Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5

B&K RF Signal Generator Repair
#8

OK.

Do you know how to check a transistor?

If not, here's how:

1. Take an ANALOG Ohmmeter.
2. Set it to Ohms, x1 range.
3.
For an NPN transistor:
Put a positive lead to the base, and touch the emitter and collector with the negative. It should conduct. Reverse the leads. Do the same. There should be no conductivity at all. Any conductivity means leakage and the transistor is bad.
For a PNP transistor: same procedure, only leads are reversed. Negative to the base conducts, positive - does not.
4. For any transistor: put one lead to emitter and another to collector. There should be no conductivity. Reverse leads, same thing.

Transistors rarely lose their H21E (Beta) so as long as the integrity test above is good, your transistor is good.

Now that you know that:

Take your schematic, and start checking transistors starting from Q3 and back.


Question: do you have a scope?

PS> Eric, I can guide you through it, but you need to have a basic equipment. A scope would make it easy.


Messages In This Thread
B&K RF Signal Generator Repair - by Eric Adams - 05-09-2013, 06:53 PM
RE: B&K RF Signal Generator Repair - by morzh - 05-09-2013, 07:03 PM
RE: B&K RF Signal Generator Repair - by morzh - 05-09-2013, 08:11 PM
RE: B&K RF Signal Generator Repair - by morzh - 05-10-2013, 08:00 AM
RE: B&K RF Signal Generator Repair - by morzh - 05-10-2013, 01:56 PM
RE: B&K RF Signal Generator Repair - by morzh - 05-10-2013, 07:35 PM
RE: B&K RF Signal Generator Repair - by morzh - 05-10-2013, 07:37 PM
RE: B&K RF Signal Generator Repair - by Arran - 05-10-2013, 08:10 PM
RE: B&K RF Signal Generator Repair - by morzh - 05-11-2013, 06:36 PM
RE: B&K RF Signal Generator Repair - by morzh - 05-11-2013, 08:15 PM
RE: B&K RF Signal Generator Repair - by morzh - 05-11-2013, 09:36 PM
RE: B&K RF Signal Generator Repair - by morzh - 05-11-2013, 10:02 PM
RE: B&K RF Signal Generator Repair - by morzh - 05-11-2013, 10:16 PM
RE: B&K RF Signal Generator Repair - by morzh - 05-12-2013, 07:40 PM
RE: B&K RF Signal Generator Repair - by morzh - 05-13-2013, 11:23 AM
RE: B&K RF Signal Generator Repair - by morzh - 05-15-2013, 12:36 PM
RE: B&K RF Signal Generator Repair - by morzh - 05-15-2013, 01:49 PM
RE: B&K RF Signal Generator Repair - by morzh - 05-16-2013, 08:34 AM



Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Philco 91 Speaker Replacement
The spider is glued on the cone and so is the voice coil. I think you can use a cotton swab dipped in acetone and carefu...RodB — 02:42 PM
Restoring Philco 37-604C
Yes I saw that. If I knew, I'd probably try to arrange for getting it myself. But I have just got one. Which does not m...morzh — 01:44 PM
Philco 38-2 Automatic Tuning
When you push the lever, you are supposed to rotate the disk to the desired station. Then the magnetic tuning will acqu...morzh — 01:42 PM
Philco 38-2 Automatic Tuning
I figure out the muting from another picture that helped. Now I need to know how the automatic tuning works. When I push...dconant — 12:11 PM
Philco 91 Speaker Replacement
How would I go about removing the spider from the cone?dconant — 12:04 PM
Philco 38-2 Automatic Tuning
Hello, I am having trouble getting my automatic tuning to stay unmuted. If I play with the tuning handle I can get it to...dconant — 10:51 AM
Does anyone make photofinish replacements?
Here’s the link to the DIY photofinish section of our site: klondike98 — 09:46 AM
Delco car radio Peko vibrator converstion issues
Hi Richard, Thx for posting the schematic.  As I remember as a kid, these were great performers for the time, likely...MrFixr55 — 08:56 AM
Delco car radio Peko vibrator converstion issues
hello mr Fixr, The Electro  Powersupply that I am powering the radio with has a huge choke plus a 10,000ufd electrolyti...radiorich — 10:58 PM
Delco car radio Peko vibrator converstion issues
How about putting a choke in the power supply? The big cap was likely an attempt to stabilize the DC. Kids who cre...MrFixr55 — 09:19 PM

[-]
Who's Online
There are currently no members online.

>