz AC voltage and current took to light the lamps to the same
brillance.

Jimmie

if you were really good you could estimate the power from the brightness
in real time. it did take a lot of practice.

On Thu, 9 Dec 2010 19:21:48 -0800 (PST), JIMMIE
wrote:

I built a wattmeter of sorts around a circuit like that. After tuning
up the transmitter to light bulb dummy load I would measure the
resistnace of a photo resistor exposed to the light then see how much
60Hz AC voltage and current took to light the lamps to the same
brillance.

Hi Jimmie,

An excellent example of the concept of a transfer standard. This
method is one of the oldest and most robust methods of accurate
measurement. It removes a lot of variables (by, ironically, not
changing them) that would be exceedingly difficult to determine their
impact upon an accurate measurement.

73's
Richard Clark, KB7QHC

In message , Richard Clark
writes
On Thu, 9 Dec 2010 19:21:48 -0800 (PST), JIMMIE
wrote:

I built a wattmeter of sorts around a circuit like that. After tuning
up the transmitter to light bulb dummy load I would measure the
resistnace of a photo resistor exposed to the light then see how much
60Hz AC voltage and current took to light the lamps to the same
brillance.

Hi Jimmie,

An excellent example of the concept of a transfer standard. This
method is one of the oldest and most robust methods of accurate
measurement. It removes a lot of variables (by, ironically, not
changing them) that would be exceedingly difficult to determine their
impact upon an accurate measurement.

Do a Google on "Grease Spot Photometer" (back to school physics, over 50
years ago!). Very simple to make, and pretty accurate.
--
Ian

On Fri, 10 Dec 2010 19:52:55 +0000, Ian Jackson
wrote:

Do a Google on "Grease Spot Photometer" (back to school physics, over 50
years ago!). Very simple to make, and pretty accurate.

Hi Ian,

A very good suggestion which immediately led me to:
http://www.phy6.org/outreach/edu/greaspot.htm

A variation of this that I calibrated in the lab is an Optical
Pyrometer:
http://www.pyrometer.com/Pyro_Optical.html

Comparison measurements can be very accurate iff what you are
comparing to (aka standard) is known to sufficient accuracy. Both
references provide more than enough to inform the reader with the
essential details.

Slightly more elaborate methods of measuring RF power fall into the
Calorimetric method (actual heat). Hewlett Packard made the ultimate
heat transfer standard - the HP 434A power meter DC to 12GHz!

73's
Richard Clark, KB7QHC