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My Introductory Post

Hello! :-)

In an effort to help me learn more about electronics than I already know, not a whole lot at this point, I am going to build something with which I can use once I finally get my ticket. I downloaded and read a bunch of reference books on eMule and have learned a lot more than I stared with.

In search for helpful documentation, I found a book by Randy L. Henderson, titled "Build Your Own Intelligent Amateur Radio Transceiver". While now 10 years old, the book has many outdated components, and other errors in the book. While a good design idea, I think it could be improved on to 2006/2007 standards in many ways.. which I will attempt to do. The rig is based on the 80C31 / 8051 family with a 27C64 EPROM in with a 7805 regulator, and 74LS373 on the computer board. The computer board also listed as having: a 1N4001, a

1N4148, a 2N2222A, a 2N2907, and lastly a SK3444. It also featured a 100,000uF memory backup capacitor and a 6.2v Zener. I'd like to be able to use a PIC 16F or an updated processor from say like AMTEL.

My basic dimensions for the chassis are 16.1875" W x 6.1875" H x 15" D.. so that will be the working envelope of whatever design I end up with. That's a pretty big space, and I like having space to work inside.

I'd originally thought about making it a planar type system with plug in modules, sort of like a PC Motherboard / Mainboard(s). Kind of like some military / industrial systems are built. This would be so that service / repair would be easy.

After some initial research on the internet about the project in this book, there were supposedly many errors in the publication that contained this project, and I'm not a designer or RF engineer, so I couldn't venture to say what all of them are.

One of the subjects I found inside the book covered a VCO which was mechanical and used a Optical Shaft Encoder. What are some good VCO designs for use from 100kHz through 30MHz?

I also need a way to be able to include controls for RF Gain, AGC, BFO, two VFO's, a Notch Filter, switching from SSB bands (USB or LSB), IF Shift / AF Gain, and a few other things and include passband tuning.. and at least 20 programmable memories.

Output for controls would be through RS-232 and/or a RJ45. I'm not sure about antenna connections but should be at least a 50 Ohm SO-239. I need to make sure it works with something like the Sony AN-1 active antenna though a mini phone jack, the same type thats used in headphones..

Well, anyhow this is my introductory post, and I'd love to hear your comments, suggestions, etc.

It would have some sort of a power supply that would do internal switching for 100 through 250v AC, through a IEC 320 type connector and then maybe also be able to use 12 through 14v DC for marine or automotive mobile use.

Greg B. g b o w n e 1 @ y a h o o . c o m (remove spaces)

Reply to
gbowne1
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You know, when most people would think of "improving" a *radio*, they'd first think of improving its *RF* performance. :-)

But I agree the 80C31 is a pretty long-in-the-tooth architecture, and updating the control to an AVR would be an improvement.

I wouldn't venture the same thing about a PIC, unless perhaps you use a dsPIC and start doing some signal processing...

There's a guy out there who built (and sells) an HF transceiver with a full PC motherboard, running Linux and driving some reasonably small, I dunno,

800x600? color LCD. The ironic thing is that there's often little more expense in going the "full blown PC" route these days than building your own custom microcontroller board once said microcontroller board starts needing, e.g., Ethernet, an LCD interface, megabytes of memory, etc. (What can still kill you is power consumption and size, but for a basestation radio this isn't a concern.)

For the HF ranges, there's a large number of DDS-based designs out there these days. Google "HF DDS Generator" and you'll get numerous quality results.

SO-239 really is the lowest of the low in the RF world; it's really only a notch up from Joerg's suggestion of using RCA jacks. :-) Both will work fine at HF.

---Joel

Reply to
Joel Kolstad

I did google just now some things using the keywards you suggested. Very interesting. I'll look in the top 150 results. I use webferret to do searches.

As far as other antenna terminals, I thought about other things like BNC, or an N connector. I've also seen RCA jacks, screw terminals, and 5/16" mini phono plug.

I saw the rigs by VE7CA, I6WJBI6YPK and the one in an old IBM PC/PC-XT Case built by Gary Pershin.. Very nice designs similar to what I would eventually like to accomplish.

I have always liked rigs like the Icom R70/R71 and Kenwood TS-830 and the R-5000. I also like the way some of the other rigs like the Watkins Johnson and Racal rigs operate too, as well as the way they look.

I read more about the design of Randy's rig. It has some method of PLL and VXO as well. I don't understand those topics very well either.. but I seem to be learning more as I go along.. whilest reading.

Greg Seattle, WA

Reply to
gbowne1

If instead you get an 8051 compatible from ATMEL you can get good tools, recent chips, the EPROM+RAM integrated on-chip AND the old software still works (mostly).

The 8031/51 was so popular that it still lives, your project will be much simpler if you do not radically change everything right off the bat.

Reply to
frithiof.jensen

I hadn't planned on making too many changes until I've narrowed down what things in the original design were not correct.. and/or could be done in better ways.

Greg

Reply to
gbowne1

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