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Reviews For: Dentron DTR-1200 L

Category: Amplifiers: RF Power - HF & HF+6M

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Review Summary For : Dentron DTR-1200 L
Reviews: 9MSRP: 455.95
Description:
HF (80-10 Meter) AMplifier
Product is not in production
More Info: http://
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
1594.8
WA6JBD Rating: 2023-03-13
A rarity? Time Owned: more than 12 months.
What little information that exists online about the DTR-1200L says it's rare. I don't know how many were produced, but they don't show up on the used market very often. Mine came from eBay, purchased to get by while a new amplifier ordered was on long back order.

On arrival, I opened it up for inspection. I'd suggest you always do that before powering up older tube equipment for the first time, especially amplifiers. The fan was binding from worn out bearings, so a replacement was ordered before I powered it up.

Operationally, I've noticed input VSWR is a bit high, on the order of 2:1 or higher. Using the IC-7300's built-in tuner allowed for higher power for less drive power. I was able to get about 400 watts out with about 60 watts drive. Seems a bit low, I purchased some NOS 572Bs on eBay. I now see more like 600 watts. 10 DB gain...

Since the new amplifier arrived, this was removed from service for a year or so, and recently put back in service for use with the Collins S-Line station recently assembled. This is where the DTR-1200L shines!

The higher input VSWR isn't a problem with a tube-type transmitter, so after amplifier tuning, I touch up the exciter tuning a touch. I see about 700 watts PEP out when driven with the 32S-3 transmitter and excellent reports.

I don't know how rare they really are, but I never hear another on the air. I think it's a gem of an amplifier, so if you ever get a chance to get one, run, don't walk to grab it before someone else does.
KC0GA Rating: 2015-05-20
Decent, cheap amp Time Owned: more than 12 months.
Bought one of these new from AES in Milwaukee back in ’81 to replace the used GLA1000 I had been using. Appreciated the quieter fan and relay, and the higher power. The “vernier” style Tune knob made tune-up quick and easy. Front panel switch for rear accessory sockets was potentially very handy. It already had tuned input for solid state xcvrs (unlike the GLA), and after sending proof of licensure got back a small pc board to mount on the band switch for 10 meter operation (unmarked on the front panel).

Power transformer came in a separate package. Good thing too, as the amp never would have survived shipment with it mounted. The mounting bolts were not included, and the chassis compartment for it was very cramped, making installation difficult. Once installed, the weight of the transformer distorted the chassis so that the top cover screw holes didn’t line up. Stripped a couple of the very small screws in the process. Grrr!

I thought the manual had serious omissions. No information or instructions about the advertised continuous duty operation (reduce power? key down time? drop a brick on it à la Alpha? I don’t think so).

No explanation of “OHC” light; best guess—Over Heat Condition. Which would be a good thing to have as I don’t think many other amps had one. No explanation of operation with xcvrs which do not provide ALC interconnect with amp. No explanation of tube handling in “unpacking” or “installation” sections (some tubes don’t like finger prints). No information on wiring of accessory sockets even on schematic. No info on bulb replacement or fuse requirements for 220VAC operation.

That said, the amp performed well for around the 15 years I had it in three different QTH’s. Ran a lot of traffic with it on the old IMRA net, and logged Palmer Station Antarctica (KC4AAC) on 20 meter sideband with 1200 watts input. Replaced the 572B’s once after they went soft. The tubes were mounted sideways and stacked one over the other, but never had any trouble with sagging elements or shorts. Despite the initial frustration, all in all it was affordable, it worked well, and I was glad to have it.
W1MBB Rating: 2010-09-29
SOLID as a rock! Time Owned: 0 to 3 months.
Amps are not built like this any more. Simple grounded grid design, pair of 572B give about 600w out. Tuned input, ALC, very functional mulimeter, compact desktop package. Only issue is heat, which can be easily solved with inceased air flow.

Solid as a rock. Makes others in this class look weak. I paid $350 which was a bargain!
N2NBT Rating: 2010-09-23
Solid, Quiet and Outperforms SB-200!! Time Owned: 3 to 6 months.
Wow! Very quiet and strong. Pair of 572's Puts out 650 Watts CW with 60 watts in. Tuned input makes this a joy with newer solid state rigs. Outperforms SB-200 and FL-2100 by a good margin. Overbuilt. The DTR-1200L is the real deal. Rare, but if you find one, don't think twice. Buy IT!
N5VU Rating: 2008-09-07
Okie Dokie Time Owned: 0 to 3 months.
Well, what can I say. Think Heathkit SB-201. It has two 572Bs and it will put out out 500+ watts with only 50-60 watts of drive. It has a nice enclosed cabinet. Very enclosed! The 3" muffin fan forces air inward throughout the RF section and it is suppose to circle back out to the holes adjacent to the muffin fan.?,?,... This appears to work OK however, the lid over the tubes gets really warm. I still like it though! This Dentron actually has a tuned input that gives your SS rig about a 1.4 SWR. Even with this small amount of reflected power, it still puts out a respectable signal. The meter is blue. Ep is 2000 volts idle and about 1750 under load. This is a 115 VAC situation. I know that it will be much more better when wired to 220 VAC.
The Ip scale is from 0-500 ma. Each tube pulls 250ma under load (250 + 250 = 500ma). I.e., "Full Scale" deflection. Thats still OK. Wierd, but OK.
Just like the SB-201, it has a relative power meter.
I solved the venting issue. I drilled many many holes and countersunk them. It kinda looks like a Clipperton L (I have one and I am keeping it.) Holes over the tube stack and holes on the outside (top of the tubes). The old 3" muffin sounded like a sewing machine, so I fashioned a 5" on to it. It even moves as much air as a Clipperton L now. Very very cool.
If I wasn't such an ampaholic, I would probably keep this one for a while. However, as it goes with us ampaholics, we keep moving on to stronger things.
Aw shucks, I probably should give it a 4.5 at the least. It is a very decent amp. If you get one, you will not regret it.
Even though we hams are suppose to use the minimum amount of power to carry on a contact,...and I'm fond of QRP too,...Life is much too short for QRP!.
God Bless America and those who gave us the ability to do so!

73, Marcel N5VU
AA2PR Rating: 2008-08-26
Awesome Small Amp Time Owned: 0 to 3 months.
One week with this amp that I got shipped from Montana. Great signal & audio reports with 75W driving power puts out 550W on 80M with a pair of Taylor 572B using 110VAC. I was surprised that in the 21 mhz band position I could load the amp into 18 and 24 mhz with 500W PEP. This is going to be a keeper, well built, the fan is very quiet and the previous owner modified the top cover with a opening for the heat to get out of the finals area and a metal screen installed that make this amp run cooler during operations. Mine has a serial number of #00176, I would like to know how many of this model Dentron made before closing the company. If you find one of this amps get it you will not be sorry.
KG4IZO Rating: 2007-05-25
Great Amp!! Time Owned: 0 to 3 months.
I have picked this amp up in a trade and so far i am very impressed with the quality of the amp smooth tuning and 700watts out with about 60 w input..Built rock solid,I am need of a manual for this amp so if anyone can help e-mail me at htjude@hotmail.com
N2YKX Rating: 2007-02-17
Commercial Grade Time Owned: 0 to 3 months.
I just picked up this amp for $325 and could not be any happier. Built like a brick !@#$% house.
All qualty components. The picture does not do it justice. Very compact and good looking piece of equipment. Getting full output from original Dentron 572B's. Gets 700 watts no problem, lofts at 500 where I run it. Makes my Yaesu FL-2100B look like a toy. This is a pretty rare amp if you see one pick it up you won't be sorry.
N7WR Rating: 2006-02-21
Great Buy Time Owned: 0 to 3 months.
I recently purchased a DTR-1200L in great cosmetic and electrical condition but with soft finals for a very reasonable price. A pair of new, matched, Taylor 572B's brought the output back up to 1400 Watts PEP. This amp is built to last. You could drive a small truck over it. It is beautiful with rack handles and a soft lit blue multi meter which reads Vp, Ip or output. 80-10 with tuned input. Heavy duty switches and velvet smooth load and tune variable caps.

This amp beats (appearance wise, cost wise, and performance wise) SB 200's and FL 2100's. There are a few out there as I saw another one sell within a day of my purchase.

Now if I could just get my hands on the matching tuner (DTR3K) I'd be a happy camper. It too has rack handles and dual soft lit blue meters. I missed one that was for sale just before I got this amp. If anyone has the tuner and would like to sell it please let me know.