RadioBanter - Frequency Division

RadioBanter (https://www.radiobanter.com/)

- Homebrew (https://www.radiobanter.com/homebrew/)

- - Frequency Division (https://www.radiobanter.com/homebrew/22374-frequency-division.html)

I'm new to the newsgroup and am sure that this is not the first gripe
about
SMD's, but I refuse to use them - not because I can't (at least not yet),
but because I don't want to endure the angst.
===================================
The above proves that a basic bottleneck in humans is the tendency to
resist change.
Fortunately there are also many (humans) who see change as a challenge.
I prefer to belong to the latter category and will shortly 'get into SMD' by
building a DDS VFO
(ref KG6CYN) ,be it that I am currently doing some 'home training' by
messing about with SMD components from discarded consumer electronics.
After all homebrewing electronics is and remains a great hobby.

Frank GM0CSZ / KN6WH

"ChipS" wrote in message
...
Thanks to all for the replys. Thanks particularly to Joe and Mike W. for
the good info.on the daughterboard and soldering service.

Read the latest QEX. The frequency synthesizer article contains hints on
soldering 0.6 mm spaced surface mount leads.

On Wed, 25 Feb 2004 07:51:15 +0000, "Ian White, G3SEK"
wrote:

[snip]

|Oh yes, and lay off the coffee and Coke for several hours beforehand!

No kidding!

During the development of the Phoenix Missile Solid State Transmitter,
which used 16 IMPATT diodes in a cavity power combiner, we were
serializing every diode.

The state of the art in diode manufacturing was such that getting 16
matched devices was almost impossible, so we tested hundreds and then
picked those that most closely matched. These were a microwave pill
package with a 3-48 screw and a flange about 2mm in diameter. We
scribed about a 10 digit serial number right into the gold on the
flange.

I was good for about 30 diodes each morning until the coffee and
shakes set it.

SWbeginner wrote in message
...
How high can the 74HC4066 as mixer go?
I need 50Mhz tops.

I still like to know how strong dual gate MOSFET is compared to say diode
ring.

thx

?

The HC4066 is OK(ish) to about 10megs.
A dual gate fet (eg 40673) -with care- should be able give out roughly the
same, or a little more voltage than what is coming in. With a diode ring
expect to pick up (say) only 40mV of an incoming 100mV.
[Easiest / most reliable]: use a "Bus Switch" such as the FST3125, toggled
by 74AC type logic; handle the A.C. signals by couple of video op-amps).
('Output' signal looks like what you see in a text book).
regards
john

"ChipS" wrote in message
...

Joe, I'd gladly use the Analog Devices DDS chips if they offered them in
something other than a SadoMasochistic Device (SMD) package. It's a darn
shame they can't make a limited run (say 10k) of some of these chips in a
PDIP package for hams and other r.f. experimenters.

That would be cost-prohibitive ... to tool up to make the parts in obsolete
packages
that the production line is no longer using would cost a fortune.

If they put the AD9835 in a PDIP and sold it for about $10.00 (the TSSOP
packaged version sells for about $6, I think) , I'd buy a dozen for
various
projects, but in the tiny SMD package they're nothing but useless to me.

I'm new to the newsgroup and am sure that this is not the first gripe
about
SMD's, but I refuse to use them - not because I can't (at least not yet),
but because I don't want to endure the angst.

What "angst"??? SMD parts are not "hard to work with" - they just require
that you learn and use different techniques ... the ARRL has some very good
material on their website on using SMD parts.

73,
Carl - wk3c

Carl R. Stevenson wrote:

Joe, I'd gladly use the Analog Devices DDS chips if they offered them in
something other than a SadoMasochistic Device (SMD) package. It's a darn
shame they can't make a limited run (say 10k) of some of these chips in a
PDIP package for hams and other r.f. experimenters.

That would be cost-prohibitive ... to tool up to make the parts in
obsolete packages that the production line is no longer using would
cost a fortune.

Absolutely right, Carl - it ain't gonna happen.

A very good article in 'Communications Quarterly' (RIP) explained how
the IC samples system works. Basically the economics of complex ICs are
the same as for developing a new drug - most of the selling price is
aimed at recovering the large upfront development costs. By comparison,
once the line is set up and rolling, the *production* cost of the actual
parts (or pills) is often quite minimal. It's a very good investment to
give away samples as bait, if they're going to help reel in orders for
large quantities.

Analog Devices (and also Maxim) are very clear that samples supplied to
amateurs are much less likely to bring in orders than those supplied to
commercial developers... yet they do it anyway, for the public good, and
because it doesn't cost them much. And we're very grateful for it.

But that's as far as their charity extends. As Carl says, nobody is ever
going to provide free samples of anything for which there's no
commercial market.

Frankly, it's also as far as charity to amateurs and other experimenters
*should* extend. They are not in business to featherbed us.

Fortunately, most amateurs have a "can do" attitude towards SMD. This
just arrived on another mailing list:

I broke my neck a few years ago and due to nerve damage my hands don't
work as well as they did but I was able to do the mod
[which involved SMD work on a $2000 transceiver]
without much trouble. I did it before the rig had even been on the
air, brand new out of the box, scary, yes but worth it.

I'm proud to be in the same ham community as that person.

--
73 from Ian G3SEK 'In Practice' columnist for RadCom (RSGB)

http://www.ifwtech.co.uk/g3sek