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| Reviews Summary for Commander VHF-1200 |
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Reviews: 7
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Average rating: 5.0/5
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MSRP: $2395.
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Description: 50 MHz monoband amplifier based on a single 3CX800A7 Eimac ceramic metal triode, capable of 1200W PEP SSB, 700W continuous carrier output.
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More info: http://www.command1.com/vhf1200.asp
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write your own review of the Commander VHF-1200.
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K6AER
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Rating: 5/5
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Jun 5, 2007 16:01
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Great bang for the buck amplifier
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Time owned: 0 to 3 months
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Bought the amplifier used from a friend in Washington and he shipped with the transformer separated. Each box was 45 lbs. and everything arrived intact. I placed the transformer in the amplifier with 4 ea. ¼ 20 bolts. You have to remove the top and bottom covers to place the transformer. Fifteen little Allen 6/32 screws have to be removed. The transformer connects with a single Molex connector. If you’re not sufficiently strong you might have some help lifting the transformer in place. The space is compact and the transformer does not have a lifting handle.
The amplifier was built in 1996 and I would say the condition was about a 9.7 on a ten scale. The silver plated coil was tarnished but cleaned up with a little polish the rest of the cabinet was cleaned with a spurt of 409 and a cotton cloth.
Wiring and component quality is first rate with almost everything being easy to get to. The input circuitry and capacitor bank in the bottom cooling plenum are a bit harder to get to for servicing. The input tuning can be accessed via an opening on the rear and you can adjust the input VSWR via a trimmer capacitor. Along with the manual was a test sheet showing the harmonics being down at least 60 dBc. The amplifier has a separate low pass filter placed after the Pi-L network.
Amplifier keying is about 44 mA at 12 VDC. This is a ground to key function with a operate/standby switch on the front. You will need 240 VAC, 20 amps to realize the full output potential of this amplifier. I do not recommend running this amplifier on 120 VAC. Input and output RF connections are SO-239’s
Operation is very straight forward. Tune for max output with 20 watts while increasing the drive until about 45-50 mA grid current is achieved. Maximum output and plate dip are the same. The load capacitor is a 6:1 reduction and very smooth. The tune is a multi turn plunger capacitor and is very broad in tuning. This amplifier is a tune to set and leave it alone. If you over drive the amplifier, the grid will trip at 70 mills. Reset the Grid trip by cycling the operate/standby switch. The rated output is 1200 watts but I found it will do an easy 1500 watts out with 50 mA grid drive. The power supply is the same one as used on the Commander HF-2500 and I might add the high voltage only drops 100 volts at full output from the metered 2200 VDC.
On the air the audio quality is the same as the IC-756 Pro III and at full output no one could find any splatter. Using the amp make a big difference in six meter operation. This amp does not have QSK and on CW you need to use our transceiver in the Semi break in mode. The amplifier T/R relay will get your attention.
Metering is Grid current on the left and Plate Voltage/Plate Current switchable on the right meter. Upon power application the meters are bottom lit. After a two minute warm up the green operate LED will glow. The key LED is red upon keying but only when the operate/standby switch in the operate position and after the two minute warm up.
The T/R relay is a loud click but the rest of the amplifier is very quite with the cooling fan noise at about 52 dBa noise level at two feet from the front. Tube exhaust is out the top with air being drawn from the sides and bottom. You cannot butt this amplifier up against other equipment. You need two inches of free space on top and sides so it can breath.
I have used the amplifier for about two weeks and it is a pleasure to own and operate. Two minute warm up and you are ready to go. I called Pat Stein the owner at Command Technologies and he is shipping out a current manual. Nice guy and easy to get a hold of if you have questions.
This is my first Command Technologies amplifier and while it lacks the sophistication of the Alpha and ACOM amplifiers is a good investment and solidly built. I would recommend this amplifier to anyone.
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VE2JKA
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Rating: 5/5
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Jan 12, 2007 20:32
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Jusk Kick A!!!!
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Time owned: more than 12 months
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Incredible! I love this amp... Max I got out of it on FM was 750W and ssb it will give you 1kw + no problem..smooth tuning, heats up a little at max output yet it cools off quite rapidly. Owned it for a little over a year now and it has performed flawlessly every time.
Highly recommended.
ve2jka
radioquebec.net
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KC9AWS
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Rating: 5/5
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Sep 7, 2002 04:40
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5/5
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Time owned: 0 to 3 months
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Pat Stein is very helpful and accomadating when he sells you this amp. The amp is well made and works very well. It's simple to operate and the manual is easy to understand. Pat called me the next day after my Email and answered all my questions up front. This amp is the ULTIMATE AMATEUR RADIO TOY. Reports from 150 miles away, ground waves, raise my signal by 4 on their s meter. The fan noise is real low.
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NH7RO
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Rating: 5/5
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Jun 28, 2002 23:25
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Excellent amp--recommended!
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Time owned: 6 to 12 months
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The Commander is an excellent 6M amp in all respects that I recommend it to anyone serious about magic band dxing. I'm currently driving mine with less than 20 watts PEP from a SSB LT6S transverter which results in around 600 watts PEP output. Conveniently running it off 117 volt house current works fine at these levels, too. At some point in the future I plan to drive it with an FTV-1000 for full output which will require me re-wiring it for 220v (very easy to change via terminal-strip jumpers). The first time I fired up the amp I worked stations in FJ, 9Y, KP4 and PY during a rare and marginal opening to the Caribbean from my mid-Pacific qth. It would have not been possible to make and complete these contacts without the solid help of the Commander VHF-1200. The amp has made a good number of European long-path openings bear fruit for me as well. My hat is off to Pat Stein for building such a reliable and easy-to-use amp that never needs retuning (I'm always in the weak-signal portion of the band)and delivers clean power. The slightly noisy blower fan doesn't particularly bother me--it's obviously needed to keep things running cool and dependable. My philosophy is like what the T-shirt often seen at hamfests proclaims, "Life is too short for QRP!" I'm glad I invested in this fine piece of gear and I now look forward to the upcoming fall F2 season more than ever before.
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KC4PX
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Rating: 5/5
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Jun 28, 2002 15:22
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Excellent 6 Meter amp
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Time owned: 3 to 6 months
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Once you tune this amplifier, you never have to touch it... I purchased this used - built in 1999. This is the older version of the VHF-1200 with the older TUNE control (i.e. 17 turns from min to max), so it takes a bit to get it tuned the first time. After that, don't touch.
I've always received excellent audio reports with 900-1200 PEP out, driven with my IC-756Pro + Heil and W2IHY EQ. Excellent also for contests and high duty cycles. I do recommend this amp to any serious 6 Meter DXer.
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WD8OST
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Rating: 5/5
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Jul 18, 2001 11:40
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great
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Time owned: more than 12 months
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n4cpm, said it all-have had mine since feb. 1998 works flawless it is best 6m 1200 watt. if you do not want to play games this is for you--mike
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N4CPM
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Rating: 5/5
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Aug 28, 2000 23:17
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Strong & Sturdy
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Time owned: more than 12 months
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The Commander VHF-1200 is a 6 meter amp. I have had mine for over a year and it has been service free. Like most Commander Amps the only negative I can say is that the fan is a little noisy. The amp performs great. I get 1200 watts from 60 watts drive and can even push it to 1500 watts with 70 watts input. The 3CX800A7 Ceramic Metal Triod really takes a licking and it keeps on ticking. Tune up is easy and you really never need to tune again as long as you stay in the CW or SSB part of six meters, great bandwith. Although 1200+ watts is a bit much on 6 meters, this Amp is a good investment if you gona chase grids and work a new country. I have worked over 350 grids and 25 countries with mine. 73 Ed
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