Quick simple DIY 50 OHM 16 watt dummy load

[Tallman]

Hey Captain my truck is in the drive way and I have plenty of refreshments available and it would be in the shade. BBQ can happen too!

 

[Tallman]

Here is a simple 16 watt 50 Ohm dummy load for your work bench.
Parts needed:
8- 100 Ohm 2 watt resistors
1- Small piece of RG8 50 Ohm coax
1- Small piece of pref board. Not needed but looks better.
1- Med bottle, Or what ever you want to put it in.
1- PL259, I have a quick connector attached to my PL259
View attachment 24351
View attachment 24353
View attachment 24354
View attachment 24355

This really good if you have a test bench and check your output with a oscilloscope.
Modulation checks are important if you modify the limiter circuits or you add a power mike, or the Negative Peak Compression circuits.

 

[Tallman]

Make sure they're carbon film resistors.
Wire wound won't work.

They do have non-inductive wire wound resistors.

 

[Crossbow]

This really good if you have a test bench and check your output with a oscilloscope.
Modulation checks are important if you modify the limiter circuits or you add a power mike, or the Negative Peak Compression circuits.

Yes Sir I have the bench setup with Scope, Freq counter, Signal gen and meters. If I remember right you was one of the ones that helped me get all that cool stuff!

 

[Tallman]

Yes Sir I have the bench setup with Scope, Freq counter, Signal gen and meters. If I remember right you was one of the ones that helped me get all that cool stuff!

You can blame me if you wish if it is keeping you out of hot water with your significant other.

 

[Crossbow]

You can blame me if you wish if it is keeping you out of hot water with your significant other.

Well, Umm... That is another story...LOL I have my eye on a new digital oscilloscope that I am trying to con her into letting me buy. So if I tell her Tallman said I have to have it then it should go over smooth right? Sounds good to me buddy! LMBO..

 

[Captain Kilowatt]

They do have non-inductive wire wound resistors.

Yeah but they tend to act a little "funny" up in the HF spectrum. Still not as good as good old carbon composite or carbon film types for RF.

 

[rabbiporkchop]

They do have non-inductive wire wound resistors.

I had no idea a non inductive coil existed.

 

[Tallman]

If you take 12" of wire and fold it in 1/2 and wind it starting at the joined end the inductance is cancelled. Just like twisting wire leads in a power supply.

 

[Captain Kilowatt]

I had no idea a non inductive coil existed.

If you take 12" of wire and fold it in 1/2 and wind it starting at the joined end the inductance is cancelled. Just like twisting wire leads in a power supply.

Or a dual layer coil wound in opposite directions will cancel out the inductance as well. I have found them to be great as accurate dummy loads for audio frequencies where you are dealing with several octaves but for RF they still cannot compare to the carbon composition or carbon film type.