| K6WL |
Rating:      |
2005-04-07 | |
| Superb Product |
Time Owned: 0 to 3 months. |
I recently won a bid on eBay for one of QRO's HF2500DX amplifiers. I was in the market for one and luck found me. I had been studying the market for some time prior and had since zeroed in on this amplifier. I wanted a quality amplifier with power and ruggedness "headroom" as well as hardware quality, and the selection was perfect. Rest assured it is NOT a medium quality amplifier at a high-quality price!
Upon receiving the amplifier from Ray Connin at QRO, I assembled it in less than one hour and had the filaments warming up. The pictures on the QRO website do the amp justice but until you get yourself into one, you do not appreciate the quality constuction and components used in Ray's amplifiers. After being in RF communications hardware engineering for decades and a ham for over 45 years, I can say it is top notch and will please even the pickiest of techies like myself.
The tune up procedure was real quick to pick up on and works just like the manual states. I was on the air in short order with my new amp and quite pleased with it. Also, the product manual that accompanies the amplifier is VERY WELL DONE and was a real joy to work through, from setup to operation.
Just a couple of comments -- this is not a small amplifier. You do need to make some space in your shack for it and make sure you have wired in solid 240VAC service for the amplifier.
Ray's attention to the deal and getting the amplifier tested and out to me was highly appreciated and very professional. It arrived WELL PACKED and in great shape even after surving several days of the UPS Gorilla Team. I can certainly recommend doing business with Ray and QRO for your amplifier needs. |
|
| AA4H |
Rating:      |
2005-02-05 | |
| Great amp and company. |
Time Owned: 0 to 3 months. |
I purchased the QRO HF-2500DX a few months ago in the fall of 2004; I have only used it a few times on any band except 160 meters. The amp is a solid performer, with an easy 1500 watts output with 40 to 50 watts drive. When I purchased the QRO, my friend Lonnie W4FXO was telling me “it is the best amp available” now I'm sure he is correct. He sure has been happy with his. Naturally, he was my first contact on 20 meter SSB just to see how it played. Lonnie gave it a great report and he sure sounded fine here on his.
When I first received the QRO, I tried it on 20 meters and it loaded fine but when I tried to load it on the bottom end of 160 meters the open frame change-over relay welded closed. After two phone calls and two e-mails to QRO, Ray told me to send the chassis back to him; which I did immediately. He replaced the open frame relay and installed a vacuum relay, the QSK feature (which I had not purchased), added a turn to the tank coil to enhance the 160 meter operation, at no cost to me and turned it around in one day. He really went beyond the call of duty in my estimation to insure that I was a happy customer. And since the amp was a Christmas present from my XYL; he got it back to me a day or two before Christmas so I could open it on time. The service I received from Ray Connin was exceptional. Service like that is almost unheard of this day-and-time.
On 160 meters where I do most of my operating; 40 watts of drive is over one KW out and 50 watts of drive is 1500 watts out. The amp is built like an armored tank. I think this is one of the best built amplifiers on the market. If you are looking for a legal limit amplifier, take a good look at the QRO HF-2500DX. With the two 4CX800A’s this amp just loafs along at full legal limit. Depending on the band; 30 to 50 watts drive provides full legal limit output.
To fully appreciate the design and construction of this amp, you have to take a look inside. The Peter Dahl plate transformer accounts for much of the weight of this amp. It weighs about 41 pounds. Total weight is about 90 pounds so you will need a sturdy operating position to set it on. I rebuilt my operating desk while Ray was building my amp.
I recommend this amp to anyone who wants a key-down legal limit amp.
|
|
| WB3AYW |
Rating:      |
2004-11-13 | |
| Great amp |
Time Owned: more than 12 months. |
The Amp was as advertized for output ect.
Have had amp for 3 years with no problems!
Contacted factory to lower output with ALC for Kenwood TS870s at max. and parts was forwarded free. Great amp. |
|
| NL7G |
Rating:      |
2004-09-29 | |
| Thumbs UP QRO |
Time Owned: 6 to 12 months. |
Although I purchase the QRO2500DX a few months ago, I have only used it a few times until the 2004 CQ WW RTTY contest. Part of the reason was that I have a second story ham shack and have had to fight the TVI problems. Therefore I normally use a brand X amplifier at the 1/3 power to reduce the interferce.
Well for the contest, I used the QRO at 1500W output with NO TVI and was quite surprised. It handled the full duty requirements of FSK hour after hour with ease. The low drive from my FT1000MP gave me ease of mind there as well. The
Amplifier ran reasonable cool for the power output,
so I was not in a sweet box during the contest.
I am really pleased with my QRO. Thanks Ray |
|
| KA3YRT |
Rating:      |
2004-05-22 | |
| Excellent Amplifier |
Time Owned: 6 to 12 months. |
If you are looking for a high end legal limit amplifier, be sure to take a good look at the QRO HF-2500DX. With the two 4CX800A tetrodes this amp just loafs along at full legal limit. Depending on the band, 20 to 40 watts drive provides full legal limit output.
To really appreciate the design and construction of this amp, you have to take a look inside. Overkill comes to mind. The two Peter Dahl transformers account for much of the weight of this amp. It comes in at about 90 pounds total. So you will need something sturdy to set it on.
When I first got the amplifier, I immediately encountered a problem. It was not getting full output power. As it turned out, one of the tubes had gone south. Since this problem was immediate, I’m assuming it may have had some rough handling during shipping. This problem is hardly worth mentioning, but the service I received from Ray Connin was exceptional. When I called QRO, I talked with Ray, the owner of the company. He had me ship the chassis back so he could check it out. One week later it was back on my doorstep and ready to roll. That kind of service is almost unheard of anymore.
I expect this amplifier will outlast me. But if I ever had the need for a second amp, I would definitely GO-QRO
|
|
| WV9G |
Rating:      |
2004-04-27 | |
| Sweet Amp! |
Time Owned: 0 to 3 months. |
| This amp is built to withstand a bomb blast, puts out amazing power with little exciter input, and I plan to keep my cold bony fingers holding onto it even after I go to the grave! It dwarfs my Dentron MT-3000A tuner, my Icom 765 Pro2 and my Astron VS-50M power supply. I'm glad now that I built a new heavy-duty desk/counter to put all this on. Shipped very well, extra screws and fuses, excellent quality throughout, super workmanship and design, phenominal power. Well worth the money and the wait to have it built for me. Now I wish there was a higher number to assign to it because it should be rated well above a 5.0! |
|
| KP2L |
Rating:      |
2004-02-22 | |
| The "Hummer" of HF amps! |
Time Owned: more than 12 months. |
I bought this amp new in March 2000.I am very please with it. It's built like a high quality overbuilt tank, and puts out a big signal for me, a real "pile up buster".
Recently I had it back to Ray at QRO for a repair & upgrade. The service was quick. Ray upgraded two of the boards in my amp. The price for labor and parts was VERY resonable, almost downright cheap. QRO stands behind their product with good service. These amps are not inexpensive, but as a lifetime investment are well worth the money. When you get your hands on one you won't want to ever let go of it !!! |
|
| W5BEN |
Rating:      |
2003-12-06 | |
| Super HF Amp |
Time Owned: 6 to 12 months. |
It has been nearly a year now that I have owned the QRO 2500DX amp. It has performed flawlessly. I have not had to call Ray at the factory again for any reason.
Once in a while, when I goof, the protection circuitry response is immediate, taking the amp off-line as advertised. And the great thing is that the reset is just easy as pushing the yellow button back in.
I recommend this amp without hesitation to anyone who wants a key-down legal limit amp.
----------------------
Earlier 5-star review posted by W5BEN on 2003-01-31
I bought this amplifier used. I had a bit of a problem with it blowing a fuse in the cathode circuit which may have been due to arcing in the antenna system due to snow. The support from Ray at QRO Technolgies was superb. Replaced the fuse with a SloBlo and no further problems.
The amp puts out 1500 solid watts measured with a Bird Thruline meter. The required drive is less than 35 watts on all bands. It is one heavy-duty amp. I would rate it much better than the Ten-Tec Titan I previously owned.
One word of caution: I bought this amp from Burghardt in Watertown, SD. When Ray suggested that the fuses might be blowing due to internal arcing in a tube or tubes, I wrote sales at Burghardt 3 separate emails asking if their warranty would cover the tubes. They have never answered any of my emails. Buying from them is easy, but get your warranty IN WRITING before you send money. |
|
| W3IZ |
Rating:      |
2003-11-30 | |
| Solid Performer |
Time Owned: more than 12 months. |
I have had my QRO HF-2500DX amp for about 4 years now and it performs flawlessly. As others had stated it is one heavy son-of-a-gun and it just loafs along at 1500 watts with 20 - 30 watts drive depending on the band you're on. I use it mostly for SSB & RTTY with my FT-1000MP and always get excellent reports and a number of first in catagory contest certificates. No problem bust pile up or creating one with this amp. I shopped around all the others, Alpha, Commander, Ameritron, etc. but the main reason I bought this amp was because of Ray Connin, the owner of the company. He was patient in answering all of my e-mails and phone calls. After all, I want to be sure that when I spent $3k I was sure about it. This is the last amp I will ever need. It tunes smoothly and quickly and I can QSY in about 45 seconds which is quick enough for my operating style. Quiet, dependable, rock solid station accessory from a reputable manufacturer. Highly reccommended.
*****
Norm, W3IZ |
|
| K0SF |
Rating:      |
2003-01-03 | |
| Power and Reliability in One Package |
Time Owned: more than 12 months. |
I have owned my HF2500DX for 4 years. It has been through contests, pile-ups, MARS nets, and casual operating. It has also seen wrong antenna selections, mis-tunes, over-drive, as well as a warm and humid basement !
Having used many amplifiers and amateur gear, I will go out and say that this is the best designed piece of gear I have owned. Why ?
- Function: Full 1.5 KW CW output, 160m - 10m. Many amps claim as much but don't deliver; the HF-2500DX does it !
- Robust: The Alpha 99 and 91B are near equivalents to the HF2500DX. Yet, the weight difference is dramatic: The QRO HF2500DX is nearly 50% heavier than the 99 (90 vs 65 lbs) due to a heavier plate transformer. I have not quantified the difference, but I am sure the KVA of the QRO is greater, and that's what you want for a stiff supply.
- Ease of use: Once the amplifier settings are noted (I use a spreadsheet), the settings are repeatable, and not especially critical. There is no need to re-tune this amp once the settings are known.
- Noise: Quietest amplifier I have ever used. I note that the exhaust air is warm (not hot) in the slow fan position, even while contesting.
- Reliable: I have had only two problems:
1.) Loose bandswitch knob: Problem went away after re-tightening.
2.) Blown fuse. Replaced and didn't happen again (fuses weaken over time).
Cost: Approximately $600 cheaper than the Alpha 99, yet as I mentioned above, the QRO power supply is larger. Yes, the Alpha has power metering and QSK is standard, but I'd rather have the bigger power supply.
That's it. I have had to get inside all other amplifiers (Alpha, Henry, Collins, Heathkit) many times to repair. QRO stands alone. It is the Maytag of amateur amplifiers !
One last comment regarding grid driven amps: I am sensitive to the need of maintaining low IMD. One of the big advantages of a high gain (20 dB) amplifier grid driven amp (QRO HF2500, Alpha 99, Collins 30S1) over the cathode driven (typ only 10 - 13 dB gain) is that the drive power is much reduced. IMD is cumulative: Once your exciter has generated it, the amplifier will only add more. Therefore, if you limit the drive from the exciter to 25 watts (instead of 100w in the case of the cathode driven), the overall IMD produced is much less. IMD typically tracks output power by a factor of two. For example, a 6 dB reduction in drive from the exciter will reduce IMD by 12 dB).
I have always respected Rich Measures (AG6K) opinions on amps. He has said that the Heathkit SB-220 amplfier provided the best value of any amp designed (cost vs. function and reliability). I agree with him as it applies to the then legal limit of 1 KW DC input. For today's 1.5 KW output limit, and the need for 160 - 10m operation, I will assert that the QRO is the best amplifier value on the market today. |
|