Makere's Amateur Radio Review
David White has spent a lot of time designing receivers. He saw a golden opportunity when the latest in amps, MMIC's came about. This receiver is the result of his effort and the Monolithic Microwave IC. It is a wonderfully versatile little jewel that, for its price of about $40, exceeds just about anything out there.
In the middle of the large 4.5 by 6.5 inch silk screened board is a prototyping section for the builder to place any kind of mod he or she could dream of. How about varactor tuning? There's room. An RF amplifier? Go ahead and put it on there. There's enough room for an audio pre-amp--just in case the on-board sound isn't enough!
This is no cheap Direct Conversion POS. It is a super superhet. David designed it with experimenters in mind -- It is actually possible to get your fingers between the components!!
What I like about the rig, besides the car-stereo-type audio, is the fact that this baby is broadbanded. I mean, it is .....BROADBAND.
David recommends building the receiver for 40 meters and going from there. To change bands, all you need to do is to make some minor changes in the VFO and a toroid coil. It will cover all of the HF bands plus Six meters and possibly beyond, if you can coax the VFO into it. Once you get above 100MHZ the broadband transformers get a bit "lossy" but, shoot, David tells me that the MMIC's have a range of just above DC to visible light!
Other features that David has incorporated in the rig include 10MHZ crystal filtering and reception of WWV by inserting a jumper across the input trap. Me thinks that this latter feature was no more a planned byproduct than I was to 40 year parents.
To purchase the Tanner/White receiver, call Tanner Electronics in Dallas, Tx at (214-242-8702.
The following is a excerpt from a letter written by Michael Hopkins, AB5L to George Dobbs, QRPp Magazine.
I own kit number two. I bought it off the back of a Coup DeVille Convertible (early '70's I think) Saturday from the designer at one of Dallas/Fort Worth's weekend hamfests. Tanners is an electrical surplus dealer not to be confused with 800 number super store Tucker's which is also local. I don't need the kit and I haven't built it, but I had to have it. It would be a slight to providence if I did not buy it after all the speeches I have made about the need for such things. If this is not the Messiah of homebrew hamkits, it is close. Just look:
The circuit board, for a two-xtal single-band RX, measures 4 1/2 by over 6 inches. A view camera takes a smaller sheet of film! It is also at least 1/16 thick and the screened lettering jumps out at you. I lauded Ten Tec's new model 1056 DC RX as a Godsend to newcomers, and its board is just 6 by 2 1/8. The Tanner/White is over twice as big and it is meatier in some other aspects, too. Look at audio. An NN1G Benson from the '95 Handbook uses the ubiquitous LM-386 audio chip that hides in a Radio Shack telephone amplifier. It is good for 200mw and will fill your headphones, I agree, but look at the Tanner/White. What is a TDA2002? It looks like something from a car radio and requires a heatsink a third the size of the NN1G's receiver board.... When I built Lewallen's DC RX from the l978 Understanding Amateur Radio, I spent two days learning it needed and audio amp -- everything worked, but I could not hear it.
I do not see any techno breakthroughs on the Tanner/White. It uses a two crystal filter and a couple of NE602s, but the 10MHZ trap on the front end is a good wrinkle and he shows how to defeat it for WWV if you build it for 80, 40, 20 or 17 Meters with the supplied 10MHZ xtals. My friend, AA5ZD, who hates to wind toroids, will be glad to know that this board has but two and they are the big old T80-6 models instead of the smaller items that are best used in muzzle loading shotguns to clear Starlings from your Field Day Site. Downstream from the two xtal filter is a MMIC for a IF amp. This is state of the art for homebrewers as Al Ward wrote them up for QST in '87. They allow one fellow to sell a $5 broadband preamp kit with a 1 x 1 3/4 inch board. I think that is great and welcome a new friend, but if one wants to use one of Doug DeMaw's dusty old CA-3028A's, or just about anything else, there is a huge kluge area which includes two DIP sockets and over 50 pre-drilled pads. I could easily build in a G-QRP style transmitter, a keyer and 4 more poles of filter and still have room for the NE602 6 Meter converter from QRP Quarterly, but that is not the point. Short call Extras, who infest the QRP movement, are not the folks for whom the Tanner/White is such good news. We will, even with failing eyesight, get just about anything to work. But what about the newcomer? The jaded old timer who was a Conditional? It is the Model A where the Sudden/Neophyte was the Model T Ford -- A generic circuit executed on an expansive board with exhaustive documents.
But if I laud White more, it does not mean I salute Breed and Benson less. Benson, for instance, started down this path, but he veered first to transceiver and then to miniaturization. Both those choices are enemies of an entry level/utility type project. An NN1G, one to which is in the '95 Handbook, is the most thought over and refined kit this side of the Atlantic, but it fails on one level. Dave told the Dayton audience he was trying to offer the simplest useful transceiver kit possible. I think he did it, but I also think he is like one of Gorge Raft's victims in a film noir. He knows too much. Sure, it is almost as easy to build a transceiver as a receiver technically, but hams do not operate only at the technical level. The psychological jump to the transceiver is a league. Lewallen simplified T/R switching, but two diodes are still much harder to think about than a slide switch. It is a tragedy to lose someone who started out to build a 'simple' receiver but abandoned it because he did not understand fast attack AGC. He didn't need to. He needed confidence: The confidence coming from a big easy board that will work. I find joy in the fact that it has arrived and I hope it is not too late.
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