New Wattmeter Talk - hamradioworkbench.com
Transcript of New Wattmeter Talk - hamradioworkbench.com
![Page 1: New Wattmeter Talk - hamradioworkbench.com](https://reader030.fdocuments.us/reader030/viewer/2022012808/61be0d69c6e7e259d40dc144/html5/thumbnails/1.jpg)
HF
Wattmeter
Talk
Doug Millar
K6JEY
JEY Labs Presents
![Page 2: New Wattmeter Talk - hamradioworkbench.com](https://reader030.fdocuments.us/reader030/viewer/2022012808/61be0d69c6e7e259d40dc144/html5/thumbnails/2.jpg)
Purpose
▪Highlight interesting meters and their
design.
▪What each offers that is special.
▪What their limitations are.
![Page 3: New Wattmeter Talk - hamradioworkbench.com](https://reader030.fdocuments.us/reader030/viewer/2022012808/61be0d69c6e7e259d40dc144/html5/thumbnails/3.jpg)
Terms
▪Accuracy factors-
▪ K is the coupler‘s accuracy and linearity
M is the meter’s accuracy and linearity
▪5% of full scale vs 5% of reading.
▪Three types of scales
▪Digital (linear)
▪Analogue- Linear and E2/r = W
![Page 4: New Wattmeter Talk - hamradioworkbench.com](https://reader030.fdocuments.us/reader030/viewer/2022012808/61be0d69c6e7e259d40dc144/html5/thumbnails/4.jpg)
Wattmeter Scale▪Watt meters read power as a voltage. Using E²/r =W
produces a scale with ¼ power at mid range. This scaling
helps compensate for the 5% ofs accuracy problem at low
power. Some meters use a linear power scale.
![Page 5: New Wattmeter Talk - hamradioworkbench.com](https://reader030.fdocuments.us/reader030/viewer/2022012808/61be0d69c6e7e259d40dc144/html5/thumbnails/5.jpg)
General Comments
▪Meter scale resolution indicates meter and
coupler possible accuracy
▪Most cross needle meters lack resolution
▪Few have excellent movements
▪In high RF environments, use analog
meters. SWR can get into a digital meter.
▪Load to meter line length and condition can
effect SWR and power measurement
▪ Use low loss cable.
![Page 6: New Wattmeter Talk - hamradioworkbench.com](https://reader030.fdocuments.us/reader030/viewer/2022012808/61be0d69c6e7e259d40dc144/html5/thumbnails/6.jpg)
Types of Meters
▪Termaline Capacitive voltage divider
▪ Directional Couplers
▪Inductive couplers
▪Thermocouple meters
▪Calorimeters
![Page 7: New Wattmeter Talk - hamradioworkbench.com](https://reader030.fdocuments.us/reader030/viewer/2022012808/61be0d69c6e7e259d40dc144/html5/thumbnails/7.jpg)
Termaline
▪Sensors are a capacitive voltage
divider and have a broader frequency
response than the regular inductive
elements. At higher power all the
elements seem to have a flatter
frequency response.
![Page 8: New Wattmeter Talk - hamradioworkbench.com](https://reader030.fdocuments.us/reader030/viewer/2022012808/61be0d69c6e7e259d40dc144/html5/thumbnails/8.jpg)
Termaline Schematic
The capacitive
voltage divider *coupled to the line
is much more
broad banded than
an inductive loop.
*
![Page 9: New Wattmeter Talk - hamradioworkbench.com](https://reader030.fdocuments.us/reader030/viewer/2022012808/61be0d69c6e7e259d40dc144/html5/thumbnails/9.jpg)
Bird 6154 25-1296MHZ
My go to meter
Fs. 5,15,50,150w
![Page 10: New Wattmeter Talk - hamradioworkbench.com](https://reader030.fdocuments.us/reader030/viewer/2022012808/61be0d69c6e7e259d40dc144/html5/thumbnails/10.jpg)
Terminating Watt Meters
Micro Match 621u 4W
0-500MHz 5% OFS
Bird 6258 30W
Add attenuators for greater range
Load Resistor plus voltage divider
.0-1,000 MHz 10% OFS
![Page 11: New Wattmeter Talk - hamradioworkbench.com](https://reader030.fdocuments.us/reader030/viewer/2022012808/61be0d69c6e7e259d40dc144/html5/thumbnails/11.jpg)
Bird 43 and others
use an Inductive loop and
are directional
(17-20db isolation)
![Page 12: New Wattmeter Talk - hamradioworkbench.com](https://reader030.fdocuments.us/reader030/viewer/2022012808/61be0d69c6e7e259d40dc144/html5/thumbnails/12.jpg)
Bird 4410a Meter
3 elements give you
21 ranges in power and
3 ranges in frequency
5% of READING accuracy.
Uses a battery.
All you will need.
![Page 13: New Wattmeter Talk - hamradioworkbench.com](https://reader030.fdocuments.us/reader030/viewer/2022012808/61be0d69c6e7e259d40dc144/html5/thumbnails/13.jpg)
Good and the Bad- loop coupler
▪17-20db directional isolation
▪The lower the power the narrower the
passband
▪Higher power is more broadband.
▪Wide power range in power ability
▪Correcting for M and K factors difficult
▪Bird 4410 uses temp compensated bridge.
▪Significantly broadens measurement range
▪Stability increased.
![Page 14: New Wattmeter Talk - hamradioworkbench.com](https://reader030.fdocuments.us/reader030/viewer/2022012808/61be0d69c6e7e259d40dc144/html5/thumbnails/14.jpg)
Inductive Coupler Type
▪Most HF couplers are “inductive”
▪Accuracy can be very good
▪Component quality is critical
▪Layout and isolation are also critical
![Page 15: New Wattmeter Talk - hamradioworkbench.com](https://reader030.fdocuments.us/reader030/viewer/2022012808/61be0d69c6e7e259d40dc144/html5/thumbnails/15.jpg)
MFJ 894
▪ Typical lower priced meter
▪ Better than average cross needle meter
▪ Good power ranges
▪ Accuracy just in spec
▪ Recalibrated to 5% ofs
![Page 16: New Wattmeter Talk - hamradioworkbench.com](https://reader030.fdocuments.us/reader030/viewer/2022012808/61be0d69c6e7e259d40dc144/html5/thumbnails/16.jpg)
Kenwood SW 2000
SWC 3 HF 1500w CW
![Page 17: New Wattmeter Talk - hamradioworkbench.com](https://reader030.fdocuments.us/reader030/viewer/2022012808/61be0d69c6e7e259d40dc144/html5/thumbnails/17.jpg)
Yaesu YS 60
Reflected power can effect readings
Internal coupler
![Page 18: New Wattmeter Talk - hamradioworkbench.com](https://reader030.fdocuments.us/reader030/viewer/2022012808/61be0d69c6e7e259d40dc144/html5/thumbnails/18.jpg)
Drake W-4
The W-4
manual tells you
How to calibrate it to
5% of Reading.
Remote coupler.
Unique among all
The meters.
![Page 19: New Wattmeter Talk - hamradioworkbench.com](https://reader030.fdocuments.us/reader030/viewer/2022012808/61be0d69c6e7e259d40dc144/html5/thumbnails/19.jpg)
Mirage MP-1
5% accuracy
Excellent meter
Separate coupler
Requires 9v.
Easy to cal. <5%
All freq. ok.
![Page 20: New Wattmeter Talk - hamradioworkbench.com](https://reader030.fdocuments.us/reader030/viewer/2022012808/61be0d69c6e7e259d40dc144/html5/thumbnails/20.jpg)
Elecraft HF Coupler
.5db accuracy (5%)
Goes with P3 or W2
![Page 21: New Wattmeter Talk - hamradioworkbench.com](https://reader030.fdocuments.us/reader030/viewer/2022012808/61be0d69c6e7e259d40dc144/html5/thumbnails/21.jpg)
Collins 302C-1
with Brune coupler
![Page 22: New Wattmeter Talk - hamradioworkbench.com](https://reader030.fdocuments.us/reader030/viewer/2022012808/61be0d69c6e7e259d40dc144/html5/thumbnails/22.jpg)
Collins Meter Schematic by Brune
![Page 23: New Wattmeter Talk - hamradioworkbench.com](https://reader030.fdocuments.us/reader030/viewer/2022012808/61be0d69c6e7e259d40dc144/html5/thumbnails/23.jpg)
Brune Inside
Rigid construction
Feed through caps
Excellent shielding
First rate
Piston Trimmers
(quartz)
Type N connectors
(No loose parts)
![Page 24: New Wattmeter Talk - hamradioworkbench.com](https://reader030.fdocuments.us/reader030/viewer/2022012808/61be0d69c6e7e259d40dc144/html5/thumbnails/24.jpg)
Autek WM-1
Auto SWR
5% ofs
Still made
Remote coupler
![Page 25: New Wattmeter Talk - hamradioworkbench.com](https://reader030.fdocuments.us/reader030/viewer/2022012808/61be0d69c6e7e259d40dc144/html5/thumbnails/25.jpg)
Heath HM 102
Clever and accurate
Remote coupler
Power measurement is not directional
![Page 26: New Wattmeter Talk - hamradioworkbench.com](https://reader030.fdocuments.us/reader030/viewer/2022012808/61be0d69c6e7e259d40dc144/html5/thumbnails/26.jpg)
Thermocouple Meter
▪Very broad frequency range
▪Wide power range and up to 1w
without attenuators.
▪AC/DC transfer ability for calibration.
▪Relatively slow responding
▪PRD, HP, and Anritsu
![Page 27: New Wattmeter Talk - hamradioworkbench.com](https://reader030.fdocuments.us/reader030/viewer/2022012808/61be0d69c6e7e259d40dc144/html5/thumbnails/27.jpg)
Anritsu ML4803a/ MA4601a
Dc-5GHz, 200MW, cheap
Make sure you get a cable!!
Add attenuators to read higher power
30db=100w
![Page 28: New Wattmeter Talk - hamradioworkbench.com](https://reader030.fdocuments.us/reader030/viewer/2022012808/61be0d69c6e7e259d40dc144/html5/thumbnails/28.jpg)
Calorimetric Meters
▪HP 434 and Bird 6091
▪Both use a fluid to absorb the input
power and as a heat transfer medium.
▪Very low SWR and excellent accuracy
2% or better.
▪Can be very slow.
▪ From mill watts to Megawatts.
![Page 29: New Wattmeter Talk - hamradioworkbench.com](https://reader030.fdocuments.us/reader030/viewer/2022012808/61be0d69c6e7e259d40dc144/html5/thumbnails/29.jpg)
Bird 6091
![Page 30: New Wattmeter Talk - hamradioworkbench.com](https://reader030.fdocuments.us/reader030/viewer/2022012808/61be0d69c6e7e259d40dc144/html5/thumbnails/30.jpg)
Bird 6091 Calorimeter
DC to 2.5GHz 2%
10 to 200W
Uses water
for transfer
![Page 31: New Wattmeter Talk - hamradioworkbench.com](https://reader030.fdocuments.us/reader030/viewer/2022012808/61be0d69c6e7e259d40dc144/html5/thumbnails/31.jpg)
HP434A One of the best. Make sure you get the oil
with it.
![Page 32: New Wattmeter Talk - hamradioworkbench.com](https://reader030.fdocuments.us/reader030/viewer/2022012808/61be0d69c6e7e259d40dc144/html5/thumbnails/32.jpg)
PRD 680
Calorimeter
Thermocouple Type
.01mw to 1w
DC to 1GHz
![Page 33: New Wattmeter Talk - hamradioworkbench.com](https://reader030.fdocuments.us/reader030/viewer/2022012808/61be0d69c6e7e259d40dc144/html5/thumbnails/33.jpg)
Over the Top Meters
▪Rhode and Schwartz NAP meter
Dual display
AC/Battery
Multiple ranges with
available sensors.
5% of reading
accuracy
Outstanding coupler
Expensive
![Page 34: New Wattmeter Talk - hamradioworkbench.com](https://reader030.fdocuments.us/reader030/viewer/2022012808/61be0d69c6e7e259d40dc144/html5/thumbnails/34.jpg)
LP100A
Highly accurate
Versatile
First rate coupler
And
Digital “back end”
5% of reading
Accuracy
$500
![Page 35: New Wattmeter Talk - hamradioworkbench.com](https://reader030.fdocuments.us/reader030/viewer/2022012808/61be0d69c6e7e259d40dc144/html5/thumbnails/35.jpg)
Recalibrating Notes
▪If you are sure yours is off.
▪Get a meter that is known to be better
▪Check it at three levels of power
▪Check it at three frequencies. 3.7, 14 and
28MHz
▪Write down your data
▪Check it in both directions
▪Suggested calibration meter- Bird 4410, LP
100A
![Page 36: New Wattmeter Talk - hamradioworkbench.com](https://reader030.fdocuments.us/reader030/viewer/2022012808/61be0d69c6e7e259d40dc144/html5/thumbnails/36.jpg)
Conclusion-Even with a new meter, check
the calibration. Check the setup.
▪Look at coupler design and quality of components.
▪Look at meter scale resolution.
▪Go for accuracy and convenience
▪Connection RF cables between load and meter can drastically effect accuracy.
![Page 37: New Wattmeter Talk - hamradioworkbench.com](https://reader030.fdocuments.us/reader030/viewer/2022012808/61be0d69c6e7e259d40dc144/html5/thumbnails/37.jpg)
Best Bang for the Buck?
▪Drake W-4
▪Accurate 5% of reading
▪Sturdy, no battery
▪Easy to read
▪Separate coupler
▪Bird 6154
▪Accurate over full range
▪Made for rough usage
▪Versatile
![Page 38: New Wattmeter Talk - hamradioworkbench.com](https://reader030.fdocuments.us/reader030/viewer/2022012808/61be0d69c6e7e259d40dc144/html5/thumbnails/38.jpg)
That’s the Round-up
▪I hope it has been informative and
interesting
▪Feel free to contact me.
![Page 39: New Wattmeter Talk - hamradioworkbench.com](https://reader030.fdocuments.us/reader030/viewer/2022012808/61be0d69c6e7e259d40dc144/html5/thumbnails/39.jpg)
Thank you
▪UHF wattmeter talk-
▪Google K6jey wattmeter talk.