Search found 18 matches

by gmclam
Sat Feb 02, 2008 3:56 pm
Forum: General Discussion
Topic: Some thoughts on terrestrial digital broadcasting...
Replies: 27
Views: 6991

Re: hdtv and digital

Well I can only say that in my opinion (I have been in electronics for 50+ years and have a BSEE) that this whole digital mandate is about copy protection of movies and digital audio etc. Actually that is only a by-product of the situation. What happened is that the terrestrial broadcasters "compla...
by gmclam
Sun Jan 13, 2008 6:32 pm
Forum: General Discussion
Topic: Some thoughts on terrestrial digital broadcasting...
Replies: 27
Views: 6991

I try for band openings every now and again just for the fun. I wonder how this will show up under digital. Has anyone seen this yet? Right now, 1/08, many stations are not transmitting digitally at full power, full antenna height or even on their final channels. Once analog broadcasts are gone and...
by gmclam
Fri Jan 04, 2008 2:41 pm
Forum: General Discussion
Topic: Random Number
Replies: 6
Views: 2271

Random number generation does not have much to do with the type of CPU you're using. You can perform some form of RNG on any CPU. There are a lot of approaches to getting a truly random value, and it works best if you're able to somehow tie that to an "external" event. For example, upon power up the...
by gmclam
Fri Jan 04, 2008 2:33 pm
Forum: General Discussion
Topic: Tapping for audio and video signals...
Replies: 11
Views: 2533

Re: Tapping for audio and video signals...

...Now, how to tap video signal? Is it the contrast potentiometer wiper on a TV the right point? - As to use/adapt as 'video in' to monitor NTSC on a TV , or to get a video output from a TV that has no composite video 'RCA' connectors-... There is really 2 separate questions here. The first is wher...
by gmclam
Fri Jan 04, 2008 2:18 pm
Forum: General Discussion
Topic: Some thoughts on terrestrial digital broadcasting...
Replies: 27
Views: 6991

ATSC is the best kept secret in America

Let's see .. so many comments to make here. Regarding music media; I've always felt that as long as a motor was involved the technology is archaic. Most of my music is on vinyl (that was the best media when I started collecting) and I didn't own a music CD until 1/1/2000. Now that everything is movi...
by gmclam
Fri Jan 04, 2008 1:57 pm
Forum: Up For Grabs
Topic: WANTED: 7.50000 MHz osc
Replies: 5
Views: 3522

Thank you

Thanks for all the ideas/posts. I ended up using a 15.0 MHz osc and a 74LS74 to get the prototype working. I found a programmable osc at DigiKey and that solves my immediate needs. I did find the part at Fox, and requested some samples, but have not received them as of yet. For a production design I...
by gmclam
Sat Dec 15, 2007 6:06 pm
Forum: General Discussion
Topic: Modify NTSC Tuner to ATSC Digital Tuner?
Replies: 6
Views: 2086

Yeah I knew we were talking about portable TVs. And the OP wanted to just put in a digital tuner. LOL. I highly suspect the converter boxes will be powered from "wall warts", which are typically DC. It shouldn't be a big problem for someone to provide battery power to the converter in addition to th...
by gmclam
Fri Dec 14, 2007 9:15 pm
Forum: Up For Grabs
Topic: WANTED: 7.50000 MHz osc
Replies: 5
Views: 3522

Thanks, I've considered that option. I already have a PCB and no room for an extra DIP package (for the divider), but will certainly squeeze any package oscillator on there I can find.
by gmclam
Fri Dec 14, 2007 7:15 pm
Forum: General Discussion
Topic: remote control system built with discrete components, chips
Replies: 9
Views: 2458

How about using InfraRed?

I'm not sure what "medium" you want to use - RF, InfraRed, UltraSound or something else. Remote controls for garage doors are usually RF, while home electronics use IR these days. IR stuff is plentiful and cheap. You could easily build the transmitter half from one of dozens of ICs available (or jus...
by gmclam
Fri Dec 14, 2007 7:06 pm
Forum: Up For Grabs
Topic: WANTED: 7.50000 MHz osc
Replies: 5
Views: 3522

WANTED: 7.50000 MHz osc

I'm not sure why this is such an odd frequency, but everywhere I've looked has come up empty. I've got 7.3728 and 7.8791 but I need 7.5000 . Ideally this should be a 5 volt part in a "14 pin dip" type case, but I'll consider whatever you might have at the correct frequency. Thank you & Happy Holidays
by gmclam
Fri Dec 14, 2007 7:03 pm
Forum: Up For Grabs
Topic: WANTED: Dead PRO-93 or PRO-95 for parts
Replies: 4
Views: 3330

LCD display

The one component I need most is the LCD display. It is 4 rows of 12 characters. Each character appears to be a 5x7 "dot matrix". I have a part number for the display, but have no clue who makes/made this part. Any searches I have done have come up empty. Perhaps someone out there has one, a link, o...
by gmclam
Fri Dec 14, 2007 6:53 pm
Forum: General Discussion
Topic: Modify NTSC Tuner to ATSC Digital Tuner?
Replies: 6
Views: 2086

ATSC reception

You are better off to wait a short time (1Q08) and purchase one of the new converter boxes. They are suppose to cost about $50 and will handle reception, down-rezzing pictures to 480i, and outputting the signal as RF and/or baseband. Take a look at all the stages needed to receive ATSC. It is not ju...
by gmclam
Fri Nov 30, 2007 8:38 pm
Forum: Up For Grabs
Topic: WANTED: Dead PRO-93 or PRO-95 for parts
Replies: 4
Views: 3330

They are scanning radios.
by gmclam
Tue Nov 27, 2007 10:03 pm
Forum: Computer Programming
Topic: Philips PXAG49...
Replies: 4
Views: 4109

PXAG49 in circuit FLASH programming

I've actually written code, which under software control can vector to the factory boot loader routine. I added this code after several CPUs failed and could not be programmed in circuit. Included in my routines are the ability to read all the registers (including AUXR) and the values loaded at BPC....
by gmclam
Tue Nov 27, 2007 3:44 pm
Forum: Computer Programming
Topic: Philips PXAG49...
Replies: 4
Views: 4109

Yes the ENBOOT flag in the AUXR register can be overwritten. However, that condition is overwritten because of the hardware state of 2 pins at power on, as per note 8 on page 8: 8. The AUXR reset value is typically 00h. If the Boot Loader is activated at reset because the Flash status byte is non-ze...