DIY JE-990 DOA

[jdbakker]

Digi-Key have them in various SMD sizes; the 91p is even stocked in thru-hole.

I am going to place an order with them before the end of the year, and wouldn't mind getting a few extra parts for .nl/.eu forum members. PM me if you want me to get some for you. I will likely get 0805s for both parts.

JDB.
[I <heart> Digi-Key. Now if only UPS and Customs could figure out where they've left my last Digi order...]

 

[mnats]

I posted earlier that I had updated the files linked from my 990 page but I forgot to update the links themselves. Here are the direct links to the corrected documentation and the corrected Gerber files with the silkscreen layer and new inductor footprints. Thanks to all who found the errors.

 

[radiance]

Thanks!

 

[evm1024]

I have a few ceramic disc 62 pf caps but the leads are just too far apart. In the end I got a bunch of 62 pf COG SMD caps and soldered them on the back of the board.

Here are 8 DOA ready to test....just gotta find the time.

Ethan

 

[sbranco]

OK so I was waiting around for someone to do this for me and I thought maybe someone else might benefit from this.

I would be careful to check over these parts and make sure they work for you. This was the best I could come up with for the non ptown kid parts needed for these DIY 990 DOA's. (I am no electrical engineer, so double check the parts!)

I am figuring on stripping the solid copper out of some cat-5 cable or similar for the inductors. didn't make sense to buy a $42 spool of wire just for that.

Here is a link to an excel spreadsheet with links to the mouser parts.

http://hosted.filefront.com/sbranco/


MOUSER - Non Ptown Kid Parts List for DIY Jensen 990 DOA x 8 kits
Mouser Mfr.'s Manufacturer Order Availability* Price Ext.
Part # Part # Description Qty.
Your Part #
512-1N4148TR 1N4148TR Fairchild Diodes - Small Signal 100 Ships Now $0.02 $2.00
DO-35 Hi Conductance Fast - RoHS: COMPLIANT

660-MF1/4DC30R1F MF1/4DC30R1F KOA Speer 1/4Watt Metal Film Resistors 20 Ships Now $0.03 $0.60
30.1ohms 1% 100PPM 1000 PCS BULK - RoHS: COMPLIANT

271-162-RC 271-162-RC Xicon 1/4W 1% Metal Film Resistors 10 Ships Now $0.09 $0.90
162ohms 1% 50PPM - RoHS: COMPLIANT

71-CCF07-G-300 CCF07300RGKR36 Vishay/Dale 1/4WATT Metal Film Resistors 30 Ships Now $0.05 $1.50
1/4WATT 300OHMS 2% Rated to 1/2Watt

660-MF1/4DC2001F MF1/4DC2001F KOA Speer 1/4Watt Metal Film Resistors 10 Ships Now $0.03 $0.30
2Kohms 1% 100PPM 1000 PCS BULK - RoHS: COMPLIANT

271-180-RC 271-180-RC Xicon 1/4W 1% Metal Film Resistors 10 Ships Now $0.09 $0.90
180ohms 1% 50PPM - RoHS: COMPLIANT

271-130-RC 271-130-RC Xicon 1/4W 1% Metal Film Resistors 10 Ships Now $0.09 $0.90
130ohms 1% 50PPM - RoHS: COMPLIANT

660-MF1/4DC6192F MF1/4DC6192F KOA Speer 1/4Watt Metal Film Resistors 20 Ships Now $0.03 $0.60
61.9Kohms 1% 100PPM 1000 PCS BULK - RoHS: COMPLIANT

660-MF1/4DL1100F MF1/4DL1100F KOA Speer 1/4Watt Metal Film Resistors 10 Ships Now $0.06 $0.60
110ohms 1% 100PPM 1000 PCS BULK - RoHS: non-compliant/CONTAINS Pb

299-3.9-RC 299-3.9-RC Xicon 1/8W 5% Carbon Film Resistors 20 Ships Now $0.05 $1.00
3.9ohms 5% - RoHS: COMPLIANT

80-C322C151J2G C322C151J2G5TA Kemet Conformally Coated Radial Ceramic Capacitors 10 Ships Now $0.34 $3.40
200V C0G 150pF 5% - RoHS: COMPLIANT

80-C317C680K2G5HA C317C680K2G5HA Kemet Conformally Coated Radial Ceramic Capacitors 15 Ships Now $0.22 $3.30
200V C0G 68pF Contains Lead - RoHS: non-compliant/CONTAINS Pb

81-RPE5C2A910J2P1Z03 RPE5C2A910J2P1Z03B Murata Monolithic Radial Lead Capacitors 10 Ships Now $0.26 $2.60
91pF, 100volts, C0G - RoHS: COMPLIANT

81-RPER71H104K2P1A03 RPER71H104K2P1A03B Murata Monolithic Radial Lead Capacitors 20 Ships Now $0.29 $5.80
100000pF 50volts X7R - RoHS: COMPLIANT

Sub Total: $24.40

 

[gar381]

30 ga. wire at your local Radio Trash store.

http://www.radioshack.com/product/index.jsp?productId=2036277&cp=2032058.2032227.2032240&allCount=5&fbn=Cable+Type%2FMagnet&f=PAD%2FCable+Type%2FMagnet&fbc=1&parentPage=family

Model: 278-1345 $4.99usd

GARY

 

[sbranco]

Hey thanks Gary. Nice. I am Rat Shack bound!

 

[imo]

still wondering if anyone has found a reasonable, preferably stateside, source for the LM394BH. The cheapest i can find them is around $9..National doesn't seem to be doing any samples. Does anyone have any extras they want to sell, or possibly a small group buy to knock the cost down?
Ian

 

[Sender]

A couple of real quick questions......


1. On page 2 of the PDF, there is a bill of materials, and listed there is a Q10, however I don't see Q10 on the layout. Was this dumped in a revision?

2. In the notes, is also says that "CR3 is a diode-connected transistor as per Jensen". Can someone go into more details on this? The schematic shows it as a 4250, so how is it different?

 

[Ptownkid]

CR3 is Q10 and Q10 is CR3

I ran into the same problem, but if you look closely at the schematic...

 

[dissonantstring]

hi sender,
(ptown beat me to the punch! :thumb: )
i believe that Q10 is the transistor thermally coupled with Q3 on the layout/overlay image in mnats DIY JE-990 doc (the one that has the CR3 designation on the left of it). face the flats of the two transistors (Q3 and Q10) together, slap some heatsink compound between 'em and put some heatshrink tubing around both to keep them together. CR3 (the diode connected transistor was originally a 1N914B diode), but mako replaced it with Q10 - can't remember the reason though .
regards,
grant

 

[Sender]

Cool thanks guys!

Also, ptown, how do I read the values of the caps? My meter only goes down to pf so I can't test them.

Thanks a bunch!

 

[Ptownkid]

If it goes down to pF you should be able to read them...

Either way, *most* caps are labled like trim pots

103 for example means 10 and 3 more zeros, which is 10,000 of the smallest unit, in the case of caps, it's pF. 10,000pF = 10nF = .01uF etc

does that make sense?

 

[kazper]

I know this is a sort of dumb question but is there a correct way to place the pins on the PCB. is it through the whole or is it from the bottom.

Maby one of you smart picture types can help me out. I'm building them from Ptowns kits.

 

[Nele]

I've actually wondered about the same thing. After trying both ways I ended up putting them through the hole from the top.

Cheers,
Corneel

 

[Ptownkid]

I've always put them in from the bottom...but whatever works

 

[sbranco]

Built two doa's from the parts list posted before. Though I used 62K resistors for R10 and R11 which are supposed to be for 24V, I supplied 18V and it appears to work fine. If you plan on 18V use 42.2K resistors, for 15V - 33.2K and 12V - 28K.

One doa worked and one did not. Fried R7 on the one that did not work. Got the Rat Shack magnet wire in 3 guages. Its difficult to get the 30 guage in there so we used the smallest 22 guage. MISTAKE. I am going back and replace it with the 30 guage. If the wire is not pulled tight and there is too much play between the inductor and the board, I think they may have shorted causing the fried R7 and lots of noise you don't want to hear. Its difficult but possible to get the 30 guage wire in there. Even the 26 guage would have been better. And if using smaller guage, mount the inductors close enough to the baord to prevent a short. (duh!)

 

[Sender]

[quote author="Ptownkid"]If it goes down to pF you should be able to read them...

Either way, *most* caps are labled like trim pots

103 for example means 10 and 3 more zeros, which is 10,000 of the smallest unit, in the case of caps, it's pF. 10,000pF = 10nF = .01uF etc

does that make sense?[/quote]

Thanks ptown, I meant to say my meter only goes to nf.

 

[Ptownkid]

[quote author="sbranco"] If the wire is not pulled tight and there is too much play between the inductor and the board, I think they may have shorted causing the fried R7[/quote]

What shorted? I have one with the same problem, fried R7

 

[sbranco]

Note that I could be totally wrong because I have not changed the inductors yet and I am acquiring electronic knowledge VERY SLOWLY.

My buddy and I soldered two of these at the same time in the same manner. A couple of parts he did on both. The one I soldered worked.

If I remember correctly, which is not assured, then the one that did not work passed no signal but emitted the most distasteful feedback screeching before R7 fried and it went silent.

The working doa emits a similar screeching when I touch one of the inductors. The non-working inductors do not appear to be threaded quite as tightly on the bottom. But you know what? now that I am writing this, how can the inductor which has only one wire short to itself? Well, what do I know. I am going to thread the heavier guage wire in there anyway and if that was not the problem, on to my next brilliant theory.

If you figure out what happened to R7 before me, put me out of my electronics misery and let me know! Maybe someone else has also fried R7 or knows why it would?