Weber bias tool

Keep us posted peoples I certainly wont be using it till i find out the production dates of the faulty ones. Australian , Aug 18, Ok I'm buying a Fluke meter , I'm convinced. Joined: Jul 15, Messages: 1, Likes Received: FWIW, one good place to buy a nice expensive Fluke multimeter is in a pawn shop no kidding. The reason is they are built like tanks, and they are hard to blow up. You have a good chance of getting a fine meter at a low price. The reason it was so cheap was several of the ranges didn't work.

Turns out Fluke meters have internal fuses not accessible without taking the meter apart, these were all blown in the meter. I replaced these and checked the meter on a calibrator, all the ranges were then within spec. It has worked perfectly for over a decade now.

MKB , Aug 19, Occasionally, our PayPal shopping cart will return a shipping cost that is incorrect if you are ordering more than one item. If you are purchasing multiple items from our website, and you believe that the shipping charge may be incorrect, please email us, and we will check it and get back to you with a correct shipping amount on a package deal immediately- thanks!

With the ever-so-wide quality range of current production tubes, and the "spin the roulette wheel" world of NOS and vintage used tubes, it pays to know how your amplifier is handling those expensive tubes you are putting into it. Simply multiply the outcome by 1, to get. Skip to main content. It is unique in the fact that it shows you both the plate current and plate voltage simultaneously and it is completely self- contained with no switches or batteries.

It is phantom powered using an extremely small amount of the AC voltage and current produced by the amplifier it is being used to test. Simply remove one of your power tubes, install the probe, which indexes exactly like the tube does with the timing key on the guide pin, then install the tube in the top of the probe.

Make sure you have a speaker load connected to the amp and then power the amp up. If your amp has a standby switch leave the amp in standby for about thirty to sixty seconds and then switch to the play mode.

Most all amps will show zero plate current until switched out of standby to the play mode. Unlike other probes the "Pro One" uses a direct plate current reading therefore subtracting the screen current is not necessary. The information below is applicable for push pull adjustable bias amps. All you have to do is make a simple calculation by dividing the dissipation of the tube in watts into the plate voltage and then multiply the result by.

For example, if you were biasing a 25 watt tube and your DC plate voltage was VDC the calculation would look like this. Our recommended procedure: Install the probe under one of your tubes, make sure you have a speaker load on the amp and turn the amp on. If the amp has a standby switch then leave the amp in standby for 30 to 60 seconds, then switch to the play mode.

Adjust the bias to between 20 to 25mA which is a conservative setting for most all amps while you note the DC plate voltage and use the formula above to calculate the bias you want. If your calculated bias point happens to be 40mA then adjust the bias current up. You will notice that as the current is adjusted up the DC plate voltage will drop slightly, but the difference upon recalculation will be insignificant.