by KD8MJR
Reviewed on Sun, 09/07/2014 - 00:40am KD8MJR Total Reviews: 1
Reviewer Rating
Construction Quality:
10
Masterpiece
Reliability:
9
Amazing
Performance:
9
Amazing
Looks:
9
Amazing
Ergonomics:
8
Great
Value For The Money:
10
Masterpiece
Customer Support:
8
Great
One Of The Best Amps I Have Ever Owned.
I purchased this Amp second hand in 2011 from another ham operator that had owned it for one year. I had always heard how THP made the best solid state amplifiers but it was not until I actually got one in my hands that I realized just how good THP amplifiers really are.
Construction:
The Amp is constructed to what I consider to be commercial grade standards. The Cabinet along with all the Knobs and Switches are all solid and give you the feeling that they will last a lifetime. The Exterior has an excellent finish but the paint while superb is applied fairly lightly to give the amp a nicer look but this also has a down side in that you really do not want to rest anything on top of it or you may scratch the finish. Inside the Amp is a joy to see, you open it up and your kind of mesmerized by how well everything is put together. THP spared no expense in the design and construction of this Amp. The interior parts are all perfectly placed and well secured, the wiring etc is done on a level that I have only seen in commercial equipment. The Transformer, Capacitors and other components are all top of the line.
Operation:
The Amp is rated at 750W using 4 x SD2933 Mosfets. What you get is really an amplifier with 1200W PA board that is only really limited by what the Transformer can deliver. It is very easy for this Amp to put out 850W and I have even seen it go to 1KW using my LP-100A meter. At 750W in SSB or CW you can use it for hours on end in a contest and the Fan will probably never switch into the high speed mode. In AM mode you will get the Fan to go into high speed in several minutes.Even though this model does not auto band change like some of it's more expensive siblings it's so easy to just turn the knob to the band you want and bingo it's ready to go. That brings up the subject of the much talked about THP protection circuitry which is IMO is absolutely lightning fast. The amplifier will Trip out if you have excessive SWR (above 1.8) or if the band switch is in the wrong position or if you have voltage fluctuations etc. The speed at which it trips out is so fast that my LP-100A which is inline with the keying jack cannot unkey the Amplifier faster than the Amp will trip out. That just goes to show you how fast it detects faults and reacts to them.
Final Verdict:
As you can imagine I am completely in love with this Amplifier! About my only complaint with it is that the Fan is a bit loud when it goes into high speed mode. Overall I highly recommend this Amp, you just can't go wrong with the 1.2Kfx, it performs like a pro, its very reliable, it looks fantastic and it has a very small footprint and is fairly light weight at 33lbs. If you can find one I would say Grab it in a second. Unfortunately I rarely see them come up for sale, most owners will just not part with them.
Specifications
Frequency: 1.8 — 28MHz all amateur bands including WARC bands Mode: SSB, CW, RITY
RF Drive: 85W typ. (75 —95W max.) Output Power: 750W PEP max., 630W CW (typ.)
Drain Voltage: 53V (when no RF drive)
Drain Current: 30A max. Input Impedance: 500 (unbalanced)
Output Impedance: 500 (unbalanced)
Final Transistor: SD2933 x 4 (MOS FET by ST micro)
Circuit Type: Class AB parallel push-pull
Cooling Method: Single Rear Fan Forced Air Cooling
Meter Output Power Range: 1kW Peak
Reflected Power: Pr 100W
Drain Voltage: Vd 60V Drain
Current: Id 50A Input/Output
Connectors: Type M-J (UHF SO-239)
AC Power: AC 230V (200/220/240V), 50/60Hz 7.5A max. AC 115V (100/110/120V), 50/60Hz 15A max.
AC Consumption: 1.35kVA max. when TX Dimension: 232 x 142 x 350 mm / 9.1 x 5.6 x 14.3 inches (WxHxD) Weight: Approx. 15kgs. or 33Lbs.
Positive points
Negative points
Excellent Construction quality both inside and out.
An unbelievably well built protection circuit that just about makes it bullet proof.
Uses an internal Linear Power Supply.
Small Footprint and fairly light weight for an amp with a Linear power supply inside.
Fan is fine at low speed but is a bit loud at high speed.
Like all Solid State Amps it does not like a lot of RF in the shack.
Your SWR must be 1.8 or below if your using this Amp.