|
SN 602, SA602 etc. for an R4C
I'm really interested in building the product detector and second and third
mixers for my R4C as described in the recent QEX article. My question is (and please pardon my ignorance) in 2 places an SN 602 IC is called for but I can find no trace of such a component anywhere. Is the SA 602 or NE 602 the same? I'm a ham but a musician by trade and learning this stuff as I go. Thanks in advance. Andy W1AWB |
SN 602, SA602 etc. for an R4C
Thanks Allison!
|
SN 602, SA602 etc. for an R4C
The NE602 was an old part. The product was bought by another company
(Signetics?) who renamed it SA602, but kept the rights to the name NE602 so sometimes you still find an NE602. Worse yet, the NE/SA 612 is a little more widely available and somewhat cheaper -- sometimes a lot cheaper. It is the same part with a little different set of QC tests, so for any imaginable application, all 4 parts are the same thing. If you were doing some military application there might be a slight advantage to the 602 over the 612, but even that isn't clear from the spec sheets. Usually (but not always) if you find an NE part it will be "old stock". Sometimes the 602 will be a few cents more than a 612, other times it will be 2 or 3 times the price, although it's only a couple buck part so paying double isn't going to break the bank, anyway. The NE602 was widely used in a lot of projects, and still is. Hams got used to calling it an NE602 so the name stuck, even though an actual NE602 is hard to find anymore and the alternatives at least as good. Guys who build lots of receivers have a drawer marked NE602 that probably contains more SA612's than NE602's. ... "Andy Bullington" wrote in message . .. I'm really interested in building the product detector and second and third mixers for my R4C as described in the recent QEX article. My question is (and please pardon my ignorance) in 2 places an SN 602 IC is called for but I can find no trace of such a component anywhere. Is the SA 602 or NE 602 the same? I'm a ham but a musician by trade and learning this stuff as I go. Thanks in advance. Andy W1AWB |
SN 602, SA602 etc. for an R4C
xpyttl wrote:
The NE602 was an old part. Speaking of the NE602 - the old one - I have a question... Is my chip dead, or is 40 meters dead? I recently got re-interested in RF and pulled out some old parts to play with. I wired up an NE602 on a breadboard (yeah, I know), with a torroid, some padding caps, and a varactor for tuning, and got is oscillating on what my scope (yeah, I know) claimed was around 7 mhz. Lots of domestic AM broadcast interference eventually tamed, but then only shortware broadcast received at these frequencies (ie, tunes like AM should with a direct conversion receiver) - no ham CW. I do remember from way back when that I found the novice 40m band useless in the evenings and would hang out on 15m then instead. Is that still true right now? I know the receiver isn't totally dead as I increased the capacitance, tuned it down to what my scope claims is 80 meteres, and heard CW. Added an old op-amp audio filter circuit from the handbook and it's almost useable on 80m, but tuned back up to forty and nothing but broadcast... What kind of ballpark magintude of oscillation should I measure if I probe the tank (well, actually pin 7) with a high impedance probe? |
SN 602, SA602 etc. for an R4C
In article . com,
wrote: Speaking of the NE602 - the old one - I have a question... Is my chip dead, or is 40 meters dead? Can't say anything about the health of your chip. There are times when 40 meters is dead, or pretty weak. There are other days when it's fine. Sunspot numbers have been quite low lately. The Western States Noontime Net on 40 meters was fairly weak today and was weak yesterday... the net controls commented that propagation was horrible. For a couple of days before that, propagation was excellent and signals were just booming in. Lots of domestic AM broadcast interference eventually tamed, but then only shortware broadcast received at these frequencies (ie, tunes like AM should with a direct conversion receiver) - no ham CW. I do remember from way back when that I found the novice 40m band useless in the evenings and would hang out on 15m then instead. Is that still true right now? I don't ever hear much in the old 40-Novice band segment. There's enough foreign-broadcast interference after dark these days to drive most ham activity out of the 7100-7300 frequencies. There's usually some CW pipping away down at the very low end of 40 almost any time I tune around to check. The phone segment on 40 is usually quite active during the day, if the band conditions aren't too horrible, since most of the foreign broadcast interference is heavily attenuated. My impression is that 15 is as dead as a doornail after sunset these days. -- Dave Platt AE6EO Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads! |
| All times are GMT +1. The time now is 09:15 PM. |
Powered by vBulletin® Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
RadioBanter.com