View Full Version : Drake TR-7

04-14-2011, 12:12 PM
Got mine last October (2010). The price was $400 pluse $125 for the remote VFO. Plus, the guy threw in an MN-7 tuner....like, I reallly needed another tuner...already had 5! But it's pretty next to the other 7's, especially the wattmeter.

That radio has become my radio of choice. Like everybody else says about it, the receiver is a dream! It's got a really, really nice, velvety smooth sound, great AGC action and it's QUIET!!!! Finally, I've learned about phase noise, I think. Guess I was just used to hearing it. That is, intil I spent some time listening to the Drake (all of 5 minutes worth). Like I said in the other thread, the sound of that receiver is indescribably sweet.

The transmitter is totally bulletproof. You can't break it and it won't crap out. The heat sink (internal...not hanging outside) is MASSIVE and HEAVY. It's also over-built. It'll do more than factory spec output...but it's derated for reliability.

I haven't noticed any drift, but then I haven't really listened closely to notice what it does. It's always been just fine from turn-on.

The knobs are big and feel great. No menus. Built in forward/reflected power meter.

It's easy to work on, if needed. Mostly conventional parts (no SMD's!!!) on circuit boards with nice, big pads and traces.

The receiver is general coverage* and what's more, it's easy to have a "no filter" position (one resistor). That gives extraordinary AM sound.

*If you get a '7, make sure it's got the digital readout. That was an option in the early days of the radio, so there may still be some out there without it. They're probably unobtainium now, so unless the price of a TR-7 w/o the readout is next to "free", it's probably not worth it. Plus...without the digital readout, you don't get general coverage.

My radio has a serial no. < 600...must have been a very early one. But it's still cranking along like it just came from the factory. There's plenty of info and support available on the web and that, plus the way the radio's built makes servicing them a sweet, fun experience.

I don't have the noise blanker, but I understand that the NB-7 is one of the best out there.

Guess you can tell, I'm madly in love with that radio and when I head out on the road it's ALWAYS my rig of choice. It's big and heavy -- but in my application there's plenty of room on the passenger side for it to sit on top of a carry-on bag leaning against the seat. That makes the "heavy" part a plus...keeps it sitting there and it doesn't move around. The only hard part of taking it mobile is it needs LOTS of juice. It's rated at needing 25 Amps and that dictates AT LEAST 8 ga wire to the battery. I made up a cable of 10 ga & it's only marginal (but usable).

Thinking of all the possible mobile radios, I can't think of one that I'd rather have. There's the KWM-2, of course, and there's one of them in my future (I hope)...but it won't do general coverage. There's all the solid state synthesized radios that perform phenomenallly well, but...somehow....subjectively, anyway...don't really "feel" like a radio. (Yea....lot of "OF-ness" in that...guess I'll always like turning a cap or coild slug to tune...feels more connected, somehow.)

I've got a TR-3 that I'm restoring...also have a couple of DC supplies for it. I'm going to love comparing the two radios. They're bookends -- Drake's first and last "TR"!

04-15-2011, 11:45 AM
Adding to this one a bit:

I currently own four TR7s, three TR5s and a bunch of peripherals for each. My only gripes with the rigs are -

1) Drift. From a cold start they'll take a couple hours to fully stabilize, and if your shack is cold and drafty it might take a bit longer. Most of mine fluctuate +/- 50hz from "center" throughout the course of the day once they're warmed up. Good enough for the CW and SSB op; maybe not for the RTTY/PacTOR/PSK crowd. Adding the RV7 or RV75 (better) or an aftermarket DDS unit is a solution, as are the various "VFO stabilizers" (X-Lock, et al) which are currently being marketed.

2) Lack of computer control/memories. For the average ragchewer or casual user this is not a problem. Though I've not fully implemented the construct into a sale-able item, I have put together a computer-controlled DDS unit which can control the TR5/TR7 through the Ext VFO connector and on the computer side can be set up to emulate a Kenwood or K2....this for use with HRD and the like. (Phase noise is going to be a bit of an issue with the DDS chip I've chosen, and I want to wait until AD releases something with a bit higher clock.)

3) No FM. Okay, this may not matter to most users...but darnit, even my lowly HR-2600 can be used to access our local 10M repeaters. (FWIW, the mode was being considered for implementation in production - this by one of the ex-Drake engineers whom I'm friends with. Alas, co$t $aving$ won the day.)

4) Exalted carrier AM. Really, guys? How much more effort would it have been to modulate the RF-PA pre-driver transistor instead of unbalancing the balanced modulator then attempting to cram the low-level signal through that 2.3KHz SSB filter? Two fixes exist: Said pre-driver modification, or fitting a 6KHz AM filter then adding steering logic to the mode switch so the wider filter is also selected on AM transmit. Then re-center the AM carrier (via adjustment on the VR-PBT board) and you're good to go. Just don't run much mic gain or you'll sound "mushy".

The pluses:

1) Filter selection independent of operating mode. Hit the appropriate button and select any one of four (or five, in the case of the R7) filters. I wish some of my other rigs offered this...

2) Passband tuning - true passband tuning. Want to TX LSB and RX USB? Hit the "PBT" button and turn the control. Try that trick with your YaeKenCom.

3) A noise blanker which really works. There are three different variants out in the marketplace - if you come across one with a 3-pole crystal filter installed on it, that's an NB-7A - and it won't work in a TR7.

4) Great audio - I run mine with a Drake 7077 (Astatic 1104) mic and get lots of unsolicited comments on the audio quality.

5) A front end which is crunch-proof - no RF amplifier; direct-mix scheme results in a rig which can be used in close proximity to other HF transmitters without being de-sensed.

The TR7/R7 "twins" station was the rig I always dreamed of owning when in high school. I bought and restored many 7-line pieces over the past few years; eventually most will be passed on for others to enjoy. At least one setup will always remain - and I'll probably keep a couple.

04-16-2011, 05:07 PM
I just discovered the X-lock (http://www.cumbriadesigns.co.uk/x-lock.htm). There's information about putting that in a TR-7 on the web. It's reported that it will take the drift right down to zero from a cold start. Very interesting design -- probably would've stabilized a Swan 350 or even an Eico 753.

Just learned this week that the TR-7 doesn't unbalance the modulator for AM. What it does is it makes an USB signal, then re-injects the carrier after the filter. Incrementally better than just unbalancing the modulator...but it only gives you one sideband. I'm with you....wish they would've done "real" AM like the TR-3 & 4!

I've heard multiple times that the noise blanker is a really good one. I'll be on the lookout for that.