James - great question! Think first you need to determine exactly what you'll use it for so you can set some parameters for what the generator will do and maybe more importantly how much it will cost. If you're simply looking for something to troubleshoot your Drake gear with you can probably get by pretty cheap....if you're looking for that and other applications the following may be a start as you think about what to get.
So you may want to ask yourself some of the following: How high does the generator have to go in frequency? (usually a good idea to at least double your first answer for the future!) How small/large does that signal have to be? How accurate does the output level need to be? Do I need small incremental changes (tenths of a .dB) or is the 10/20 dB switch sufficient? Do you need different modes of operation, i.e. AM, FM, I/Q, etc. In general there are probably five what I see to be different levels of generator available, with cost marking the major breakpoints. (1) For the lack of a better term, the "...couple hundred bucks" range. At the low end you'll find the typical Heathkit, Eico, B&K, Tenma models that generate almost up to 100 MHz and have sufficient harmonic output to work up into the 440 band (maybe). Great for general troubleshooting where accuracy and stability are not the driving factors. Probably have the ability to modulate the signal ala AM. (2) The "more than a couple of hundred bucks" range - now you're getting into either used HP generators, abundant over on ePay where it may be a real crapshoot but there are some gems to be had. If your bench is big enough the HP 8640B series is a good choice but they are VERY long in the tooth....having said that they're probably a mainstay of many ham workbenches. All depends on your comfort buying used test gear (and potentially your ability to troubleshoot and repair it). AM/FM modulation abounds. (3) The "small kilobuck range" - again mostly used equipment, higher frequency ranges up above 1 GHz and higher; more accuracy on output levels. Output attenuators tend to get fried and are then hard to repair/replace. Now you're starting into the boxes that you can tie to a cesium, rubidium, GPS standard (10 MHz for the most part) that will really ensure the output accuracy of your test signal. (4) The "major kilobuck range" - new instruments by Hameg and others. Ramsey used to have a nice model that would go almost up to 1296 MHz and was a good performer but now discontinued....used units may be around somewhere. (5) The "maxi kilobuck range" - new instruments by Rohde & Shwarz, Agilent, Textronix and used units. I've had good luck here by going direct to the manufacturer's sales department to see if they had any demo units available....they can be had if you luck into one for significant discounts. Ok, enough rambling....am sure we'll get plenty of other advice here shortly. Hope this was more helpful than a hindrance to your effort! 'Course I may be all wet here....what do you other guys think? 73 -- Dino KL0S On 9Feb2010, at 12:55 PM, James Bridgers wrote: > I would like to have a rf signal generator for my use. Any suggestions as > what to look for? > > Thanks in advance for your help _______________________________________________ Drakelist mailing list [email protected] http://mailman.zerobeat.net/mailman/listinfo/drakelist
