SA612AN - really hot when VCC is applied


Richard Seguin
 

Hello folks,

I'm experiencing a very fishy situation with a batch of NE612AN double
balanced mixers that I got from China. When I apply power to the correct
pin (I verified several times) they get really hot to the touch. I created
a test circuit that is similar to what the datasheet specifies for an
unbalanced input, and I have also played around with using a crystal
oscillator instead of the DDS output that I wanted to use.

I'm not looking for anyone to troubleshoot my circuit, I'm more or less
curious if anyone else ran into symptoms like this. I'm suspecting that
what I have may not be SA612AN mixers, and that I am applying power to the
incorrect pins.

If anyone has one of these laying around, what happens when you apply VCC
(5V) to pin 8 and GND to pin 3? Does the IC heat up?

Richard (VE9IT)


Chris Smith <me@...>
 

Sounds like they are hooky. This is happening very frequently with
popular parts. Get one out and measure the following with a DMM on ohms.
From the datasheet there should be the following approximate resistances
between the pins:
7 -> 3 = 25k
1 -> 3 = 1.5k
2 -> 3 = 1.5k
6 -> 4 = 19.5k
6 -> 5 = 19.5k

If all of these are vastly off then it's probably not a 612.

Finding out what it really is could be interesting :)

Best regards,

Chris Smith M0XTE

On Sun, 23 Sep 2018, at 20:51, Richard Seguin wrote:
Hello folks,

I'm experiencing a very fishy situation with a batch of NE612AN double> balanced mixers that I got from China. When I apply power to
the correct> pin (I verified several times) they get really hot to the touch.
I created> a test circuit that is similar to what the datasheet specifies for an> unbalanced input, and I have also played around with using a crystal
oscillator instead of the DDS output that I wanted to use.

I'm not looking for anyone to troubleshoot my circuit, I'm
more or less> curious if anyone else ran into symptoms like this. I'm
suspecting that> what I have may not be SA612AN mixers, and that I am applying
power to the> incorrect pins.

If anyone has one of these laying around, what happens when you
apply VCC> (5V) to pin 8 and GND to pin 3? Does the IC heat up?

Richard (VE9IT)



Richard Seguin
 

Haha not even close! I'm actually getting no impedance values back on any
of the pins mentioned. I even used an IC that was still in the tube.

Well, this was an afternoon wasted. I learned a valuable lesson though
about China components.

Thanks again,

Richard (VE9IT)

On Sun, Sep 23, 2018, 4:56 PM Chris Smith <me@m0xte.uk> wrote:

Sounds like they are hooky. This is happening very frequently with
popular parts. Get one out and measure the following with a DMM on ohms.
From the datasheet there should be the following approximate resistances
between the pins:
7 -> 3 = 25k
1 -> 3 = 1.5k
2 -> 3 = 1.5k
6 -> 4 = 19.5k
6 -> 5 = 19.5k

If all of these are vastly off then it's probably not a 612.

Finding out what it really is could be interesting :)

Best regards,

Chris Smith M0XTE


On Sun, 23 Sep 2018, at 20:51, Richard Seguin wrote:
Hello folks,

I'm experiencing a very fishy situation with a batch of NE612AN double>
balanced mixers that I got from China. When I apply power to
the correct> pin (I verified several times) they get really hot to the
touch.
I created> a test circuit that is similar to what the datasheet
specifies for an> unbalanced input, and I have also played around with
using a crystal
oscillator instead of the DDS output that I wanted to use.

I'm not looking for anyone to troubleshoot my circuit, I'm
more or less> curious if anyone else ran into symptoms like this. I'm
suspecting that> what I have may not be SA612AN mixers, and that I am
applying
power to the> incorrect pins.

If anyone has one of these laying around, what happens when you
apply VCC> (5V) to pin 8 and GND to pin 3? Does the IC heat up?

Richard (VE9IT)






Chris Smith <me@...>
 

Doh! 602's / 612's are getting rather expensive now. Looks like someone
disreputable has decided to make some easy money.
Have been wondering if there is a better IC on the market now for less
money. I was looking the other day for MMICs to build a noise source for
my SA. First visit to the traditional Mini-Circuits and decided to hell
with paying for those parts. So I looked around and found some really
cheap ones with good enough specification for virtually nothing. There
must be a part out there with similar utility for less money these days.
Best regards,

Chris Smith M0XTE

On Sun, 23 Sep 2018, at 21:12, Richard Seguin wrote:
Haha not even close! I'm actually getting no impedance values
back on any> of the pins mentioned. I even used an IC that was still in the tube.

Well, this was an afternoon wasted. I learned a valuable lesson though> about China components.

Thanks again,

Richard (VE9IT)

On Sun, Sep 23, 2018, 4:56 PM Chris Smith <me@m0xte.uk> wrote:

Sounds like they are hooky. This is happening very frequently with
popular parts. Get one out and measure the following with a DMM
on ohms.>> From the datasheet there should be the following approximate
resistances>> between the pins:
7 -> 3 = 25k
1 -> 3 = 1.5k
2 -> 3 = 1.5k
6 -> 4 = 19.5k
6 -> 5 = 19.5k

If all of these are vastly off then it's probably not a 612.

Finding out what it really is could be interesting :)

Best regards,

Chris Smith M0XTE


On Sun, 23 Sep 2018, at 20:51, Richard Seguin wrote:
Hello folks,

I'm experiencing a very fishy situation with a batch of NE612AN
double>>> balanced mixers that I got from China. When I apply power to
the correct> pin (I verified several times) they get really hot
to the>> touch.
I created> a test circuit that is similar to what the datasheet
specifies for an> unbalanced input, and I have also played
around with>> using a crystal
oscillator instead of the DDS output that I wanted to use.

I'm not looking for anyone to troubleshoot my circuit, I'm
more or less> curious if anyone else ran into symptoms like
this. I'm>>> suspecting that> what I have may not be SA612AN mixers, and
that I am>> applying
power to the> incorrect pins.

If anyone has one of these laying around, what happens when you
apply VCC> (5V) to pin 8 and GND to pin 3? Does the IC heat up?

Richard (VE9IT)







Richard Seguin
 

I think that this might be a great time to learn how the double balanced
diode ring mixers work. At least we know what's in those.

On Sun, Sep 23, 2018 at 5:52 PM Chris Smith <me@m0xte.uk> wrote:

Doh! 602's / 612's are getting rather expensive now. Looks like someone
disreputable has decided to make some easy money.
Have been wondering if there is a better IC on the market now for less
money. I was looking the other day for MMICs to build a noise source for
my SA. First visit to the traditional Mini-Circuits and decided to hell
with paying for those parts. So I looked around and found some really
cheap ones with good enough specification for virtually nothing. There
must be a part out there with similar utility for less money these days.
Best regards,

Chris Smith M0XTE


On Sun, 23 Sep 2018, at 21:12, Richard Seguin wrote:
Haha not even close! I'm actually getting no impedance values
back on any> of the pins mentioned. I even used an IC that was still in
the tube.

Well, this was an afternoon wasted. I learned a valuable lesson though>
about China components.

Thanks again,

Richard (VE9IT)

On Sun, Sep 23, 2018, 4:56 PM Chris Smith <me@m0xte.uk> wrote:

Sounds like they are hooky. This is happening very frequently with
popular parts. Get one out and measure the following with a DMM
on ohms.>> From the datasheet there should be the following approximate
resistances>> between the pins:
7 -> 3 = 25k
1 -> 3 = 1.5k
2 -> 3 = 1.5k
6 -> 4 = 19.5k
6 -> 5 = 19.5k

If all of these are vastly off then it's probably not a 612.

Finding out what it really is could be interesting :)

Best regards,

Chris Smith M0XTE


On Sun, 23 Sep 2018, at 20:51, Richard Seguin wrote:
Hello folks,

I'm experiencing a very fishy situation with a batch of NE612AN
double>>> balanced mixers that I got from China. When I apply power to
the correct> pin (I verified several times) they get really hot
to the>> touch.
I created> a test circuit that is similar to what the datasheet
specifies for an> unbalanced input, and I have also played
around with>> using a crystal
oscillator instead of the DDS output that I wanted to use.

I'm not looking for anyone to troubleshoot my circuit, I'm
more or less> curious if anyone else ran into symptoms like
this. I'm>>> suspecting that> what I have may not be SA612AN mixers,
and
that I am>> applying
power to the> incorrect pins.

If anyone has one of these laying around, what happens when you
apply VCC> (5V) to pin 8 and GND to pin 3? Does the IC heat up?

Richard (VE9IT)









--
Richard


Chris Smith <me@...>
 

That's a good point. I built a couple of them a few years back when I
was playing with Farhan VU2ESE's DC40. Somewhat tedious to sling
together but they do work very well. In fact the first "active" part of
my commercial SA is a simple diode DBM which I am forever afraid of
blowing up :)
However not quite as integrated as the 602/612's as they have a pretty
decent LO built in as well. Imagine how much more complicated the NC40A
would be without three of them in it.
Best regards,

Chris Smith M0XTE

On Sun, 23 Sep 2018, at 22:34, Richard Seguin wrote:
I think that this might be a great time to learn how the double
balanced> diode ring mixers work. At least we know what's in those.

On Sun, Sep 23, 2018 at 5:52 PM Chris Smith <me@m0xte.uk> wrote:

Doh! 602's / 612's are getting rather expensive now. Looks like
someone>> disreputable has decided to make some easy money.
Have been wondering if there is a better IC on the market now
for less>> money. I was looking the other day for MMICs to build a noise
source for>> my SA. First visit to the traditional Mini-Circuits and decided
to hell>> with paying for those parts. So I looked around and found some really>> cheap ones with good enough specification for virtually
nothing. There>> must be a part out there with similar utility for less money
these days.>> Best regards,

Chris Smith M0XTE


On Sun, 23 Sep 2018, at 21:12, Richard Seguin wrote:
Haha not even close! I'm actually getting no impedance values
back on any> of the pins mentioned. I even used an IC that was
still in>> the tube.

Well, this was an afternoon wasted. I learned a valuable lesson
though>>> about China components.

Thanks again,

Richard (VE9IT)

On Sun, Sep 23, 2018, 4:56 PM Chris Smith <me@m0xte.uk> wrote:

Sounds like they are hooky. This is happening very frequently with>>>> popular parts. Get one out and measure the following with a DMM
on ohms.>> From the datasheet there should be the following
approximate>>>> resistances>> between the pins:
7 -> 3 = 25k
1 -> 3 = 1.5k
2 -> 3 = 1.5k
6 -> 4 = 19.5k
6 -> 5 = 19.5k

If all of these are vastly off then it's probably not a 612.

Finding out what it really is could be interesting :)

Best regards,

Chris Smith M0XTE


On Sun, 23 Sep 2018, at 20:51, Richard Seguin wrote:
Hello folks,

I'm experiencing a very fishy situation with a batch of NE612AN
double>>> balanced mixers that I got from China. When I apply
double>>> power to>>>>> the correct> pin (I verified several times) they get really hot
to the>> touch.
I created> a test circuit that is similar to what the datasheet
specifies for an> unbalanced input, and I have also played
around with>> using a crystal
oscillator instead of the DDS output that I wanted to use.

I'm not looking for anyone to troubleshoot my circuit, I'm
more or less> curious if anyone else ran into symptoms like
this. I'm>>> suspecting that> what I have may not be SA612AN
mixers,>> and
that I am>> applying
power to the> incorrect pins.

If anyone has one of these laying around, what happens when you
apply VCC> (5V) to pin 8 and GND to pin 3? Does the IC heat up?

Richard (VE9IT)









--
Richard



Terry VK5TM
 

If you don't mind using the smd version, '602's are still rather plentiful and not that expensive ($2 each here in Oz).
Mount them on an 8 pin smd/dip adapter (I bought 100 for a couple of dollars last year), just like using the through hole version.

The through hole ones stopped being made as far as I am aware some time ago, which is why they are now getting expensive.

--
Terry VK5tm
www.vk5tm.com ( http://www.vk5tm.com )


Richard Seguin
 

I noticed this evening that www.kitsandparts.com sells some of those SMD
mixers. They are not difficult to solder, so I'll likely throw a few into
my next toroid order.

I wonder which performs better, the active mixers like the SA612 or a
something passive diode ring. I think that I'll build both.

Richard (VE9IT)

On Sun, Sep 23, 2018, 9:02 PM Terry VK5TM <vk5tm@internode.on.net> wrote:

If you don't mind using the smd version, '602's are still rather plentiful
and not that expensive ($2 each here in Oz).
Mount them on an 8 pin smd/dip adapter (I bought 100 for a couple of
dollars last year), just like using the through hole version.

The through hole ones stopped being made as far as I am aware some time
ago, which is why they are now getting expensive.

--
Terry VK5tm
www.vk5tm.com ( http://www.vk5tm.com )




Curt
 

Richard

a ring mixer using ordinary silicon diodes and a pair of FT37-43 baluns achieves a lot more linearity as a first mixer. what we miss is the integration - need to provide our own amplifiers with it. check classic designs like 2n2-40 to get a feel for these circuits.

the SA612 does make a respectable product detector - it is used there in the K2. I am using a W8DIZ universal receiver board as a product detector and audio amplifier. the kit is provided with SMT SA602 and LM386 ICs - everything else is through hole. these critters are not hard to solder under a magnifier.

if you want to experiment, you can leave the 3 stages of the Universal Rx unconnected on the board -- it has 2 SA612 stages and one audio amplifier. Chuck has videos on this project.

73 Curt

PS I overcame my fumbles - Universal Rx board successful with xtal filter, product detector and audio all working. I am also trying a breadboard of the VK3YE AGC circuit that uses a photoresistor and LED (not for this project).


for this project I will use a diode ring mixer and a high linearity IF amplifier up front.


Paul NA5N
 

Richard Seguin writes:

I noticed this evening that www.kitsandparts.com sells some of those SMD
mixers.
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.

I mount my surface mount NE602s or other SMD ICs on a homebrew Manhattan style adapter. Basically a small square of copper clad and cut the traces for the pins with a dremel tool and thin cutting wheel. Just 3 cuts for the 4 pins on each side, then cut those in two vertically to make the 8 pins. I trim them so the pins stick out 1/8 to 1/4 inch for soldering the connections and external components. Works great and cheap. A steady hand comes in handy!

Hard to complain over the $2-3 cost. You're buying a lot of proven functionality for a couple of bucks with the good ole 602 chip. Biggest problem is they have a low P1dB so can be easily overloaded when used as the front end RF mixer. However, I have never noticed that unless operating in close proximity to others, like Field Day. On the other hand, a few external components and you have a nice product detector with a BFO.

72, Paul NA5N


Michael
 

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.


Shirley Dulcey KE1L
 

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.



Mvs Sarma <mvssarma@...>
 

I think it is 2.45 each at 10 lot and NOT a lot total price.



On Mon, Sep 24, 2018 at 2:13 PM Shirley Dulcey KE1L <mark@buttery.org>
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.





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.




Mvs Sarma <mvssarma@...>
 

I used to by from one seller.
as I searched now I get the ebay item 362255962960

please search
this guy is genuine

On Mon, Sep 24, 2018 at 3:11 PM Mvs Sarma <mvssarma@gmail.com> wrote:

I think it is 2.45 each at 10 lot and NOT a lot total price.



On Mon, Sep 24, 2018 at 2:13 PM Shirley Dulcey KE1L <mark@buttery.org>
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.





Mvs Sarma <mvssarma@...>
 

People say that smd parts are more genuine on ebay etc than through hole
parts, and so we can be safe.

On Mon, Sep 24, 2018 at 4:16 PM Mvs Sarma <mvssarma@gmail.com> wrote:

I used to by from one seller.
as I searched now I get the ebay item 362255962960

please search
this guy is genuine


On Mon, Sep 24, 2018 at 3:11 PM Mvs Sarma <mvssarma@gmail.com> wrote:

I think it is 2.45 each at 10 lot and NOT a lot total price.



On Mon, Sep 24, 2018 at 2:13 PM Shirley Dulcey KE1L <mark@buttery.org>
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.







Chris Smith <me@...>
 

Hi,

Quick update on this. I was contacted off list with measurements on
another NE602AN. If you swap the probes round on pin pairs 1,3 and 2,3
this drops to around 4.7M so clearly this is activating a semiconductor
junction inside the device.
7 -> 3 = 25k 1 -> 3 = 9.86M ohms 2 -> 3 = 9.73M ohms 6 -> 4 = 19.5k 6
-> 5 = 19.5k
That should be enough to do a simple red/green test on a 612/602 to see
if it is actually one or not.
Many thanks to the additional contributor :)

Best regards,

Chris Smith M0XTE

On Sun, 23 Sep 2018, at 20:56, Chris Smith wrote:
Sounds like they are hooky. This is happening very frequently with
popular parts. Get one out and measure the following with a DMM
on ohms.> From the datasheet there should be the following approximate
resistances> between the pins:
7 -> 3 = 25k
1 -> 3 = 1.5k
2 -> 3 = 1.5k
6 -> 4 = 19.5k
6 -> 5 = 19.5k

If all of these are vastly off then it's probably not a 612.

Finding out what it really is could be interesting :)

Best regards,

Chris Smith M0XTE


On Sun, 23 Sep 2018, at 20:51, Richard Seguin wrote:
Hello folks,

I'm experiencing a very fishy situation with a batch of NE612AN
double> balanced mixers that I got from China. When I apply power to>> the correct> pin (I verified several times) they get really hot to
the touch.>> I created> a test circuit that is similar to what the datasheet
specifies for an> unbalanced input, and I have also played around
with using a crystal>> oscillator instead of the DDS output that I wanted to use.

I'm not looking for anyone to troubleshoot my circuit, I'm
more or less> curious if anyone else ran into symptoms like
this. I'm>> suspecting that> what I have may not be SA612AN mixers, and that I am
applying>> power to the> incorrect pins.

If anyone has one of these laying around, what happens when you
apply VCC> (5V) to pin 8 and GND to pin 3? Does the IC heat up?

Richard (VE9IT)





Richard Seguin
 

Hi Chris,

Thank you for passing this along. I am getting 50M ohm between 2 and 3 and
nothing on the reverse. The other pins yield similar results. I get values
that are way off the mark or none at all.

I'll keep them around until I can get a good batch and I'll see how they
compare, for now, I'm marking them as being counterfeit.

Richard (VE9IT)

On Mon, Sep 24, 2018 at 1:52 PM Chris Smith <me@m0xte.uk> wrote:

Hi,

Quick update on this. I was contacted off list with measurements on
another NE602AN. If you swap the probes round on pin pairs 1,3 and 2,3
this drops to around 4.7M so clearly this is activating a semiconductor
junction inside the device.
7 -> 3 = 25k 1 -> 3 = 9.86M ohms 2 -> 3 = 9.73M ohms 6 -> 4 = 19.5k 6
-> 5 = 19.5k
That should be enough to do a simple red/green test on a 612/602 to see
if it is actually one or not.
Many thanks to the additional contributor :)

Best regards,

Chris Smith M0XTE

On Sun, 23 Sep 2018, at 20:56, Chris Smith wrote:
Sounds like they are hooky. This is happening very frequently with
popular parts. Get one out and measure the following with a DMM
on ohms.> From the datasheet there should be the following approximate
resistances> between the pins:
7 -> 3 = 25k
1 -> 3 = 1.5k
2 -> 3 = 1.5k
6 -> 4 = 19.5k
6 -> 5 = 19.5k

If all of these are vastly off then it's probably not a 612.

Finding out what it really is could be interesting :)

Best regards,

Chris Smith M0XTE


On Sun, 23 Sep 2018, at 20:51, Richard Seguin wrote:
Hello folks,

I'm experiencing a very fishy situation with a batch of NE612AN
double> balanced mixers that I got from China. When I apply power to>>
the correct> pin (I verified several times) they get really hot to
the touch.>> I created> a test circuit that is similar to what the
datasheet
specifies for an> unbalanced input, and I have also played around
with using a crystal>> oscillator instead of the DDS output that I
wanted to use.

I'm not looking for anyone to troubleshoot my circuit, I'm
more or less> curious if anyone else ran into symptoms like
this. I'm>> suspecting that> what I have may not be SA612AN mixers,
and that I am
applying>> power to the> incorrect pins.

If anyone has one of these laying around, what happens when you
apply VCC> (5V) to pin 8 and GND to pin 3? Does the IC heat up?

Richard (VE9IT)







--
Richard


Bill Cromwell
 

When you say 'none at all' do you mean zero ohms or do you mean no response from the meter?

73,

Bill KU8H

On 09/24/2018 02:26 PM, Richard Seguin wrote:
Hi Chris,

Thank you for passing this along. I am getting 50M ohm between 2 and 3 and
nothing on the reverse. The other pins yield similar results. I get values
that are way off the mark or none at all.

I'll keep them around until I can get a good batch and I'll see how they
compare, for now, I'm marking them as being counterfeit.

Richard (VE9IT)

On Mon, Sep 24, 2018 at 1:52 PM Chris Smith <me@m0xte.uk> wrote:

Hi,

Quick update on this. I was contacted off list with measurements on
another NE602AN. If you swap the probes round on pin pairs 1,3 and 2,3
this drops to around 4.7M so clearly this is activating a semiconductor
junction inside the device.
7 -> 3 = 25k 1 -> 3 = 9.86M ohms 2 -> 3 = 9.73M ohms 6 -> 4 = 19.5k 6
-> 5 = 19.5k
That should be enough to do a simple red/green test on a 612/602 to see
if it is actually one or not.
Many thanks to the additional contributor :)

Best regards,

Chris Smith M0XTE

On Sun, 23 Sep 2018, at 20:56, Chris Smith wrote:
Sounds like they are hooky. This is happening very frequently with
popular parts. Get one out and measure the following with a DMM
on ohms.> From the datasheet there should be the following approximate
resistances> between the pins:
7 -> 3 = 25k
1 -> 3 = 1.5k
2 -> 3 = 1.5k
6 -> 4 = 19.5k
6 -> 5 = 19.5k

If all of these are vastly off then it's probably not a 612.

Finding out what it really is could be interesting :)

Best regards,

Chris Smith M0XTE


On Sun, 23 Sep 2018, at 20:51, Richard Seguin wrote:
Hello folks,

I'm experiencing a very fishy situation with a batch of NE612AN
double> balanced mixers that I got from China. When I apply power to>>
the correct> pin (I verified several times) they get really hot to
the touch.>> I created> a test circuit that is similar to what the
datasheet
specifies for an> unbalanced input, and I have also played around
with using a crystal>> oscillator instead of the DDS output that I
wanted to use.

I'm not looking for anyone to troubleshoot my circuit, I'm
more or less> curious if anyone else ran into symptoms like
this. I'm>> suspecting that> what I have may not be SA612AN mixers,
and that I am
applying>> power to the> incorrect pins.

If anyone has one of these laying around, what happens when you
apply VCC> (5V) to pin 8 and GND to pin 3? Does the IC heat up?

Richard (VE9IT)







--
bark less - wag more


Richard Seguin
 

No response from the meter, so not a dead short.

On Mon, Sep 24, 2018, 5:52 PM Bill Cromwell <wrcromwell@gmail.com> wrote:

When you say 'none at all' do you mean zero ohms or do you mean no
response from the meter?

73,

Bill KU8H

On 09/24/2018 02:26 PM, Richard Seguin wrote:
Hi Chris,

Thank you for passing this along. I am getting 50M ohm between 2 and 3
and
nothing on the reverse. The other pins yield similar results. I get
values
that are way off the mark or none at all.

I'll keep them around until I can get a good batch and I'll see how they
compare, for now, I'm marking them as being counterfeit.

Richard (VE9IT)

On Mon, Sep 24, 2018 at 1:52 PM Chris Smith <me@m0xte.uk> wrote:

Hi,

Quick update on this. I was contacted off list with measurements on
another NE602AN. If you swap the probes round on pin pairs 1,3 and 2,3
this drops to around 4.7M so clearly this is activating a semiconductor
junction inside the device.
7 -> 3 = 25k 1 -> 3 = 9.86M ohms 2 -> 3 = 9.73M ohms 6 -> 4 = 19.5k 6
-> 5 = 19.5k
That should be enough to do a simple red/green test on a 612/602 to see
if it is actually one or not.
Many thanks to the additional contributor :)

Best regards,

Chris Smith M0XTE

On Sun, 23 Sep 2018, at 20:56, Chris Smith wrote:
Sounds like they are hooky. This is happening very frequently with
popular parts. Get one out and measure the following with a DMM
on ohms.> From the datasheet there should be the following approximate
resistances> between the pins:
7 -> 3 = 25k
1 -> 3 = 1.5k
2 -> 3 = 1.5k
6 -> 4 = 19.5k
6 -> 5 = 19.5k

If all of these are vastly off then it's probably not a 612.

Finding out what it really is could be interesting :)

Best regards,

Chris Smith M0XTE


On Sun, 23 Sep 2018, at 20:51, Richard Seguin wrote:
Hello folks,

I'm experiencing a very fishy situation with a batch of NE612AN
double> balanced mixers that I got from China. When I apply power
to>>
the correct> pin (I verified several times) they get really hot to
the touch.>> I created> a test circuit that is similar to what the
datasheet
specifies for an> unbalanced input, and I have also played around
with using a crystal>> oscillator instead of the DDS output that I
wanted to use.

I'm not looking for anyone to troubleshoot my circuit, I'm
more or less> curious if anyone else ran into symptoms like
this. I'm>> suspecting that> what I have may not be SA612AN mixers,
and that I am
applying>> power to the> incorrect pins.

If anyone has one of these laying around, what happens when you
apply VCC> (5V) to pin 8 and GND to pin 3? Does the IC heat up?

Richard (VE9IT)







--
bark less - wag more