Air brake problems

[bkorthals]

I am having issues with my air brake. It works but it seems that there is no controlling the attenuation. It is just very very quiet on all settings. Any suggestions?

[bkorthals]

Here are some pics.

[M Fowler]

bkorthals,

Shouldn't the two wires going to the center of the Lorling Rotary switch be reversed?

I checked all other wires and it looks good otherwise. The half of the switch for sector 1 to 5 should go to right side of 100 watt resistor and the other sector 7 to 10 go to tip of speaker jack.

Mark

[M Fowler]

Never mind you have it right. It should work just the way you have it wired. The sliding lugs are not touching the chassis right? I did that and rewired the whole darn thing twice before I knew it. But yours looks like it is elevated off the chassis in pictures.

Mark

[stubbyfex]

Hello!
I just finished mine a few days ago. I had no output also. Then I took my ohm meter and hooked it between the input jack "hot" and the output jack "hot", and rotated the switch. The meter showed open, or infinity. I finally tracked the problem down to the variable resistor. I had to sand the "coil" of resistance wire to get the sliders to make contact. I used a fine file, and it took quite a bit of filling too. After doing it, the wires were quite bright looking as opposed to the dark color before I started. I also used 1/4" non insulated press on female quick connects to hook the wires up to the sliders.
Now it works and sounds fine. There is just a small amount of loss of highs when it is in use. I can compensate by turning the treble pot up about one number.

[M Fowler]

Yeah it seems we should warm new builders to sand lightly on the variable resistors and lugs to get good contact as this has been a problem lately.

Mark

[angelodp]

Yes indeed, I had to sand mine as well. I checked it before installing, and it works fine.

ange

[BDC]

+1 on the sanding.......

[redshark]

Yes I just finished mine and it probably needs to be sanded to make better contact. What do you guys use to lightly sand the resistor?
Mine has another little problem, when I am on the bedroom settings and I get close to the air brake to change the bedroom volumes it squeals a little and then once I get away from it the unit is quiet again. I though that was only gonna happen with the express but it did the same when playing my JTM45 clone as well.

[BDC]

20 grit sand paper or finer should work fine-or a fairly equivelant file..

[Structo]

20 grit is way too coarse. (not even sure they make it)
Maybe you meant 200?

[danotron]

Make sure your switch isn't buggered from applying too much heat while soldering...its easy to do......

And 320 grit sand paper.....