! Standby alert !
“There are four lights!”
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb!
Looking forward to summer in Somerset later in the year :)
Great links, Mark! Cheers!
Replacing TR1/TR2 on an Issue 2 sounds interesting. I just wonder whether the letter at the end makes a difference (BC548B/C resp. B549B/C)?
Great links, Mark! Cheers!
Replacing TR1/TR2 on an Issue 2 sounds interesting. I just wonder whether the letter at the end makes a difference (BC548B/C resp. B549B/C)?
The letter at the end indicates the gain group. The manufacturer tests the transistors and groups them in to a gain group. For the BC547 / BC548 / BC549 series (plus many others) devices with a "A" suffix have the lowest gain, devices with a "C" suffix have the highest gain.
In most applications (and indeed all well designed circuits), you should be able to replace a low gain group transistor with a higher gain group transistor.
The BC547 / BC548 / BC549 series are equivalents for each other in most applications.They are general purpose small signal NPN transistors.
! Standby alert !
“There are four lights!”
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb!
Looking forward to summer in Somerset later in the year :)
One thing to watch out for if substituting an "equivalent" transistor, is to check the pin-out.
Normally the data sheet (or data book) will show the lead-out as viewed from below (unlike chips which are viewed from above).
The transistor may need to be orientated differently to the outline on the PCB, and different to the transistor that it replaces.
! Standby alert !
“There are four lights!”
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb!
Looking forward to summer in Somerset later in the year :)
Comments
schombi.de/my-retro-collection.html"
An old post gives lots of other replacements, don't have the link to hand at the moment.
May be back when I have found it :razz:
Edit: have a look at these three links:-
http://www.worldofspectrum.org/forums/showthread.php?t=14018
http://www.worldofspectrum.org/forums/showthread.php?t=14234
http://www.zxshed.co.uk/sinclairfaq/index.php5?title=Replacement_Components
Mark
Repair Guides. Spanish Hardware site.
WoS - can't download? Info here...
former Meulie Spectrum Archive but no longer available :-(
Spectranet: the TNFS directory thread
! Standby alert !
“There are four lights!”
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb!
Looking forward to summer in Somerset later in the year :)
Replacing TR1/TR2 on an Issue 2 sounds interesting. I just wonder whether the letter at the end makes a difference (BC548B/C resp. B549B/C)?
schombi.de/my-retro-collection.html"
The letter at the end indicates the gain group. The manufacturer tests the transistors and groups them in to a gain group. For the BC547 / BC548 / BC549 series (plus many others) devices with a "A" suffix have the lowest gain, devices with a "C" suffix have the highest gain.
In most applications (and indeed all well designed circuits), you should be able to replace a low gain group transistor with a higher gain group transistor.
The BC547 / BC548 / BC549 series are equivalents for each other in most applications.They are general purpose small signal NPN transistors.
Mark
Repair Guides. Spanish Hardware site.
WoS - can't download? Info here...
former Meulie Spectrum Archive but no longer available :-(
Spectranet: the TNFS directory thread
! Standby alert !
“There are four lights!”
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb!
Looking forward to summer in Somerset later in the year :)
Normally the data sheet (or data book) will show the lead-out as viewed from below (unlike chips which are viewed from above).
The transistor may need to be orientated differently to the outline on the PCB, and different to the transistor that it replaces.
Mark
Repair Guides. Spanish Hardware site.
WoS - can't download? Info here...
former Meulie Spectrum Archive but no longer available :-(
Spectranet: the TNFS directory thread
! Standby alert !
“There are four lights!”
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb!
Looking forward to summer in Somerset later in the year :)
Just found that Pollin (www.pollin.de) has e.g. BC549, BC557, BC238, BC550 for 30-40 ct per ten pieces. Bargain!
schombi.de/my-retro-collection.html"
as well as Kessler-Electronic (http://www.kessler-electronic.de/Halbleiter/Transistoren/BC/BC__Plastikgehaeuse_c451.htm - mostly about 36 ct per 10 pieces
Also - for example - Lithium cells are there: http://www.kessler-electronic.de/Batterien_und_Akkus/Knopfzellen/Lithium-Knopfzellen/Varta_lose/CR2032_i951_22910_0.htm
Greets Ingo.