Signal Generator

[Bluejay1951]

I am new at this so if I do or say something wrong please let me know. I have been tinkering with CB radios for many years and I am looking to get a signal generator, I am looking at a FY6800 60 MHz Precision Digital DDS Dual-Channel function signal generator K6x9 on EBAY. Is this a good one.



Thanks Bluejay

 

[a417]

Judging by how that model number comes back to at least 4 separate brands I have never heard of, all of which stink of cheap equipment made of pure unadulterated chinesium..I think it's a crap shoot. One might be spectacularly accurate, next one might be complete crap. If you have access to a reliable service monitor thru a friend, you could always get it and throw it on there and see how accurate it is. If you get lucky, you might be ok...otherwise, buyer beware.

 

[prcguy]

It does a ton of things you would never use and not much you could use working on CBs. You need a generator that will do built in AM modulation with preferably an adjustable 1KHz and 400Hz tone with a modulation reference level and an accurate RF output down to at least .2uv or -121dBm. The Ebay unit will only go down to 1mv, which is over 1,000 X too high. You also want good frequency accuracy.

Also consider its best to have some attenuation between the radio and signal generator to protect it in case you accidentally transmit into the generator. Usually 30dB is good for this, so you might look for a 30dB power attenuator that will handle 20w or whatever your radios put out. When using this you have to take the 30dB into consideration when making receiver sensitivity measurements.

There are a number of CB specific signal generators you can get on Ebay for good prices. Some names to look for are B&K Precision, Meguro and Logimetrics. Or go for an older used HP/Agilent generator that will cover some ham bands in the future.

Edit: Or look for a good old used service monitor like a Singer FM10C that will not only generate a signal but measure some transmitter stuff.

 

[spongella]

I've had a number of RF signal generators for working on CBs and ham radios. A new one can cost a few hundred and go up from there. It all depends on your budget and how sophisticated you want it to be. I started out with one like this: https://www.tequipment.net/BK2005B.html?v=7375 . This is a basic analog unit, AM mode. It has an internal 1kHz modulator if you need a tone. My suggestion is to get a hold of some CB radio service manuals and see what equipment is required when doing maintenance and alignment. I'm a tinkerer like you but surely there are others with lots more experience who can give you sound advice. After many years of buying all sorts of new and even vintage test equipment I found a good used service monitor, the IFR 500A. That and a 'oscope is a good set of equipment.

 

[cmdrwill]

Way back in the CB days, '60's, I built a little crystal controlled oscillator in a double shielded box. I coupled out a low level signal to align receivers. Very handy in those days to see if a radio had good receive sensitivity.

 

[majoco]

A "function generator" is no use for radio work. You will need a proper RF signal generator than will have AM and FM modulation and RF frequencies from say 100kHz up to +500MHz, an attenuator that will go right down to 0.1uV so thats -117dBm and a metal case to keep the birdies out and in.