15 meg resistor

[timmy]

When is a 15 meg ohm resistor to high in value? I have a 15 meg that measures alittle over 17meg.

[Electronic M]

What's the tolerance rating? It should be listed on the part, in the Sam's schematic or the Sam's parts list....If Sam's doesn't list tolerance assume 10%.

[old_coot88]

What kind of circuit is it used in?

[stuben]

If there are only three color bands on the resistor then the tolerance is 20% in which case you are okay. If there is a fourth color band it will be either silver,(10%) or gold (5%)

[old_coot88]

The type of circuit it's used in determines what tolerance value is required. I.e., a focus divider circuit would need very tight tolerance, a simple grid leak resistor on an audio tube would be a hugely-wide tolerance.

[timmy]

Ok the resistor is not an issue but why or is it normal for a to92 pnp transistor to show continuity if you put negative probe on center and probe each outside leads with the positive in diode check? ? I have new nte ones and they do it also. The transistor is a bf506 and I have an equivalent nte159 but yet the nte don’t seem to work.

[zeno]

Originally Posted by timmy

Ok the resistor is not an issue but why or is it normal for a to92 pnp transistor to show continuity if you put negative probe on center and probe each outside leads with the positive in diode check? ? I have new nte ones and they do it also. The transistor is a bf506 and I have an equivalent nte159 but yet the nte don’t seem to work.

Test by lifting the E & C. Do not touch the wires with your hands.
Use the base as common. One way you should get @ .7 v the other open.
Check E-C also, should read open.

Zeno

[timmy]

Originally Posted by zeno

Test by lifting the E & C. Do not touch the wires with your hands.
Use the base as common. One way you should get @ .7 v the other open.
Check E-C also, should read open.

Zeno

that’s what thought all pnp transistors seem to do this but I found out why they didn’t work because they had to be turned around the originals were from the uk so of course nothing will work so I’m turning them around tomorrow and hope for the best.

[zeno]

Originally Posted by timmy

that’s what thought all pnp transistors seem to do this but I found out why they didn’t work because they had to be turned around the originals were from the uk so of course nothing will work so I’m turning them around tomorrow and hope for the best.

Yes you do have to watch the basing especially on subs. Exceptions to test
are big power transistors like HOT's & audio amp outputs. They almost always dead short. Modern HOT's usually have a diode & resistor built in. That
makes the readings screwy. Not to worry, they dead short anyways.
Older germanium transistors can show odd numbers & the B-E & B-C
will show @ .2 on meter.

[timmy]

I have 2 transistors one is supposed to be a direct replacement which is a nte159 to replace a br506 so the 506 voltage rating is -35 and -40 the nte is -80 and -80 so does this big voltage difference affect it working or not because of this difference. Operating voltage I believe is 33volts. And what is the 3 color stripes on the back of a to92 transistor and to92 diode.

[Yamamaya42]

nte159 is a generic part and may or may not work, IF you can find a real one, many fake parts out there, always best to get a REAL original bf506 transistor, if you can find one.

[timmy]

Originally Posted by Yamamaya42

nte159 is a generic part and may or may not work, IF you can find a real one, many fake parts out there, always best to get a REAL original bf506 transistor, if you can find one.

Here’s the problem the 506 and 509 are for vhf circuit and the only place to get them is Germany but nte says they can go in place of both.

[Yamamaya42]

Originally Posted by timmy

Here’s the problem the 506 and 509 are for vhf circuit and the only place to get them is Germany but nte says they can go in place of both.

if the NTE is from a reputable source, chances are it will work, if put in the right way. but, that's the trick!

[timmy]

Originally Posted by Yamamaya42

if the NTE is from a reputable source, chances are it will work, if put in the right way. but, that's the trick!

I got them on line in an nte package and checked out the pin out between the both nte and the 506 and 509 the pin out was ebc turned to cbe

[Yamamaya42]

That is not unusual when using a generic transistor like that, you often have to re-arrange the pins on the new one to get it to match up.