Re: SA612AN - really hot when VCC is applied


Chris Smith <me@...>
 

Agree on all counts. Worth looking on Aliexpress though as most of the
cheap adapter boards are sourced from that direction anyway.
Possibly a diversion away from the point, but at this point in time I'm
loathed to invest any time in anything that isn't SMD and a modern
design now. Getting slightly tired of chasing down highly in demand
parts which are drying up rapidly and being taken advantage of by
scammers. Nearly all the classic parts and a hell of a lot of really
good new ones are still available from respectable distributors in SMD
form on that side of the fence too.
I reckon you could put together a fully SMD norcal 40A with a Si5351A
replacing the VFO and BFO oscillators and integrating a keyer for less
size and cost than a TH one for example, although that might be treading
on the toes of the K1 a little bit :)
Best regards,

Chris Smith M0XTE

On Mon, 24 Sep 2018, at 09:43, Shirley Dulcey KE1L wrote:
I don't think anybody has said that the surface mount SA602 and SA612> parts are scarce. They're still in production and readily available
from distributors.

What is getting scarce is the through-hole version. NXP (successor to> Signetics and Philips) stopped making them a while ago and supplies
are drying up. Diz still has them for now, as does the Switch and
Parts Store (WB9KZY). The Elecraft KX1 switched to using an SMD mixer> and an adapter board before it went out of production, and I suspect
the K2 has done that as well. Generic 8-SOIC to 8-PDIP adapter boards> are available from many sources. One example is the SparkFun
BOB-13655, which is $2.95 for a board that's actually four break-apart> adapters. Another example is the Adafruit 1212: $2.95 for a six pack
of boards. You also need headers; the inexpensive snap-apart ones will> work just fine. I have also seen adapters from Schmartboard and
generic ones for sale at hamfests.

The chip on many of the 8-SOIC adapters is rotated 90 degrees from the> position of the adapter. Make sure to point everything the right way.>
One downside of using adapters is that the bypass capacitors are
farther away from the chip. If that turns out to be a problem you can> try putting an SMD bypass cap on the adapter board.

If you get desperate, the NTE7164 is an SA602-compatible part. But you> won't enjoy the price tag.

Although MSOP adapters also exist, don't try to use one with an
Si5351A. That chip is fussy about the lead lengths of its bypass
capacitor and crystal. A much better idea is to use an Si5351A
breakout board; they are available from Adafruit, QRP Labs, and
Etherkit.

It appears that some opportunists are selling counterfeit parts. Be
wary of SA602 and SA612 DIPs (or the older NE602 and NE612 if anybody> offers those) from eBay and Ali Express.
On Mon, Sep 24, 2018 at 1:03 AM Michael <pixelwaster@gmail.com> wrote:>>
Arrow.com has smd SA612 for $1.66 each. Minimum of 1 ordered
with free>> overnight shipping. They do ship overnight on a few parts! The next
break points are at 10/1.4988, 100/1.3005, 1000/1.008
The date code is 1708 from Thailand and they have 1900 in stock.
If you are willing to wait three day you can get the parts form the
Netherlands dated 1827. Still free shipping.

Michael
N9XYP

On 9/23/2018 10:17 PM, na5n_qrp wrote:

Kits and Parts (Diz) also has the thru-hole versions shown on his
website ... the NE602AN and NE612AN, as well as the SA602AD
SMT part.>>> 5 for $10, or $2 each. Mouser also has the SMD versions for $2.88/1>>> and $2.45/10 with 11,000 in stock. DigiKey has them as well
for $2.36>>> each with 1,000 in stock. Search for SA602 or SA612 ... NE602/612
produces no results and seldom shown in their catalogs, but
they have>>> them. They're not as rare as some have claimed.



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