Hans Summers wrote:


NE602 front-ends are even simpler than SBL-1 front ends. Contrary to
popular belief in some circles, you can still get the NE602 in 8-pin DIP,
new, from Philips: the new name, for an improved part, is SA612AN. (The N
suffix means 8-pin DIP.)


I don't think it's exactly like that.

The NE602 was manufactured by Signetics. Philips bought Signetics in 1975
from its previous parent company Corning Glass WOrks. In 1991 Philips
Semiconductors became a separate company within the Philips group, and
Signetics was integrated into Philips Semiconductors in 1993 to give greater
product recognition in the US. From what I understand Signetics was aquired
from Philips in 1995 by the Keo Pyung (KP) Group, and subsequently
transferred to private ownership.

Anyway, a few years ago legend has it that there was a fire at a Signetics
semiconductor manufacture plant in Korea, destroying (amongst other things)
the master die and several year's worth of NE602 stocks. This is what gave
rise to the rumour amongst radio amateurs already hit by dicontinuation of
other mixers, that the NE602 had been discontinued.

In fact it hadn't, Philips continued production of the NE602 as part SA602.
Philips also offered a less expensive but slightly inferior equivalent, the
SA612. Later, a new manufacturing process was developed producing better
performance and reliability, and at the same time minor changes were made to
the SA602/612 circuit to improve performance. The new devices are part
numbers SA602A and SA612A. The N suffix is for 8-pin DIP, D suffix for 8-Pin
SO Surface Mount.

So, both the SA602A and the SA612A are still in production by Philips, the
602 being slightly superior to the 612.

Incidentally, despite the datasheet sating the internal oscillator can be
used up to 200MHz, I am having a lot of success using it in a VCO covering
range 140-300MHz. See some preliminary pictures of my spectrum analyser
project http://www.hanssummers.com/electroni...ctrumanalyser/.

Hans,

Looks interesting. Back in the early '90s I built a similar project,
described in Electronics Australia magazine some time in 1992. It used a
TV tuner as the front end and an NE602 as the converter, and displays
the signal on any old CRO.

Strangely, I only just got it out of hiding a few days ago and fixed a
fault with one of the rotary switches. It hasn't been used in many years
but I recently gave away my AM/FM tuner, and I remembered that this
Spectrum Analyzer has the neat ability to tune in and play FM radio,
which is why I bothered to get it going again.

It covers the ranges 88-108MHz, 138-225MHz and 470-870MHz which as you
can see is discontinuous. This is because of the tuner, but nowadays you
can get tuners that don't have gaps in their coverage.

Electronics Australia no longer exists, sadly; it closed in 2001 after
an illustrious 80 years or so, having begun as "Radio & Hobbies" in the
'20s. However, reprints of almost all articles are available from
http://www.siliconchip.com.au for about AU$10.00

Rob

"W7TI" wrote in message
...
On 22 Jul 2003 00:10:59 GMT, (ScottnDess) wrote:

I already said i was sorry. What else do you want me to do?


__________________________________________________ _______

You just don't get it do you?

Nobody wants your apology. I/we want you to learn proper English. The
rules of English exist for a reason - to facilitate communication.

I'm probably wasting my time with this, but it annoys me no end to see
someone who has some potential throw it away with such rotten grammar.

Enough said, I'm through. Do it or not, your choice.

--
Bill, W7TI


Did I miss something here? I thought this was the
'rec.radio.amateur.homebrew' newsgroup, and not the
'rec.strictly.correct.grammar&spelling' group.

Are we really so damn petty that we must carry on like spoilt little brats
just because his spelling or grammar is not perfect? Is that what our hobby
is all about? No wonder amateur radio is dying out.

Get a damn life! Yes, OK, his spelling and grammar was annoying, but so is
more than half of the people who post to newsgroups. I don't recall
absolutely correct spelling & grammar being a mandatory requirement for
entry to internet newsgroups, or amateur radio for that matter. And what
the hell has his resume got to do with a posting in a newsgroup? I wasn't
aware that he WAS applying for a job here!

Grow up, please, and get a life outside your office of divine intervention!

73's and very best wishes

Martin, VK2UMJ

PS - I sincerely hope my spelling and grammar met the high standards of this
newsgroup............

or, should that be: i sinserley hope me speling and gramar are good enuf
for ya news group, mate....

"W7TI" wrote in message
...
On 22 Jul 2003 00:10:59 GMT, (ScottnDess) wrote:

I already said i was sorry. What else do you want me to do?


__________________________________________________ _______

You just don't get it do you?

Nobody wants your apology. I/we want you to learn proper English. The
rules of English exist for a reason - to facilitate communication.

I'm probably wasting my time with this, but it annoys me no end to see
someone who has some potential throw it away with such rotten grammar.

Enough said, I'm through. Do it or not, your choice.

--
Bill, W7TI


Did I miss something here? I thought this was the
'rec.radio.amateur.homebrew' newsgroup, and not the
'rec.strictly.correct.grammar&spelling' group.

Are we really so damn petty that we must carry on like spoilt little brats
just because his spelling or grammar is not perfect? Is that what our hobby
is all about? No wonder amateur radio is dying out.

Get a damn life! Yes, OK, his spelling and grammar was annoying, but so is
more than half of the people who post to newsgroups. I don't recall
absolutely correct spelling & grammar being a mandatory requirement for
entry to internet newsgroups, or amateur radio for that matter. And what
the hell has his resume got to do with a posting in a newsgroup? I wasn't
aware that he WAS applying for a job here!

Grow up, please, and get a life outside your office of divine intervention!

73's and very best wishes

Martin, VK2UMJ

PS - I sincerely hope my spelling and grammar met the high standards of this
newsgroup............

or, should that be: i sinserley hope me speling and gramar are good enuf
for ya news group, mate....

The
Kit Radio Company
Invites you to visit our web site
http://hometown.aol.co.uk/kitradioco/uk.htm



Thank you!!

Scott

The
Kit Radio Company
Invites you to visit our web site
http://hometown.aol.co.uk/kitradioco/uk.htm



Thank you!!

Scott

John S. MacKay wrote:
What college teaches the spelling of the word "amature"? On second
thought, don't bother.

Not college, it's that hobbiest place. You know, the one that's hobbier
than all the others.

--
All relevant people are pertinent.
All rude people are impertinent.
Therefore, no rude people are relevant.
-- Solomon W. Golomb

John S. MacKay wrote:
What college teaches the spelling of the word "amature"? On second
thought, don't bother.

Not college, it's that hobbiest place. You know, the one that's hobbier
than all the others.

--
All relevant people are pertinent.
All rude people are impertinent.
Therefore, no rude people are relevant.
-- Solomon W. Golomb

I find it remarkable that, in a hobby that requires a multitude of non-
English expressions and anachronisms, we have an old timer who's faulting
someone's use of the Queens English! Presumably, W7TI also refuses QSO's
with anyone who is unable to speak fluent, clear English. Even in my
humble experience, I can see that such an approach to our hobby is
inappropriate and one must surely feel sorry for W7TI and the small world
he has limited himself to. Bill; you have my sympathy and thoughts.

Scott, on behalf of all amature radio operators who uphold the tradition of
making contact with a fellow enthusiast despite the QRM around them, I wish
you all the best. I, to, am in the process of selecting a suitable HF
design and I'll follow this thread with interest.
For what it's worth, here's my observations of starting out at homebrewing
- and I'll bet this starts a run of mail as well!:

1. Select a kit if your confidence or experience is minimal. Some kit
manufacturers even offer a 'get-you-running' service to iron out those
little bugs that creep in.

2. Ensure you can beg / borrow suitable test kit. You'll probably need a
multimeter or two, a resonable power supply (ideally, a current-limiting
one), an RF probe (do a Google search; they're easy & cheap to make), dummy
loaad (again, Google) and an oscilloscope. There's nothing worse than
having a circuit board on the desk & no means of knowing if it's okay to
proceed with the next bit!
Other items might well include: RF Watt meter, Frequency counter, RF
Generator.... the list can go on! Make friends with locals.

3. Accept that this project will take about three times more time than you
planned for. On reflection, that might just be me: I'm not that skilled!


Re. the earlier post about 'by small you mean simple'. I couldn't agree
more! Personally, I'd avoid building the all-singing, all dancing radio
some of the books advocate unless you or one of the locals you're now very
friendly with has experience of debugging such a beast. For me, half the
fun is building, so I'm already poking about for a suitable something for
when the current VHF SSB set is finished!

Good luck & I hope you find a suitable diagram / kit / idea to work on. I
look forward to hearing you on the air with it - there's nothing better
than that first QSO with a homebrew!

Regards,
Dave


Anyone who wants to comment on the essential tools for beginners, would you
mind starting a new post please? It will help keep this one on-topic.
Thanks & see you all on-air.

=============================================

__________________________________________________ _______

"not perfect"? Understatement of the day.

Like they say, Martin, you're either part of the solution or part of
the problem. Apologists like you who accept and tolerate lousy
grammar and spelling help perpetuate the problem. Like I said, the
rules of English exist for a reason. Learn them and do it right.

I don't care about the occasional typo - I make 'em too - but when a
message is so laden with errors it becomes hard to merely read it....

I find it remarkable that, in a hobby that requires a multitude of non-
English expressions and anachronisms, we have an old timer who's faulting
someone's use of the Queens English! Presumably, W7TI also refuses QSO's
with anyone who is unable to speak fluent, clear English. Even in my
humble experience, I can see that such an approach to our hobby is
inappropriate and one must surely feel sorry for W7TI and the small world
he has limited himself to. Bill; you have my sympathy and thoughts.

Scott, on behalf of all amature radio operators who uphold the tradition of
making contact with a fellow enthusiast despite the QRM around them, I wish
you all the best. I, to, am in the process of selecting a suitable HF
design and I'll follow this thread with interest.
For what it's worth, here's my observations of starting out at homebrewing
- and I'll bet this starts a run of mail as well!:

1. Select a kit if your confidence or experience is minimal. Some kit
manufacturers even offer a 'get-you-running' service to iron out those
little bugs that creep in.

2. Ensure you can beg / borrow suitable test kit. You'll probably need a
multimeter or two, a resonable power supply (ideally, a current-limiting
one), an RF probe (do a Google search; they're easy & cheap to make), dummy
loaad (again, Google) and an oscilloscope. There's nothing worse than
having a circuit board on the desk & no means of knowing if it's okay to
proceed with the next bit!
Other items might well include: RF Watt meter, Frequency counter, RF
Generator.... the list can go on! Make friends with locals.

3. Accept that this project will take about three times more time than you
planned for. On reflection, that might just be me: I'm not that skilled!


Re. the earlier post about 'by small you mean simple'. I couldn't agree
more! Personally, I'd avoid building the all-singing, all dancing radio
some of the books advocate unless you or one of the locals you're now very
friendly with has experience of debugging such a beast. For me, half the
fun is building, so I'm already poking about for a suitable something for
when the current VHF SSB set is finished!

Good luck & I hope you find a suitable diagram / kit / idea to work on. I
look forward to hearing you on the air with it - there's nothing better
than that first QSO with a homebrew!

Regards,
Dave


Anyone who wants to comment on the essential tools for beginners, would you
mind starting a new post please? It will help keep this one on-topic.
Thanks & see you all on-air.

=============================================

__________________________________________________ _______

"not perfect"? Understatement of the day.

Like they say, Martin, you're either part of the solution or part of
the problem. Apologists like you who accept and tolerate lousy
grammar and spelling help perpetuate the problem. Like I said, the
rules of English exist for a reason. Learn them and do it right.

I don't care about the occasional typo - I make 'em too - but when a
message is so laden with errors it becomes hard to merely read it....