RF Sampler

[GnG8d]

It doesn't matter what the connection is between the jack and the resistor as long as the toroid will fit over it. i did mine years ago and don't remember if I left it as a strap or changed over to a more flexible wire but either way it will work.

I took the strap out and changed it to a wire for the toroid. There aint a whole lot of room in there, so I had to pull the resistor and mount. One thing I didn't take into account, is that the strap bent into an "L" actually held that end of the resistor up

 

[Robb]

OK - its a 100 ohm resistor.
But is it a metal film 2 watt or 5 watt resistor?

 

[Captain Kilowatt]

OK - its a 100 ohm resistor.
But is it a metal film 2 watt or 5 watt resistor?

Value doesn't matter as all it does is drop the voltage going into the scope and as long as the scope will handle it then fine. I can't believe the sample voltage will ever be high enough to damage the scope however unless unGodly power is used. As for power rating even 1/4 watt will do as there is no current being drawn by the scope.

 

[GnG8d]

Here is how the dummy load sampler turned out BTW.

 

[MrSuburban]

I drilled a hole mounted the bnc made a 1 turn 1" ID coil inside connected to center of bnc and ground. works like a champ.

 

[Crusher]

I was wondering what mix toroid everyone used. wish i knew about this a week or so ago. just bought a sampler that fits slug for a bird and one that connects to side of meter. Going to build a couple of these as well.

 

[Kamikaze]

A toroid is good for lower power. You really don't need it with anything over 10 watts at 30 mhz. A turn or two around the insulated center conductor will output a few volts at 1 kw into 50 ohm terminations.

 

[Crusher]

Ok, good to know. A friend told me the same thing. I was just double checking. Needed something to monitor a 6000.

 

[LeapFrog]

Im almost ready to view my carrier on the 'scope!
I know this is an OLD thread but most posters involved are still active, my question is: is this an "inductive" sampler because of the toroid transformer? And what should I build?

Compared to this resistor divider / capacitive coupled sampler designed by a Bob Heil (K9EID) I noticed in Ham Nation episode #110.
Schematic and overview found here
http://n9sja.com/2013/10/06/rf-oscilloscope-sampler/

For around 27-28 Mhz would I be ok using the design wich uses resistors and a capacitor or should I build the one Moleculo posted?
Advantages/Disadvantages to each design?

 

[BBB]

If others don't want to construct a device, Rf Parts (and others) supply a Unidapt brand RF sampler that works great and can be had for less than $50. Just select and order what coax connectors connectors you want to use on the inline device.

https://www.rfparts.com/rfa4059a1.html

 

[LeapFrog]

A very valid point by BBB one could be had for a fair price, any ideas on this:

For around 27-28 Mhz would I be ok using the Bob Heil (K9EID) design or should I build the one Moleculo posted?
Advantages/Disadvantages to each design?

Thanks

 

[LeapFrog]

A very valid point by BBB one could be had for a fair price, any ideas on this:
Thanks

Well I learned the hard way that I cannot edit my post this long after I sent it.

For Low Power 1-5 Watts, and 11 meter frequencies should I build wich style?

 

[Old_Crow]

I used this for CB channels and it was less than $10 to make

I made 1 change,put a 20K pot instead of the resistor to ground. Works great!

 

[LeapFrog]

I used this for CB channels and it was less than $10 to make
View attachment 18268
I made 1 change,put a 20K pot instead of the resistor to ground. Works great!

Old Crow Thank you, I will build the design published by K9EID.
That potentiometer to ground allows for adjustments to be made, what does the variable compensate for/ allow for over the fixed value. Different power levels? It basically forms a voltage divider I can see that, just curious why the added ability to change the resistance?

 

[BBB]

The Unidapt RF Samplers are adjustable as well by loosening the lock ring on the BNC connector shaft then slide the BNC connector in or out for more or less sensitivity.

Good luck with your home brew unit