found this seller n ebay selling dca55 semiconductor analisers for reasonable prices $82.50 plus $5.80 shipping...I paid $136 for mine a while ago. they have several for sale. this is a powerful tool for the pedal builder especially one who likes building with ge transistors. here's the link
http://www.ebay.com/itm/Atlas-DCA55-Semiconductor-Tester-/181171327054?pt=LH_DefaultDomain_0&hash=item2a2ea7104e (http://www.ebay.com/itm/Atlas-DCA55-Semiconductor-Tester-/181171327054?pt=LH_DefaultDomain_0&hash=item2a2ea7104e)
Quote from: jimijam on November 06, 2013, 03:13:05 PM
found this seller n ebay selling dca55 semiconductor analisers for reasonable prices $82.50 plus $5.80 shipping...I paid $136 for mine a while ago. they have several for sale. this is a powerful tool for the pedal builder especially one who likes building with ge transistors. here's the link
http://www.ebay.com/itm/Atlas-DCA55-Semiconductor-Tester-/181171327054?pt=LH_DefaultDomain_0&hash=item2a2ea7104e (http://www.ebay.com/itm/Atlas-DCA55-Semiconductor-Tester-/181171327054?pt=LH_DefaultDomain_0&hash=item2a2ea7104e)
Did you get they DCA55 or DCA75 for $136. The DCA75 is more expensive, but I think it's worth it for the extra features.
Quote from: pickdropper on November 06, 2013, 04:19:27 PM
Quote from: jimijam on November 06, 2013, 03:13:05 PM
found this seller n ebay selling dca55 semiconductor analisers for reasonable prices $82.50 plus $5.80 shipping...I paid $136 for mine a while ago. they have several for sale. this is a powerful tool for the pedal builder especially one who likes building with ge transistors. here's the link
http://www.ebay.com/itm/Atlas-DCA55-Semiconductor-Tester-/181171327054?pt=LH_DefaultDomain_0&hash=item2a2ea7104e (http://www.ebay.com/itm/Atlas-DCA55-Semiconductor-Tester-/181171327054?pt=LH_DefaultDomain_0&hash=item2a2ea7104e)
Did you get they DCA55 or DCA75 for $136. The DCA75 is more expensive, but I think it's worth it for the extra features.
I have the DCA75 and it is cool. If you sell a lot of transistors I found having the USB connection pretty cool since you can do a reading of a transistor and save all the info/graphs and post them with the transistors for sale.
I bought a auction lot of transistors and I was able to test and sort really fast with this unit.
Next I am going to pick up the LCR40 Passive Electronics next.
I had a question for you guys with the DCA's and testing germaniums. Since germanium properties change with temp, how does the atlas compensate for this? Do you plug it in and wait 10 mins then take a reading?
Edit: Or just don't touch it!
Cheers,
Paul
I have a question too. Can you use these to match Jfets?
Quote from: chromesphere on November 06, 2013, 11:29:01 PM
I had a question for you guys with the DCA's and testing germaniums. Since germanium properties change with temp, how does the atlas compensate for this? Do you plug it in and wait 10 mins then take a reading?
Edit: Or just don't touch it!
Cheers,
Paul
I just don't handle them much. You can also hook up the leads and then take 3 or 4 reading and compare. But I have never seen it skew to much with momentary handling. I usually handle by the leads.
Hope this helps.
So I tested a AC128 since I had them with in arms length. I took one reading without touching anything except the leads
Test Result:
PNP Germanium BJT
Red-B Green-E Blue-C
HFE=121 at Ic=5.02mA
Vbe=0.222V at Ib=5.01mA
IcLeak=0.381mA
(http://music.codydeschenes.com/wp-content/uploads/2013/11/001.png)
This next reading I took with holding the metal can in my closed hand. I held it like the grenade was held in the air vent in Aliens. Here is what I got with the same test.
Test Result:
PNP Germanium BJT
Red-B Green-E Blue-C
HFE=134 at Ic=5.04mA
Vbe=0.215V at Ib=5.00mA
IcLeak=0.731mA
(http://music.codydeschenes.com/wp-content/uploads/2013/11/002.png)
Hope this helps.
Quote from: billstein on November 07, 2013, 12:39:44 AM
I have a question too. Can you use these to match Jfets?
You can with the DCA-75, but I don't believe you can with the DCA-55. The DCA-55 does not measure the pinch-off voltage. On Peak's site, it does list JFET compatibiity, bu apparently it is limited. Maybe somebody who owns the DCA-55 can chime in.
http://www.peakelec.co.uk/acatalog/dca75-dca-pro.html
I've got a 55, it doesn't handle JFETs at all really, just identifies as a JFET, and can only identify the gate.
Quote from: selfdestroyer on November 07, 2013, 07:23:27 AM
So I tested a AC128 since I had them with in arms length. I took one reading without touching anything except the leads
Test Result:
PNP Germanium BJT
Red-B Green-E Blue-C
HFE=121 at Ic=5.02mA
Vbe=0.222V at Ib=5.01mA
IcLeak=0.381mA
(http://music.codydeschenes.com/wp-content/uploads/2013/11/001.png)
This next reading I took with holding the metal can in my closed hand. I held it like the grenade was held in the air vent in Aliens. Here is what I got with the same test.
Test Result:
PNP Germanium BJT
Red-B Green-E Blue-C
HFE=134 at Ic=5.04mA
Vbe=0.215V at Ib=5.00mA
IcLeak=0.731mA
(http://music.codydeschenes.com/wp-content/uploads/2013/11/002.png)
Hope this helps.
Very much so! Thank you I think I will have to put in an early xmas present order :D
Paul