First Impressions SPE Expert 1.3K - FA


First impressions of the SPE Expert 1.3K FA
(With built in Antenna tuner)


Having owned an Ameritron AL811, (had to keep it fed with cheap Chinese valves) then upgraded to a Yaesu Quadra VL-1000 (Nice amp) I soon discovered the short comings of this amp specific to my station, the Quadra it not easy to integrate its automatic features as is specifically designed for Yaesu radios, the Icom radio presented several compatibility issues. So I made the decision to upgrade again into something more modern and compatible with my Icom equipment.

In the DX fraternity the word SPE Expert kept coming up, along with this some negative reports of issues to be found on forums to do with power supply failures, I know that the kind of reporting without knowing the proper facts are to be taken with a grain of salt, however where there is smoke there is fire thus one proceeds with caution especially when pulling the pin on equipment worth several thousands of dollars.

A friend is involved in the commissioning of SPE Linear Amps (Not able to disclose further details) he has used these amps with many in service for a considerable time with no issues in reliability, a good recommendation I thought.

The technology used in the SPE Expert is a singular LDMOS device that comprises of two chips in the one package.
The amplifier integrates a Power Supply, Power Amp and Antenna Tuner, with a very well designed Micro Control system managing things in such a manner that one can set and forget.
This amplifier is rated at 1.3 KW, when tested into a dummy load easily made the stated power with as little as 10 Watts of drive. To produce the legal power, only 4 Watts of drive is required.

An antenna VSWR can be adjusted and saved into the tuner memory, this can be done for every antennas attached to the amp, the adjustment allows a whole band to be mapped for best VSWR and stored, this allows seamless operation from one band to other from one frequency to other with no need to retune the amp. The other feature is selecting a band via the radio, the antenna for that band is automatically selected by the amp, further one can program that band to have two antennas selectable from the amp key pad. Making antenna management very configurable and flexible.

The safety features include a very fast VSWR detector that turns off the amp in case of a fault, also shows the VSWR at the antenna and at the Amp providing an instant visual valuation of what is happening at the radiation end (BALUN)
Once this unit is programmed to your working conditions, its a set and forget situation.

The amp has two CAT channels with two RF inputs, this allows two radios to be connected to the amp.
The CAT system will accommodate the following brands:
The Icom IC-7610 I own, interfaced perfectly into this amp.

The power output is controlled in my opinion with the best ALC implementation set up I have found so far.
Testing the amp at full power 1.3 KWatts (Into Dummy Load) with the exciter power set at 100 Watts, the amp would reduce the drive to the optimum level that the amp required, this via the ALC, not many amps do this well, largely due to the non linear response when using different bands, The amp has lots of gain, I think this is the reason for the good loop control it exhibits.

I have tested with my spectrum analyzer at full power into a dummy load, the exciter power set to 100 Watts, allowing the ALC to control the power out at 1.3 KW, I could not detect any unwanted products, a reactive load test would have revealed any issues with the filter section of the amp, thus can't comment further only to say that on air tests at 400 Watts revealed no problems.

Power out put is selected in three steps, High, Med, and Low
To run legal power the low setting is selected requiring only 4 watts of drive, here one needs to be careful, because the amp is capable of 500 watts in the Low setting, the ALC control will only reduce drive if exceeding 500 Watts.

Overall this amp is the best I have used. the Yaesu Quadra antenna tuner was best as it used servo controlled tuning capacitors in a Pi configuration only selecting different values of L during the tune process, could tune just about anything.
The SPE Expert is not that forgiving it will not tune any antenna outside 3:1 VSWR
The protection system kicks in and stops you from tuning.
Not an issue if you use resonant antennas as the band edges should no be more that 3:1

Some of the negative reports on this amp in my opinion is reporting of faults created by bad operation, I note that there is advice out in the wild that to get best on air performance one should run an amps without ALC, I remember having an argument on air about this.
In fact the manufacturer stated that if using a radio that has to ALC control from an amp one can do so but must pay attention to insuring that the drive does not exceed 20 Watts.
What can happen with no ALC is two things;
a/ Overdrive and cause damage to the amplifier input circuit
b/ Create non linear product causing interference
So this popular advice is so wrong that I am horrified that its taking hold with some operators.
I wonder if this is also the reason behind some of the reported failures.

I find this amp after the initial set up very nice to use with good on air reports
The amp is available in two versions one with antenna tuner and one without, frankly with the provided flexibility of the antenna tuner in this amp I would not consider the no tuner option.

Powerful: 1.3kW PEP typ. (+/- 0.5dB)
Very Light: Less than 22 lbs. (10 kg.)
Very Small: height 4.72" x width 11.02" depth 14.17", connectors included.
Wide Frequency Coverage: 1.8Mhz to 54MHz, including WARC.
Internal Switching Power Supply with Power Factor Correction.
No jumper changes necessary to work from 100VAC to 255VAC.
Manages 4 antennas automatically.
Automatically switches between 2 transceivers.
S02R operation.
ATU Built-In: bypassable per antenna and band.
Up to 2 antennas can be selected for every band.
Additional receiving antenna can be selected.
Drives directly up to 4 dynamic antennas (StepplR, Ultrabeam) for an easiest layout.
No relay contacts are switched when current is flowing due to special software.
Fully remotable.
Remote control and all software upgrades fully available on SPE website.
USB and RS 232 ports.
MAX (1500W), MID(1000W) & LOW(500W).
Very clean and low distortion signal.
Both inputs always perfectly matched.
Quiet Operation: 4 fans linearly controlled by power supply and power amplifier temperatures.
Fully protected.
Fully Solid State: uses only one new, very rugged device.
Over 30,000 lines of software for performances that cannot be found together in any other amplifier.
Two very fast CPUs.
CAT and Band Data compatible with all rigs on the market allowing control of antennas, bands, ATU matching.
Available also without ATU, allowing significant savings.
Complete with heavy duty carrying bag, allowing carry-on to airplanes.
Certifications: CE, FCC.

73's de VK2ACR
Last edited: