Search found 218 matches

by k7elp60
Sat Dec 15, 2012 3:37 pm
Forum: General Discussion
Topic: LM386 Bass Boost Question
Replies: 7
Views: 1437

Re: LM386 Bass Boost Question

I have about 100 or more .033uF film capacitors. They are rectangle shaped 0.5" by 0.15" by .35 and have 1/2 inch leads. I would be happy to send you a bunch.
Ned
by k7elp60
Wed May 23, 2012 4:44 pm
Forum: General Discussion
Topic: Looking for a special selector switch...
Replies: 7
Views: 1321

Re: Looking for a special selector switch...

I would add a fuse in each + lead of the batteries, and every connection to that terminal is after the fuse. The reason is that the short current current can be many times the load current and it can make connecting wires red hot. I speak from experience. I once did a circuit that connected two 6V b...
by k7elp60
Wed Mar 21, 2012 11:22 am
Forum: General Discussion
Topic: need help , i am searching for a project box..
Replies: 2
Views: 701

Re: need help , i am searching for a project box..

How about a PacTec# HP-9VB.
I have on that is new in original package and the dimensions are about exactly as you wanted. Mouser lists them at abour $7.50 U.S. Dollars.
If you live in the US I will mail you this one for $8.00 includes postage.
Ned
by k7elp60
Tue Dec 06, 2011 8:24 am
Forum: General Discussion
Topic: 556 timer help...
Replies: 11
Views: 2328

Re: 556 timer help...

Here is a direct link to the schematic.
http://s1030.photobucket.com/albums/y365/k7elp601/
by k7elp60
Mon Dec 05, 2011 5:52 am
Forum: General Discussion
Topic: 556 timer help...
Replies: 11
Views: 2328

Re: 556 timer help...

I used to build tens units. I see if I can find the schematic. It used a 556, both of them were configured as astable MV's. The first MV drove a 2N3904 to drive a 2N2222. A pot to control drive. The 2N2222 drove a 1k/8ohm transformer in reverse to control the output voltage. As I recall the voltage ...
by k7elp60
Sun Apr 03, 2011 6:21 am
Forum: General Discussion
Topic: Inductors for Receiver
Replies: 14
Views: 2843

Re: Inductors for Receiver

I think 10mH is way to high in inductance. I have built a number of AM broadcast band receivers and about 250uH is good for about 550Khz. I use a formula that is from the formula for calculating resonate frequency of a LC tank. The formula is LC= 25330/(f x f) where L is in uH, C is in pf and f is i...
by k7elp60
Sat Nov 13, 2010 8:16 am
Forum: General Discussion
Topic: LED Christmas lighting strings.....
Replies: 18
Views: 3134

Re: LED Christmas lighting strings.....

I have been using some 2pin connectors for quite sometime to make my own light strings. They are MTA100 connectors by TYCO. The ones I use are Digikey P/N A30833-ND. They are idc connectors so it takes a special tool to press the wire into the contacts, but they hold T1 and T1 3/4 LED's real snug. T...
by k7elp60
Tue Aug 24, 2010 5:33 pm
Forum: General Discussion
Topic: OT: Personal Project - Dr. Pepper Machine Rebuild!
Replies: 5
Views: 1076

Re: OT: Personal Project - Dr. Pepper Machine Rebuild!

As I remember a long time ago Dr. Pepper was really carbonated prune juice. I remember when it was dispensed in light green colored bottles, and had some times or numbers on the bottles. Boy has it changed.............but I still like it.
Ned
by k7elp60
Mon Jun 07, 2010 5:53 pm
Forum: General Discussion
Topic: Extracting only the available power...
Replies: 5
Views: 924

Re: Extracting only the available power...

My thoughts are very close to MrAl's. That is to control the current of a regulated voltage charger.
by k7elp60
Wed Apr 14, 2010 1:51 pm
Forum: General Discussion
Topic: Tube Question, Ancient Technology.
Replies: 9
Views: 1180

Re: Tube Question, Ancient Technology.

Bob, When I started out in electronics (early 1950's) I built a lot of stuff with tubes, and I remember a few things. The tetrode(cathode, control grid, screen grid, and plate) was interesting as the screen grid(closest to the plate) could control the electron flow dramatically. Since it was normall...
by k7elp60
Sat Mar 27, 2010 11:42 am
Forum: General Discussion
Topic: cookbook search - RCA - CA3161E - CA3162E combo.
Replies: 13
Views: 1670

Re: cookbook search - RCA - CA3161E - CA3162E combo.

hi again, i found something that might be of use to me,,if anyone happens to have any old copys of "Radio Electronics" magazines specificially JULY 1990 i seen a partial article about digital dashboard, and it uses a lot of the ic's i mentioned in this thread.. but pages 32 & 34 are missing. my oth...
by k7elp60
Sat Feb 13, 2010 1:06 pm
Forum: General Discussion
Topic: lm3919?
Replies: 40
Views: 3773

Re: lm3919?

I have 1982 National data book. It lists the LM3909 and LM3914 thru LM3916 but no 3919, it does list a LM3999, which is a precision Reference. So no help here.
by k7elp60
Sun Jan 10, 2010 3:19 pm
Forum: General Discussion
Topic: Help to build a Ion Detector, please....
Replies: 7
Views: 2245

Re: Help to build a Ion Detector, please....

If I add other three transistor with the polarity reversed ,in a parallel path on the circuit ,have you any idea were to connect the DPDT switch to change the sensing of ions? Q3 have to be reversed,also? IF you are asking me, I am afraid I can't help you with the connections of the DPDT switch. If...
by k7elp60
Sun Jan 10, 2010 8:10 am
Forum: General Discussion
Topic: Help to build a Ion Detector, please....
Replies: 7
Views: 2245

Re: Help to build a Ion Detector, please....

Looking at the schematic I see a number of issues. 1. The PN2222 is drawn as a PNP when in fact the PN2222 is a NPN transistor. 2. The Polarity of the battery for the PN2907 transistors is incorrect. There is no current limiting resistor for the LED. Aside from this I would use the 100 microamp mete...
by k7elp60
Sun Jan 03, 2010 6:43 pm
Forum: General Discussion
Topic: Which DC outlet would you use ?
Replies: 9
Views: 1286

Re: Which DC outlet would you use ?

I have had good luck with Anderson power pole connectors. Here is a websit:http://www.powerwerx.com/anderson-powerpoles/ A lot of Hams use them for there 12V radio's and power. The small ones have eiither 15A or 30A contacts. I have mounted them in normal electrical outlet blank plates, as well as o...