Search found 218 matches
- Sun Jan 13, 2008 7:01 pm
- Forum: General Discussion
- Topic: Need a simple circuit for detecting a TTL-level square wave
- Replies: 7
- Views: 4320
Re: Need a simple circuit for detecting a TTL-level square w
[quote=" Ideally, I would love to use some kind of integrated circuit that is designed to detect square waves/clock signals and produces a "1" when it detects it. But I haven't been able find a chip that would do this. Once I find a solution to this problem, I plan on publishing an ar...
- Sat Jan 05, 2008 8:26 pm
- Forum: General Discussion
- Topic: Judging battery life
- Replies: 5
- Views: 3099
- Tue Jan 01, 2008 5:43 pm
- Forum: General Discussion
- Topic: 12 volt rechargeable battery
- Replies: 5
- Views: 3716
There are a couple of places that I know about that will custom make your rechargeable battery. They will spot weld the terminals,encase the pack in heatshrink wrap,supply it with pigtail leads or a connector. They are www.standardsupply.com and www.car-gobattery.com There are even 12V gel-cell batt...
- Sun Dec 09, 2007 4:45 pm
- Forum: General Discussion
- Topic: patch cord supplier
- Replies: 6
- Views: 3443
Dave,
Not sure if this will help you, but Caltronics in their on line catalogue has some 2' ones. Here is the link http://www.caltronix.com/
Ned
Not sure if this will help you, but Caltronics in their on line catalogue has some 2' ones. Here is the link http://www.caltronix.com/
Ned
- Fri Nov 23, 2007 2:30 pm
- Forum: Up For Grabs
- Topic: LA2730 Dolby B-type noise reduction system
- Replies: 3
- Views: 5239
LA2730 Dolby B-type noise reduction system
I have 3 ea of these IC's I have no use for. Yours for free.
Ned
P.S. I was unable to find a complete data sheet for them.
Ned
P.S. I was unable to find a complete data sheet for them.
- Sun Nov 18, 2007 8:11 am
- Forum: General Discussion
- Topic: Very small 2mm dc power plug, where to get?
- Replies: 4
- Views: 2573
Hello Mr. Al, I had a similar problem about a month ago. I normally order from Mouser, so I looked in their catalogue and ordered what I thought was the right one. When it arrived it wasn't the right size. I live in an area where the only place that has electronics parts locallly is Radio Shack. I w...
- Thu Sep 20, 2007 1:05 pm
- Forum: General Discussion
- Topic: Anyone else here charge/test batteries quite often?
- Replies: 12
- Views: 5932
- Wed Sep 19, 2007 7:09 pm
- Forum: General Discussion
- Topic: Anyone else here charge/test batteries quite often?
- Replies: 12
- Views: 5932
Mr Al, I have been doing testing, and building chargers for NiCad NiMH and Lead-Acid batteries for quite a number of years. I wrote a series of articles once for an amateur radio news letter about 8 years ago. I have copies of the complete newsletter in PDF format that I would be glad to share with ...
- Mon Aug 27, 2007 8:17 pm
- Forum: General Discussion
- Topic: Ion deflection plate switch
- Replies: 2
- Views: 2066
- Tue Jun 19, 2007 6:39 pm
- Forum: General Discussion
- Topic: Underground electrical signalling ?
- Replies: 13
- Views: 5808
I once built a device that measured the impedance between two metal poles driven into the earth. This was part of a project to inject audio frequencies into the earth via the two metal stakes. A digital audio generator fed a audio amplifier of about 20 watts. The output of the amplifier was about 8 ...
- Sat Jun 02, 2007 6:20 am
- Forum: General Discussion
- Topic: crystal radio using vacuum tube diode
- Replies: 12
- Views: 7335
If memory serves me right, the 6AL5 filament requires 150 ma. A simple task for the right wallwart (6V @ .15 A), The filament voltage dosn't have to be to precise - +/- 10% will do fine. These tubes were used in millions of receivers as AM detectors and FM Foster-Seely discriminators (FM detector)....
- Fri Jun 01, 2007 5:54 pm
- Forum: General Discussion
- Topic: crystal radio using vacuum tube diode
- Replies: 12
- Views: 7335
I think it is possible to do the circuit with out a 6.3V transformer. I remember doing something similar a long time a go. What I did was put a regular 120V lamp bulb in series with the vacuum tube filament. It took a long time for the tube to light but it worked. I just did the math and 36 watt bul...
- Wed May 30, 2007 1:49 pm
- Forum: General Discussion
- Topic: Ferrite antenna on AM receiver...
- Replies: 2
- Views: 2001
I have two books that have information on ferrite-core antennas, one is the ARRL antenna book and the other one is exploring RF Circuits by Joseph Carr. The both indicate that type of antenna for the am broadcast band is directional in the horizontal position. In the case of the ferrite core antenna...
- Sat May 19, 2007 7:06 pm
- Forum: General Discussion
- Topic: Obsolete Equipment Manuals
- Replies: 4
- Views: 2813
Robert here is a list of sites I have. I haven't been to any of them in a while so I don't know how current they are. http://www.tech-systems-labs.com/ http://www.arireggioemilia.org/download/Manuali%20Radio/ http://www.wb4hfn.com/DRAKE/DrakeManuals.htm http://www.hamdirectory.info/icom.html http://...
- Tue Apr 10, 2007 3:26 pm
- Forum: General Discussion
- Topic: The impending death of incandescent bulbs
- Replies: 100
- Views: 78662
My two cents worth. I don't like the fluorescent or LEDs lighting, especially as for reading lights. I think they are a poor substitue for the incandescent bulb. I have some solar panels to charge batteries for my amateur radio station equipment. I went one step further and installed some RV light f...