Hookup RF Generator and Oscilloscope?? Help PLEASE.

For discussions on CB Radio Alignment and Tuning
Post Reply
YosemitySam
Dead Key
Dead Key
Posts: 47
Joined: Saturday 24th Feb 2007, 17:41
Location: Stixs

Hookup RF Generator and Oscilloscope?? Help PLEASE.

Post by YosemitySam »

I have been reading about Generators and Oscilloscopes. But, I am not having much luck finding what type of probes to use. I know that for recieve alignment you input RF into antenna and connect Oscope to speaker with 8ohm load. But, not sure how to hook up to show modulation. I assume of corse I will need a 50ohm load. But, what type of probes. Or, can I make a probe for this function. I am all wet behind the ears so please excuse my mistakes. All I need is a little help along the way. I'm open for any sugestions. Maybe you have a diagram or link that would help. Also do I have the right scope to do the job? What I have is a Tekronix 2225 50mhz Dual trace. Has vertical and horizontal. AM/FM Signal generator frequency 100khz-110mhz has internal modulation sorce. I may need a nother device maybe a Audio voltage meter?but, not sure. Any help would be great. I just won't to do It right Please Help. Thanks
timrim
Heavy User
Heavy User
Posts: 259
Joined: Thursday 29th May 2008, 10:11
Location: Ohio

Post by timrim »

I always simply use a X10 probe connected to the antenna jack for rf output measurements. Just make sure your probe is good to at least 40 mhz and you should be ok.
YosemitySam
Dead Key
Dead Key
Posts: 47
Joined: Saturday 24th Feb 2007, 17:41
Location: Stixs

Post by YosemitySam »

Thanks timrim, I have the probe. So, do you connect it direct to PL259? Do I need a dummy load for RF output measurements or just the probe & Oscope? Thanks!!
timrim
Heavy User
Heavy User
Posts: 259
Joined: Thursday 29th May 2008, 10:11
Location: Ohio

Post by timrim »

Yes, your radio will need to be on a 50 ohm dummy load, just clip the probe on the wire that goes from the circuit board to the SO239 jack. Remember to start on a high volts/div setting on the scope and work your way downward. A lot of the radios will read over 100 volts peak to peak or higher on the scope.
YosemitySam
Dead Key
Dead Key
Posts: 47
Joined: Saturday 24th Feb 2007, 17:41
Location: Stixs

Post by YosemitySam »

Thanks timrim, I understand now. You helped me out and pointed me in the right direction. Any other suggestions would be greatly apprecianted. Thanks for all the help!
ralph60
Newbie
Newbie
Posts: 5
Joined: Monday 1st Dec 2008, 16:21
Location: SO CA Beach Cities

Hookup RF Generator and Oscilloscope?? Help PLEASE.

Post by ralph60 »

you need to get a 50 ohm 15 to 20 watt 20db attenuator.

the thing is this kind of stuff is getting hard to find. all I can find are attenuator cables that range form 0 to 80 Ghz. they sell for $200.00 to $300.00.

a few years back you could buy a CB 50 ohm 20 db attenuator $25.00.
warhorse
Frequent Keyer
Frequent Keyer
Posts: 94
Joined: Sunday 23rd Apr 2006, 1:15
Location: uk

Hookup RF Generator and Oscilloscope?? Help PLEASE.

Post by warhorse »

Post Reply