Instruction manual

From March 2009 QST © ARRL
and SWR with the power disconnected. I
was surprised that it does not measure re-
flected power or display SWR in the PEP
mode. Power accuracy is very good, though
I did notice a jump up of a few watts when
switching from AVG to PEP in the key-down
CW test.
The large 3.75 × 3.25 inch meter face is
easy to read and provides good resolution
with tick marks every 0.5 W up to 20 W (mul-
tiply by 10 or 100 for higher power ranges).
A rear panel receptacle accepts 13.8 V dc
(power cord is included), and a meter lamp
switch is located on the rear panel.
I wished the case had more than its two
rubber feet. The front feet are smooth plastic
brackets that secure the front panel to the case
they prop up the front of the meter but pro-
vide no grip. Even with the meter’s weight,
the front end slides a little when switching
the RANGE or AVG/PEP toggle switches. A
couple of stick-on feet will fix that.
The 4 pages of instructions are in English
on one side and Japanese on the other. There
are plenty of illustrations and even some tech-
nical information on power measurement.
The CN-801 HP is a good choice for home
stations but a little large for mobile work.
Note that there are several other instruments
in the CN-801 family that cover different
frequency ranges and power levels.
US distributor: NCG Company, 15036
Sierra Bonita Ln, Chino, CA 91710; tel 909-
393-6133; www.cometantenna.com.
MFJ-870 GRANDMASTER
The MFJ-870 is the least expensive watt-
meter of this group. It’s the only one without
a cross needle meter, and the only one to use
passive circuitry for PEP readings. (MFJ
does offer a wide selection of other models,
some with cross needle meters.) This meter’s
frequency range is specified as 1.6 to 60 MHz
with forward power ranges of 30, 300 and
3000 W. It has a single meter movement with
a FUNCTION switch to choose FWD (forward
power), REV (reflected power), SWR SET
and SWR. To check SWR, switch to SWR
SET, adjust the SWR SET knob until the
meter needle hits the CAL mark, and switch
to SWR to read the value directly from the
SWR scale.
The 3.375 × 1.75 inch meter face is easy
to read and has scales for all three power
ranges. It has tick marks in 1/10/100 W
steps up to 10/100/1000 W, and in 2/20/
200 W steps from there to full scale. The
orange AVG/PEP pushbutton is hard to
miss, even in a dimly lit ham shack.
PEP circuitry is passive, so the rear panel
12 V dc receptacle is for the pale green
meter lamps only. A six foot power cord is
included. The black and charcoal gray metal
case is heavy but can move around the table
with its two rubber and two plastic feet.
Again, two extra stick-on feet would solve
this minor problem.
Although the meter needle responded
nicely to voice peaks, power accuracy varied
with power level and frequency. The meter
has two different SWR scales, LOW and
HIGH. The manual is not clear if the 300 W
range is considered low or high. A courteous
MFJ technician informed me that the HIGH
scale must be used for the 300 W range.
With the unit initially purchased, SWR
accuracy was poor, reading 1.3:1 across the
spectrum with our 2:1 resistive load. An-
other ’870 gave the same results. I contacted
MFJ about this, and after some checking
they discovered that an incorrect compo-
nent value was inserted on the production
line. MFJ supplied a corrected meter that
gave much closer readings, as shown in
the accompanying table. Customers with
units that have this problem should contact
MFJ for warranty repair at no charge. After
repair, the MFJ-870 is a useful meter at a
budget price.
Manufacturer: MFJ Enterprises, PO Box
494, Mississippi State, MS 39762, tel 800-
647-1800; www.mfjenterprises.com.
PALSTAR PM2000A
Palstar’s PM2000A is a cross needle watt-
meter specified to work from 1.8 to 60 MHz.
Like the Ameritron AWM-30, the PM2000A
has just two forward power ranges of 300 W
and 3 kW. Maximum forward power is speci-
fied at 2000 W.
The red pushbuttons select PEAK-HOLD,
PEAK/AVG, RANGE (300/3000 W) and
POWER on/off. A sturdy aluminum case
is finished in flat black. It blends in with
most radio gear, while the red pushbuttons
stood out in my monochromatic ham shack.
The attractive 2.5 × 1.75 inch backlit meter
face has tick marks at 5 W; in 10 W steps
from 10 to 200 W; and 25 W steps from
200 to 300 W. Multiply by 10 for the high
power range.
I was glad to see a wall mounted dc supply
included to run the active PEP circuitry and
meter lamps. Even better, a sturdy grounding
post and butterfly nut provide the PM2000A
with a station ground connection.
This is an active PEP reading meter and
Palstar has provided a PEAK-HOLD func-
tion that can be switched on and off. When
engaged, peak power measurement is held
for one second, providing enough time to
get a reading. (Other meters hold the peaks
during SSB transmission but this function
MFJ-870
Frequency range 1.6-60 MHz
Power range 1-3000 W
Power requirement 12 V dc (meter lamps only)
PEP measurement Passive
Size (height, width, depth) 3.25 × 7.5 × 4.5"
Price $100
Actual Power (W) Indicated Power (W)
Frequency (MHz) 2 14 28 50
5 W CW 4.9 5.5 5.5 5.5
5 W 50% 3.0 3.5 3.5 3.7
100 W CW 105 109 109 109
100 W 50% 83 95 95 97
100 W two-tone 88
1 kW CW 1140 1180 1180
1 kW 50% 1110 1130 1130
1 kW two-tone 1000
SWR Accuracy
1:1 SWR 1.1:1 1.0:1 1.0:1 1.3:1
2:1 SWR 2.3:1 2.3:1 2.3:1 3.0:1
Insertion loss (dB) <0.1 <0.1 <0.1 <0.1
– = Not measured.