Icom PW1 Solid State Kilowatt+
Tubeless, Knobless High-Tech Power House.

Bob Hutchinson, N5CNN

160M through 6M, Auto Tuner


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No tune, No knobs, No band change, No tuner knobs
Is this a boring amplifier or what? What is the operator to do? Icom's latest solid state jewel provides all. We received this amplifier for a short stay and short review.

I had enough time to photograph the outside and make a short run at our test bench to see if it lives up to it's reputation as a do all amplifier. Of course, if it is truly a do all amplifier, then I won't have much to do.

Cubic describes this black box. It is a cube, a square box weighing about 55 lbs. Damned unwieldy box too. Lotsa air openings, four cooling fans. Three small, one larger. Info from Icom web below:

  • Dimensions: 13.8 (W), 10.6 (H), 15.0 (D); 55 lb, 2 oz (approx.)
  • Auto band changing
  • Four antenna connectors
  • Built in auto antenna tuner
  • Capable of matching 3:1 SWR on HF, and 2.5:1 SWR on 6 meters
  • Matches a wide array of antennas
  • 4 cooling fans
  • 100% duty cycle (even during RTTY or SSTV)
  • Full break-in operation
  • Automatic AC input voltage selector
  • Dual CPUs for system operation, monitoring and control
  • CPU memories for automatic antenna selection and switching for fast band/antenna changes. Works with almost any make of HF, 6 Meter, or HF / 6M transceiver... not just ICOM rigs. Check with your dealer.


All female back side
Busy on the back. Four fans and 19 female connector things make it busy indeed. Two exciters can be connected and selected to four different antenna outputs. If the transceivers are capable (Icom), the 7 pin accessory  socket cable, included, can provide transceiver control of most functions. If the transceiver is older, a remote control cable can be used to switch bands.

Front side busy too.
The remotable control head can be used for complete manual control of functions. The metering system is extensive, including power out, voltage, current, SWR, ALC and temperature. Although this nice amplifier is broadband, with no tuning system, there are other manual functions such as manual push button control of the automatic antenna tuner, antenna selection and input selections.

The amplifier protection feature is complex, providing protection of the amplifier for excesses of temperature of FETs, power supply voltage, FET current or ALC control level. The protection circuit will also invoke when amplifier and exciter have a band mismatch, power supply has a malfunction, the FET gain drops or the power level among the four PA units becomes unbalanced or is not properly shared.

Automatic antenna tuner
The tuner will operate unaided or it can be manually provoked or turned off. The skimpy manual indicated that for 6 meters the tuner is manually operated or activated. I have not read about the limits or capacity of the tuner, other than the 3:1 SWR capability mentioned at the Icom web, but it is not a miracle tool, meaning it can't tune a coat hanger for 160 meter operation.

Frank Noble, W5HBO, who loaned us this fine amplifier for a quickie review, had conversed with a PW-1 owner that complain about the tuner not working on 160 meters. Further investigation revealed that the complainant was attempting to tune a 75 meter antenna to 160 meters. Well, this is possible with some expensive manual tuners that can handle a 50%, 5:1 SWR reflected power situation, but the PW-1 auto tuner can't handle that much reflected power so it just shuts down, tuner and amplifier. Although we couldn't test such, I suspect the tuner can handle a 3:1 SWR situation of about 25% reflected power just fine.

But, does it light up? Does it run?
We'll hook it up on the test bench and see if it will wreck itself trying to wreck our dummy load.
. . . . . . . .  TO BE CONTINUED

Just kidding -

Our test bench is equipped with a 2000+ watt fan cooled dummy load, wrecked by QRO Mark III and repaired, 3,500 watt low pass filter, Bird 43 and Coaxial Dynamics watt meters cabled in series, each with 2,500 watt slug for this test. The bench has a superb 7,500 w. antenna switch utilizing Jennings vacuum relays, designed and built by this writer for access to 75M & 40M dipoles, 20M, 17M and 15M verticals and the dummy load. Various putt-putt wattmeters are used between exciter and amplifier to measure drive power and SWR.

Accuracy of measurement
We use the average of the two wattmeters mentioned above. Both manufacturer's spec. an available inaccuracy of + or - 5% of slug rating at a mid-scale reading. This works out to be an error factor of + or - 125 watts at mid-scale. The maker's don't even mention accuracy at close to full meter right deflection. Remember, these wattmeters are the bottom of their line, most inexpensive of the manufacturer's offerings. See recent wattmeter article here.

CW Average Power Out, Watts

50W to 60W Drive
Power Out
1.950 Mhz 1,100W
3.925  Mhz 1,250W
7.245 Mhz 1,450W
14.250 Mhz 1,100W
18.140 Mhz 1.150W
21.350 Mhz 1,200W

Notes: No testing was done on 12 or 10 meter as the two bands were not yet enabled on this unit.

We did not have an exciter that was compatible with the PW-1 so we switched bands manually, Exciter drive was adjusted upward from a start of about 20 watts to the point where an increase provided no additional gain. Usually about 50 to 60 watts. A couple of attempts were made to over drive the amplifier, but the amplifier would not respond and, sometimes output power would actually be reduced. We were not using ALC.

We ran this amplifier hard, switching bands, switching from dummy load to antenna and back. Changing drive levels, tuner on, tuner off. Mismatching bands form exciter to amplifier. Suddenly increasing drive to 100 watts. Well, it is a do all amplifier and the designers knew we were coming. This knobless babe is bullet proof. Oh, boy, I do love Ham radio. If you work lotsa bands or love contesting, this quite point and shoot Icom broadband scattergun may be for you. Oh, by the way, price varies from about $4,695.00 to $4,699.00, depending on where you buy it.

Our thanks to W5HBO, Frank Noble for the loan of this amplifier.

Bob Hutchinson, N5CNN
President and Founder
Wireless Industry Association
713 467-0077

If you would like to publish an article here contact Bob Hutchinson, N5CNN.



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