Saturday, December 22, 2007

A day in the lab

I have a few AML 1900MHz amplifiers. They have 3 boards, one has the actual amplifier devices, one is a control board and one I can't readily tell. The control board has several parts that look like I can recycle:
  • Lattice ispLSI 2032 CPLD
  • Atmel AT89S53 8 bit microcontroller
  • 74HC541D Octal buffer, tri-state line driver
  • MAX489 Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceiver
  • XM03AB LMC6464 Quad Micropower, Rail-to-Rail Input and Output CMOS Operational Amplifier
  • LM2902D Single Supply Quad Operational Amplifier
  • LT 031 16601 - can't find... house part?
  • LT 024 364B14 - can't find... house part?
  • JM05AB ADC1038 10-Bit Serial I/O A/D Converters with Analog Multiplexer and Track/hold Function [Discontinued]
  • Summit S93X6Xs - really obsolete
I'm thinking of a visit to the Salvation Army for a toaster oven to strip this board.

On the ez430 front, Sigurd and Tommy have laid out an RS-232 interface. Sigurd is using an RS232 to TTL kit from NKC Electronics, and Tommy suggests a Maxim MAX3111E. Either way, I need to build up a board to interface the ez430 ro the outside world.

Spent a bit of time looking at my new 8-12.4 GHz mixer. It's an Anaren 7A0128, an eBay special. I hope to use it to mix 144.100 with 10224 to get 10368.100. At first blush, I put +7dBm LO (10224 from a microwave brick) and 0dBm IF (Yaesu FT-290RII) and looked at it with an HP 432. Almost nothing. Rats. What the heck. Hook it up to the HP 141T and see what I can see. There's a mixing product all right, but it's down around -30dBm. Need to look at it some more. I could really use a signal generator in the 432MHz range, or maybe 1296MHz. Too bad my 1296 transverter isn't finished :-( Maybe I ought to make an 1152 source and finish it!

In random link stumbling, came across Solder Smoke, where two hams podcast discussions about workbench projects. Also, W7ZOI's page, from the EMRFD book.

Thursday, December 20, 2007

Experimental Methods in RF Design


Experimental Methods in RF Design by Wes Hayward, Rick Campbell and Bob Larkin. I've been reading and reading and reading. What an incredible book. I've learnt so much stuff, it's hard to praise this enough. I have a good head for digital electronics, but RF is voodoo. These guys do a great job. I'm making a shopping list so I can start building some of the gear they so lovingly explain.

Way recommended!