• You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.
  • Click here to find out how to win free radios from Retevis!

Rf sampler smoked out my radio

Also the video that BBB posted should help you understand a lot more about what you are dealing with!!! Watch it until it makes 110% sense!!
 
I'm beginning to think you should have bought some knitting needles and yarn instead of a scope. Sorry but I have offered all I can. It is a simple solution I know it and I am sure that if I was hands on there it would be solved in a few minutes with a few simple hands-on tests that I have done numerous times. There is definitely an issue with the grounds in your set up. Someone with a good knowledge of electrical principals should be able to find and solve the problem in short order be-it no ground or reversed neutral/hot leads. Time to call an electrician and let someone who knows what they are doing look at it for you. I don't want to be known as the guy that gave you info that resulted in your electrocuting yourself because you didn't know what you were doing. In the meantime I wouldn't use that scope. It's not junk it simply is incompatible with whatever you have for AC distribution in your home.
Yeah no worries, I bought the scope for shits and giggles and to learn something new... I have no problems using it for target practise. Maybe your right, I should stick to my day job instead of geeking out on a scope.
 
Don't get discouraged. I am in no way calling you dumb!! What you are doing is learning and asking questions. It's hard to help with AC power issues over the internet like this though as it's a dangerous deal!! We all start somewhere!! Majority of he time that is at the bottom, either by learning from mistakes, to admins questions. The only stupid questions are the ones not asked!!! Just put the scope down for a few days and then come back to it when you clear your head and also have some some more reading and research. This is JMHO. But don't ever let someone tell took you're dumb, and if they do, use it as a motivation tool to get your learn on man!! Keep your head up and again, don't be so discouraged. AC power isn't something you want to mess with when you are not in a clear state of mind per say. Just cool down for a few and the scope will still be there, when you feel
like tackling it again. But like Tallman said, it might be a good idea to find someone that can work on that type of equipment or can help you more hands on.
 
  • Like
Reactions: StrangeBrew
Yeah I learned a lot throughout this saga. Thanks to everyone for their input! I'm just a dumb ass oil rigger with a new cb radio hobby.
I object to that statement!!!!!
Dude put your feelings of inadequacy aside and continue learning.
I used to work the oil patch back in the mid 70's. I worked for (At the time #1 wire logger service) as an engineer for the well logging service.
I worked for six weeks as an "Attic Rat" on a triple stand rig in South Texas and I didn't know a single thing about the oil patch. If you would like I could give you my phone number and talk you through some test. First: "Do not shoot the scope" this usually turns a good piece of equipment to a boat anchor.
 
Last edited:
I object to that statement!!!!!
Dude put your feelings of inadequacy aside and continue learning.
I used to work the oil patch back in the mid 70's. I worked for (At the time #1 wire logger service) as an engineer for the well logging service.
I worked for six weeks as an "Attic Rat" on a triple stand rig in South Texas and I didn't know a single thing about the oil patch. If you would like I could give you my phone number and talk you through some test. First: "Do not shoot the scope" this usually turns a good piece of equipment to a boat anchor.
Right on! That must have been some primitive equipment to wire line back in 70s. Lol yeah nothing like working up in the derricks for weeks on end.... gets pretty lonely. But I haven't decided what I'm going to do with the scope yet, I'm just going to forget about it for a few days. That would be cool though if you could give me some pointers at a later date, I'd really appreciate it. Thanks!
 
Right on! That must have been some primitive equipment to wire line back in 70s. Lol yeah nothing like working up in the derricks for weeks on end.... gets pretty lonely. But I haven't decided what I'm going to do with the scope yet, I'm just going to forget about it for a few days. That would be cool though if you could give me some pointers at a later date, I'd really appreciate it. Thanks!
I worked mostly land based logging but from time to time had to log wells offshore. Yup it was primitive gear all right. We had an analog computer and the logging results were recorded on 12" wide KODAK black and white film. Some of the logs films were over 20 feet long. Those films were laid over the top of yellow paper and developed over UV light and ammonia based vapors. Just like the blue line prints for engineering and architectural drawings. I did that that work for five years until the oil field bust.
There was a joke going around at that time,"Do you know the difference between a Texas Oil field man and a bird?"



The bird can still make a deposit on a Mercedes!
 
Last edited:
They say a picture paints a thousand words so here's one I knocked up and use. My home brew RF sampler is made from nothing more than a few resistors and a few antenna sockets. The 2.2kOhm resistor I robbed from an old PSU, the other two resistors are just 100 Ohm 0.25W ones. It gives me -39dB of attenuation out of the BNC connector so I can use it on both my spectrum analyser and oscilloscope with up to a 1KW transmitter. Varying the 2.2kOhm resistor will vary the attenuation you get and there's no need to use a 5 watt one like I have, its just that you really want one rated at least 1 watt and I only had 0.25W ones other than this - remember there's not really much current flowing through it at all even when you're using a 1kW transmitter, its mostly performing a voltage dropping function. The two 100 Ohm resistors in parallel are to ensure that there is a 50 Ohm impedance on the BNC socket. Only downside is because of the type of resistor I used its only consistent for HF/6m because the resistors start to have lower impedance as the frequency increases so by the time you get to 145MHz its dropped to 35dB and by the time you're at 433MHz its down to -30dB.
j3I4U89l.jpg
 
They say a picture paints a thousand words so here's one I knocked up and use. My home brew RF sampler is made from nothing more than a few resistors and a few antenna sockets. The 2.2kOhm resistor I robbed from an old PSU, the other two resistors are just 100 Ohm 0.25W ones. It gives me -39dB of attenuation out of the BNC connector so I can use it on both my spectrum analyser and oscilloscope with up to a 1KW transmitter. Varying the 2.2kOhm resistor will vary the attenuation you get and there's no need to use a 5 watt one like I have, its just that you really want one rated at least 1 watt and I only had 0.25W ones other than this - remember there's not really much current flowing through it at all even when you're using a 1kW transmitter, its mostly performing a voltage dropping function. The two 100 Ohm resistors in parallel are to ensure that there is a 50 Ohm impedance on the BNC socket. Only downside is because of the type of resistor I used its only consistent for HF/6m because the resistors start to have lower impedance as the frequency increases so by the time you get to 145MHz its dropped to 35dB and by the time you're at 433MHz its down to -30dB.
j3I4U89l.jpg
Center conductor thru a resistor to ground?!?
NOT good!!!!!
That is a load.

Never mind; got a better look at the picture.
 
Last edited:
The two 100 Ohm resistors in parallel are to ensure that there is a 50 Ohm impedance on the BNC socket.

M0G -

Just a question: why do you need a 50 ohm impedance on the BNC connector ?? A 'scope or a spec analyzer do not need to look into a 50 ohm load ... or do they ?? To me this setup will just attenuate the signal more, because it is actually a voltage divider.

- 399
 
M0G -

Just a question: why do you need a 50 ohm impedance on the BNC connector ?? A 'scope or a spec analyzer do not need to look into a 50 ohm load ... or do they ?? To me this setup will just attenuate the signal more, because it is actually a voltage divider.

- 399

Depends on what you're doing. Mine is an all rounder which I also use on radio test gear to allow me to use something that is designed to work with a low input on linears so for example I can use it with my spectrum analyser or my Marconi 2955 to see how bad a signal a linear is outputting.
 

dxChat
Help Users
  • No one is chatting at the moment.