| DO5DGH |
Rating:  |
2022-03-15 | |
| Back to the future with the Drake TR-7 |
Time Owned: more than 12 months. |
Back to the future with the Drake TR-7
In the meantime, the market is full of transceivers of all kinds and with extensive performance features, of which one would not have even dreamed as a radio amateur in the 1980-ies.
Quite differently it behaves with transceivers at the end of the 1970-iger years, which looked back only at the completely beginning of a transistor era. The TR-7 of Drake is such a transceiver of this time, which set for the first time completely on transistor technology and was considered as Game Changer. Today as then, such transceivers (fullx equiped) were very expensive and were sold at a purchase price of about 5,000 German Marks (*1) in specialized trade. That corresponds today to a purchase price of approximately 12,000 euro and was thus equal in the price range of a today's Hilberlings PT-8000.
About 10,600 units of the TR-7 were produced, until the Drake transceiver was discontinued under the type designation TR-7A at the end of the 1980s. Especially in Germany, the TR-7 was very popular due to the very favourable dollar exchange rate, so that even today via the classic sales portals a fantastic and pure analogue transceiver is available used.
High-quality analogue technology, which can still convince today. In particular, in this context, the large-signal receiver with an IP of 20 dB; the powerful RF output stage, which can handle hours of AM operation; large-dimensioned bandpass filters of high quality; very good passband tuning and a very present and effective communication modulation, to name.
Thus, the modulation of the TR-7 was often the distinguishing feature on the shortwave bands, which helped this transceiver to the quality pseudonym communication transceiver. This certainly also not unjustly, the TR-7 was sold not only as an amateur radio but also as a radio for commercial purposes. Especially for commercial applications a very good speech intelligibility, especially under difficult transmitting and receiving conditions, is at the top of the specification list.
Another distinguishing feature of the TR-7 is its external power supply of conventional design, equipped with a powerful transformer and as large as the transceiver itself, but significantly heavier. As with the HF power amplifier, the power supply was also very generously dimensioned and reliably delivers the required current and completely free of birdies or man-made noise of today's switching power supplies. The full-surface heatsinks on the left and right alone provide good passive cooling for high power requirements; if necessary the fan is switched on via a plug.
It goes without saying that modern DSP technology has become an indispensable part of our everyday radio life. Nevertheless, the analogue technology of the TR-7 has its own special charm and is completely free of digital AF processes. Especially this extraordinary presence, with which the RF signal is sent into the ether and received from it, that distinguishes the communication with the TR-7. The strongly modulated and 2.3 KHz (300-2600 Hz) narrow RF signal has a very high energy density (talk power), so that it very rarely requires a downstream high-frequency amplifier. A suitable microphone with linearly increasing frequency response is required; such as a Shure 450 Series 2.
Thus, a transceiver equipped with only basic functions can still hold its own, even with today's interference problems. Its high large-signal immunity, practical sensitivity, narrow ceramic and steep filters, effective passband tuning and, if necessary, an external NF-DSP (e.g. Lingua speech extractor) make this possible.
Back to the future - that's the title. If you now get involved with a Drake TR-7 that is about 40 years old, regardless of widespread opinions and preferences, then sooner or later you will come to the realization that it actually doesn't take much more or less radio equipment to successfully perform radio communications on the shortwave bands, even under difficult band conditions. It is always a pleasure for me to go on the air with my Drake TR-7, which looks almost as good as new, and to observe that the people I talk to have no trouble understanding my HF signal. What more could you want?
In this context it is important to note that a supposed interlocutor should adjust his filter bandwidth and passband according to his counterpart station. This is the only way to achieve the best possible communication on both sides. With a narrow filter and correctly adjusted passband, you will find that the supposedly too narrow audio profile of the received station will sound much more intelligible. Even the received station will thank you for it, because now it will also understand its interlocutor much more clearly. By the way, this is also the reason why I always name the filter passband from 300 Hz to 2600 Hz during QSOs with my TR-7. Safe, is safe.
PS.
Even if I am here big praise for the Drake TR-7, this should not hide the fact that this transceiver has of course also his problem places and there may be in some respects similar good and perhaps even better transceivers. But that is another story. What I would like to express, however, is that the TR-7 is still worth its money today, if it was maintained and not tinkered with.
(*1) Prices according to my internet research on the pages of www.wb4hfn.com and historical exchange calculator, a fully equipped transceiver cost in March 1980 as follows: TR-7 $1495, Aux-7 Board $45, NB-7 $90, 2x FAN $58, 3x Filter $165, PS -7 $259 and a Drake Stand Microphone $58. That makes a total of $2,170. In 1980, the exchange rate for 1 DM was approx. 50 US cents. That then makes $2,170 x exchange factor 2 = 4,340 German Marks + 14% customs/import tax of approx. 607 DM + around 100 DM shipping makes a total of around 5,047 DM
73 de Georg | DO5DGH
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| AC2YW |
Rating: |
2022-01-24 | |
| Classic look and great performance |
Time Owned: more than 12 months. |
This is one of the best looking classy transceivers out there with performance to match, and a great candidate if you're looking for an older rig to display and occasionally use in the shack. Mine was an eBay purchase that needed some work, but worth the challenge. I also caught the fever to complete the NB and the filters. Filters are available from nobleradio if 2.3KHz is a bit narrow. Also be warned that the 2.3 filter (and others) may be more narrow than what's stamped on top. I found their 2.8 filter to be a bit noisy on the high end, but nobleradio does make custom bandwidths and from what I remember, no or little extra charge.
The biggest drawback is the VFO drift, but there are vfo stabilizers for this. I decided to keep mine original. In fact, I encourage you refrain from mods, as it's not likely this will be your main rig for long or ever. A minor drawback is the audio quality. By itself it's fine, but when compare to a modern SDR rig in A/B testing, the SDR wins easily. That said, the radio was designed for communication audio only.
All other receiver parameters are great, like AGC, sensitivity, and selectivity. Unlike some early transistor rigs, the solid-state final is protected and tough to damage. The power supply is a tank.
Like many, I drooled over this rig as a kid, so had to get one. Also drooled over the R7 but those are a bit pricey, so keeping it to just one Drake in the family. The rig pairs well with a classic astatic lollypop microphone. I just changed the element to a condenser and kits are available on eBay. |
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| KG7M |
Rating: |
2020-12-26 | |
| 7-Line Twins |
Time Owned: more than 12 months. |
When the TR-7 came to the Amateur Radio market I was in my mid-20s and sold them at Joe Borsch's (W7PNS/SK) Portland Radio Supply Company. Despite my employee discount, they were out of my price range. I settled for a used set of B-Line Twins. Joe, and our Tech Dan Raab owned, and repaired the 7-Line. For many years after selling Portland Radio Joe was the guy to send your TR-7/R-7 to for repairs.
In 1993 I was employed at HP making a great living. I purchased my TR-7, and R-7, which I still own. I just restored both. The VCO Board JFETS had gone out on both - HI OSC on one and LO OSC on the other. The TR-7 is easy to repair and maintain if you take time to read the Service Manual. The TR-7 receives down to 5 kHz if you remember that the LF/VLF Antenna Connection is on one of the Cinch-Jones Connectors. And it's a joy to work DX on the Ham Bands. Mine is a high serial number, Split Back, with NB7A and all Filters.
I've owned a lot of fine transceivers and seperates over the years. The Drake TR-7 and R-7, used as Twins can work DX under very marginal conditions. Only the Ten-Tec Delta II, with it's 8-Pole Filter, comes close to digging a signal out of the mud. Most owners complain about drift. My Drake's drift for the first 30 minutes from a cold start, then remain solid enough to work FT8. The only Mods I've performed were to replace the incandescent Dial Lamps with LEDs. I simply removed the glass envelope from the dial lamps, and installed a small piece of perf board with either one or three Bright White LEDs. These plug in directly to the S-Meter and Dial Lamp Sockets. |
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| AC5XP |
Rating: |
2018-11-02 | |
| Excellent design from Drake, way ahead of its time! |
Time Owned: more than 12 months. |
The Drake TR7(A) is my all-time favorite vintage transceiver. I had one more than 20 years ago and always regretted selling it. But I recently was able to get a very nice one again with a high serial number, a Drake TR-7A, one of the last ones built. It had a problem but it was easily fixed (defect PIN diode switch for the calibration marker which caused a low output at 10 meters, a common problem with the Drake)
The Drake TR7 is an incredibly smart design, it was way ahead of its time when it came out. Drake really took a huge risk at the time by pushing the limit for an all-solid state, PLL synthesized rig. The radio has a couple of features that make it special. To list a few:
1)The PLL concept is really smart. A 500 kHz digital synthesizer is used, which generates the local fixed frequencies for each 500KHz band. A 500 kHz span VFO (5MHz to 5.5MHz) is then used INSIDE the PLL loop for the fine tuning inside a selected band. The SSB carrier frequency generation is also inside the mixing scheme, which means the rig’s output frequency cannot drift if the SSB carrier frequency drifts (which concept also allows for the nice working pass band tuning on this rig). The only radio that I am aware of that uses the same concept is the Kenwood TS-530S, hard to say who stole it from whom. In any case, the result is an exceptionally stable rig with derives everything from a 40 MHz fixed reference frequency, including the digital display counter time base. Of course, the VFO can still drift (albeit small), but when this happens the display will show the drift as well so that you can compensate for the drift manually. Most VFO tuned Japanese rigs of the time (and the Collins KWM-2A) did not have this scheme, which meant that the many local oscillators in those rigs were unlocked and each one of them would cause independent output drift on those rigs, without showing this on the display. Drake also did the right thing by NOT going for a fully synthesized system, the latter which was done by Collins for the KWM-380 (that rig has a digital synthesizer capable of 10 Hz steps). Because in those days, rigs designed with fully digitally synthesized tuning (also for the fine steps) suffered a lot of phase noise because direct-digital synthesizes (DDS) did not exist yet. As a result, the TR-7 VFO based system has a MUCH better receiver than the KWM-380 did with all its complexity. Quite an accomplishment considering the KWM380 was almost tree times more expensive than the Drake!
2)The Drake uses an up-converting concept, one of the first rigs to do this. As a result, it is general coverage from 500 kHz to 30 MHz, without manual front-end tuning being necessary. General coverage also extended to the transmitter (although the latter was blocked by Drake but easily defeated by the user). As a result, this rig also can be used on the WARC bands, despite its vintage.
3)The receiver uses a passive ringmixer without an RF preamp in the RF front-end. Don’t ask me how they did it but this resulted in a sensitive rig nevertheless, even on 10 meters. The result is a bullet-proof front-end. This rig STILL is one of the better rigs when it comes to large signal handling and absence of phase noise.
4)The rig is built REALLY well. Nice made-in the-USA all aluminum construction and quality. Especially when you consider that this rig was less than half the price of the competing KWM-380. Drake did a MUCH better job than Collins finding the right price-performance balance.
5)Last but not least, I lust LOVE the cosmetics of this rig. It was way different than anything else on the market at the time. And it still is. Ten-Tec copied the concept more or less (same extruded aluminum front panels), but the Drake always looked the coolest.
I kept my radio 100% original, NO mods. You should not do that either if you value the history of these vintage rigs. The only thing I did was replacing the AC fan with a modern DC brushless fan, since these DC fans are less bulky and quieter. And if needed, the original AC fan is easily re-installed. 12V DC for a DC fan can be obtained from the auxiliary port on the back of the rig (12 pin Jones connector) so there are no mods needed to the rig when installing such a DC fan. Using a DC fan also means you can operate the radio from any 12V 30A DC source (I use an Alicino PSU) without the need for the large and heavy Drake PS-7 supply. Because the original AC fan ONLY runs when you use the Drake PS-7 supply with it.
A tempting mod could be the installation of the huff-and-puff VFO stabilizer, many hams have actually done this. It eliminates the TR-7’s VFO drift. However, the VFO drift is so small to begin with that I do not think this justifies violating the rig’s originality. If you are into vintage equipment, you need to accept its shortcomings. Because, if I want a rock-stable QSO, I will use my state-of-the-art $4000 Japanese rig -that is not what vintage equipment is all about!
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| WD5ACP |
Rating: |
2018-02-04 | |
| Classic rig - still valuable! |
Time Owned: more than 12 months. |
I picked up a TR-7 (split-back) about 2 years ago. It's a rig I wanted way back when it was introduced into the market (Fully solid-state! No tune! Up-conversion!)
The example I have was already modified. It was opened for 3-30 mHz transmit and someone had replaced the incandescent bulbs with cool-blue LEDs. It looks great in the shack! Right after I purchased it I modified it a little more. I re-tasked the STORE button to key the radio in CW mode (great for tuning amps and antennas) and then I added the wonderful X-LOCK kit from Cumbria designs. An easy Heathkit-ish board to build and easy to tie into the TR-7. Once installed, once you let go of the VFO knob, the PLL locks and eliminates any drift (common on radios with analog VFO/BFOs). Out the box, the TR-7 is very good, but the audio isn't exactly up to today's standard with the stock 2.3 kHz IF filter. I recently added a Sherwood 2.85 kHz IF filter (in the standard position it's for both transmit and receive) and WOW - I've been getting great audio reports, and on receive it's much better too! This is a highly recommended MOD for everyone still using the stock filter. You'll do best if you avoid the Drake external speaker - it's an open back design and isn't very good (even if you close the back, it's still not very good).
One other quirk... this rig is a mother-board design with most of the radio built on plug-in circuit boards (with LOTs of connectors). Unfortunately Drake didn't bother to gold-plate the connectors so if you have a TR-7 buy stock in Deoxit-5 and be prepared to pull the boards/connectors out every year or two and douse them with Deoxit.
Finn ally a note about the PA & accessory power supply on the rig. Its' a freaking tank. I suspect Drake didn't want to stumble out of the gate with the first solid-state rig - so they over-built the thing. Expect 140+ watts out on the 40/80 bands!
So it's not perfect - there's no speech processor (the external one isn't very good) - though it really doesn't need one. - No DSP - though as mentioned by others the Pass-Band tuning is VERY good - -but it holds it's own - even against my primary Kenwood TS-590 - it's a joy to use and a nice vintage radio that was Made in 'Merica and is still useful today (with a few tweaks and mods). If you like Drake - these are good ones (look for the TR_7A models - split-backs, as they have the better circuit boards) - Enjoy! |
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| ZS1ZC |
Rating: |
2016-07-20 | |
| Game-changer in its time |
Time Owned: 3 to 6 months. |
The Drake TR7 - a modern classic. I've been wanting one of these ever since I got the TR-4C two years ago. I was discussing it on the air last year during a 20m opening to the US, and a day or so later got an email from Stu, K8ST, who had been listening, saying he had a near-mint condition TR7 with accessories looking for a home . Well, we did the deal and shipped her over - what a beauty! At serial #4774 it's quite an early build (1979), and it spent its life no more than five miles from the plant where it was made.
It's hard to explain the appeal of Drakes but somehow the TR7 takes it to a different level. It really isn't a fancy piece of kit, but it represents an epoch change in the design of amateur equipment. Firstly, it's all semiconductor, one of the first non-tube rigs on the market. And the Sherwood figures really aren't bad for the era, it's up there with the big names of the time in performance. The look of it is almost homebrew, there's no moulded front panel like the Kenwoods used, it's all metal sheet and extrusions, nothing sophisticated. But the performance for the technology is brilliant. Somehow those guys in Ohio really thought this one through and produced a game-changer that has a functional balance that designers have followed for years since.
Based on limited use so far, sensitivity is good, no stability issues, audio is nice and clean both ways. I see 100W+ output as expected. One noticeable feature is the NB7 noise blanker that absolutely kills pulses from neighbours' electric fencing, it's really effective. Then there's the PBT... I rarely use the IF shift on my TS830S, but the Passband Tuning on the Drake just begs to be turned on it's so effective. I run it as a second channel on the Kenwood SP-230. Also have the SP-75 Speech Processor that I'm still setting up. First QSO was Heard Island on 20m.
One minor hitch.... it wasn't switching my linear amplifier (or rather, it was half triggering the amplifier relay in receive, triggering it fully on transmit and then not releasing it) - but a bit of troubleshooting revealed a ceramic decoupling capacitor on the Cinch-Jones connector inside the rig that seems to have partially shorted. A quick replacement, now there's no problem - I guess it's age, this girl was made nearly forty years ago. She drives my NEC tube amp to legal limit with ease, no problems with the output match at all.
It's not a perfect transceiver compared to modern designs, but it's pretty damn good - and for its era it is superb. Hence the 5/5. |
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| W6PMR |
Rating: |
2015-01-26 | |
| Great old radio. |
Time Owned: more than 12 months. |
I would rather have a TR-7 than any Drake tube
radio. One of the all time great older rigs.
I could go on and on about how good these are
but you get the hint by now. |
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| AA7LV |
Rating: |
2014-05-07 | |
| A Ham Classic |
Time Owned: more than 12 months. |
Owned a TR7 R7 L7 station tenh years ago
I sold it for an Elecraft K3/10 kit.
But the Drake Tr7 station is my favorite
Transceiver Receiver and Linear for the price of the loaded K3/100.
So I just bought another TR7
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Earlier 5-star review posted by AA7LV on 2009-01-09
I have had my TR-7 for 3 months now. It hears whatever is out there and puts out over 100 watts. Best of all it is user..serviceable!
Plug in circuit boards and readily available spares means never having to say your sorry you bought it. If it were a basket case you could sell the good boards for more than the price of the radio.No bad for a 30 year old radio.Just added an L-7 if I need more than 100-150 watts. WHAT MORE COULD A CHEAP HAM ASK FOR?!?! |
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| WA7DUY |
Rating: |
2012-10-05 | |
| An excellent solid rig |
Time Owned: more than 12 months. |
| I bought my TR7 new in the late 70's. I got one of the first off the line (#762) and still have it. It is and was a very well built American radio. It had no bells and whistles by todays standards. I bought it to use on Mars frequencies. The stability was second to none. I kept hearing that was not the norm but mine was super stable. It has one of the best receivers that I have ever owned and was very easy to use. The replacement displays were a problem to find replacements but now Willi Raas sells an excellent set. The rig is easy to work on. The one drawback was the use of the Molex pins and headers. Often the repair is to pull the boards out and push them back in to remove oxidation from the pins. I now also own a second TR7 and I still think it is a fantastic radio and very underpriced for what it does. |
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| WD9CMD |
Rating: |
2010-06-28 | |
| Hard to beat a TR7 |
Time Owned: more than 12 months. |
A wonderfull American Made Radio !
Currently have my TR7 alongside a new TT Omni VII and a pristing TR4C on the shelf above both. I must say as for operating convenience, and chasing DX, the Omni VII is the first rig on line. However, last weekend, during field day, I did some experimenting. Well, just purely as a receiver, that old TR7 still works very well indeed. Interestingly, the TR4C hears most anything the TR7 hears.
I do enjoy the receive audio more on the TR4C than any of the rest, and the TR7 is nearly as good. Not saying the Omni VII is not a fine radio,....its among the very best, and I feel very fortunate to own one. But lets not forget its a new rig versus a TR7 thats over 30 years old and older yet for the TR4C.
As for maintenance, either the TR4C or the TR7 needs some TLC, either by you, or from a list of excellent technicians. Yes the TR7 takes some effort to operate, and no DSP, but its a pleasure to use, a pleasure to listen to, and a pleasure for others to hear you.
These are great for a new ham, a collector, or someone who appreciates a rock solid american made product of days gone by. If you want the latest bells and whisles, or are into contesting, then of course, you should look to the new rigs only. Sorry,....no PC control or computer logging with a TR7. Just a pencil and a old fashioned log book.
If you find one in good condition, it just may be a lifetime keeper!
Good luck ! |
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