EMRFD Message Archive 10559

Message Date From Subject
10559 2014-12-10 07:43:46 richj_focus What if all throuhg hole went obsolete ??
Hello:

So if all through hole transistors went obsolete which set of them would you want to continue building radios without using SMD?

I am just looking at building up inventory as get into building and i would like to stick with through as long as possible.

Thanks you
rich


10560 2014-12-10 08:46:02 Tayloe, Dan (NSN ... Re: What if all throuhg hole went obsolete ??

I would want BS170s.  Rated 700 mW power dissipation with a typical 1.2 ohm DS on resistence.  Two or three of these running class “E” work very well as a CW 5w QRP final.

 

I have been waiting for this to show up in SMT form with a tiny tab to retain the 830 mW.  The current SMT part, MMBF170, is only good for 300 mW.  Three of those would be good for only 2w.

 

There just is not much industry excitement for producing a better $0.15, 1w, low input “C” MOSFET SMT part that switches very fast.

 

-          Dan, N7VE

 

10561 2014-12-10 10:17:07 Cecil Bayona Re: What if all throuhg hole went obsolete ??
That is a reason why on my store I have stocked up and continue to do
so on decent Silicon Transistors, most I have 5,000 or more on stock,
mind you I like SMD but many don't so I'm starting to get SMD devices.

Still the writing is on the wall so one best start heading in that
direction, SMD projects are not as hard as people think it is, using
soldering paste I can do a board much faster than with lead
components and I don't have great eyesight.


At 09:43 AM 12/10/2014, you wrote:
>
>
>Hello:
>
>So if all through hole transistors went obsolete which set of them
>would you want to continue building radios without using SMD?
>
>I am just looking at building up inventory as get into building and
>i would like to stick with through as long as possible.
>
>Thanks you
>rich
>

--
Cecil - k5nwa
< http://thepartsplace.k5nwa.com/ > < http://www.softrockradio.org/ >

Never take life seriously. Nobody gets out alive anyway.
10562 2014-12-10 11:00:34 Thomas S. Knutsen Re: What if all throuhg hole went obsolete ??
Well, since 90% of what I do is in SMD, here is my list of semiconductors I often use:
LL4148 diode
BAT54 (detectors and such)
BC847 (General purpose NPN)
BC857 (General purpose PNP)
MMBTJ310 (J-FET J310)
NE46134 (500mW driver, post mixer amp)
BF994 (dual gate mosfet)
BFQ17

These cover most of the things I do at HF and low VHF. Then there are more spesific things like MMIC's and microwave diodes and such. Most, if not all of the components with wires that you use are avaible in one or several SMD packages. Some times they will have a bit different part number, like MMBT3904 instead of 2N3904. The power rating will usualy be a bit lower, so make sure to substitute with care. 

Perhaps the most important part is a couple of kits of assorted resistors and capacitors. Filling these with good quality components from an well know supplier is important, several of the chinese kits have had SMD capacitors with Q below 1000 and resistors with parasitic capacitance all over the place. 

I do prototyping with SMD by sketching a simple layout on regular (5mm or 1/4") grid ruled paper, an passive component then uses  2 grids for each terminal, and the semiconductor legs needs one grid each. That way, I get a simple sketch to fit to a pice of PCB with some ligth glue. Then I cut out the layout with a dremel. This way I quickly get a small board for what I prototype, most of the time there will be several alternations to the layout, component choise and such. When the circuit is prototyped and working as expected, i order in boards from OSH park or one of the chineese suppliers. 

73 de Thomas LA3PNA.


2014-12-10 16:43 GMT+01:00 richj45@gmail.com [emrfd] <emrfd@yahoogroups.com>:
 

Hello:

So if all through hole transistors went obsolete which set of them would you want to continue building radios without using SMD?

I am just looking at building up inventory as get into building and i would like to stick with through as long as possible.

Thanks you
rich


10563 2014-12-10 11:35:21 blumu Re: What if all throuhg hole went obsolete ??
I and my retinas are getting scared. Which UK suppliers of
three-or-four-legged transistors are recommended for stock-up ?

Michael

----- Original Message -----

>So if all through hole transistors went obsolete which set of them
>would you want to continue building radios without using SMD?
>
>I am just looking at building up inventory as get into building and
>i would like to stick with through as long as possible.
10564 2014-12-10 14:52:17 Chris Howard w0ep Re: What if all throuhg hole went obsolete ??
Thomas,

I would like to see a video or some pictures of how you do your SMD layout.
Sounds very useful!



10565 2014-12-10 15:13:20 kc7nj Re: What if all throuhg hole went obsolete ??
Thomas,  I too would like to see your method.  Dave  K2ZU
10566 2014-12-10 15:20:52 Thomas S. Knutsen Re: What if all throuhg hole went obsolete ??
Ok, I will try to make an small video and upload to youtube, failing that, I will take some picures and do an writeup. 
I will try to get it done during this week, but the workload is a bit high at the moment. 


73 de Thomas LA3PNA.


2014-12-11 0:13 GMT+01:00 kc7nj@yahoo.com [emrfd] <emrfd@yahoogroups.com>:
 

Thomas,  I too would like to see your method.  Dave  K2ZU

10567 2014-12-10 15:45:13 Chris Howard w0ep Re: What if all throuhg hole went obsolete ??
My least favorite thing about making circuit boards is the drilling.
I do OK with the etching (one side only). Manhattan works OK.
SMD would be cool.

And, if anyone has a pointer to a kit of resistors and capacitors
that are recommend, I would be interested in that. The through hole
capacitor kit from NorCAL was a big win when I bought it years ago.
And I've been able to manage on Radio Shack resistor kits.

Chris
w0ep


10568 2014-12-10 16:34:26 kc7nj Re: What if all throuhg hole went obsolete ??
Thanks,  I'm  looking forward to it.   Dave  K2ZU
10569 2014-12-10 16:37:37 Gene W5DOR Re: What if all throuhg hole went obsolete ??

I purchased these SMD capacitor and resistor kits and they will probably keep me supplied for the rest of my life.  I got the larger 1206 size so I could handle the soldering ok with my poor eye sight.

 

Resistors:   SMD size 1206 

 

http://www.ebay.com/itm/SMD-Resistor-Assorted-Book-kit-1206-5-50-x-86-values-4300pcs-/221081249142?pt=LH_DefaultDomain_0&hash=item3379782576

 

Capacitors:  SMD size 1206

 

http://www.ebay.com/itm/SMD-Resistor-Assorted-Book-kit-1206-5-50-x-179-values-8950pcs-/221081249020?pt=LH_DefaultDomain_0&hash=item33797824fc

 

 

Gene, W5DOR

gene@w5dor.com

www.w5dor.com

 

 

 

 

 

 

10570 2014-12-10 17:13:53 ad7jt Re: What if all throuhg hole went obsolete ??

Here’s some I recently bought.  They are a little unique in that they are packaged in baggies instead of cut pieces of tape.  For me, that is more convenient.  I bet most of the SMD parts that are lost are lost as they are cut out of the tape.

 

Resistors:

 

http://www.ebay.com/itm/Free-Shipping-170-Value-0805-SMD-Resistor-Kit-0R-10MR-1-8W-5-8500pcs-RoHS-/301378133009?ssPageName=ADME:L:OU:US:1120

 

Capacitors:

 

http://www.ebay.com/itm/50-Value-0805-2012-SMD-Ceramic-capacitor-1pF-10uF-MLCC-SMT-KIT-2500PCS-/291316425934

 

 

73,

Dave Collins – AD7JT

 

 

 

10571 2014-12-10 17:29:52 Ronan McAllister Re: What if all throuhg hole went obsolete ??

Gene et-al,

I know offshore manufacturers can produce any quality components required; these look interesting but I wonder if you or anyone here has done any spot checking on these snd similar smd cap kits from this ebay or other seller ( tempo for tuning np0/c0g, this would require an environmental chamber and rather complex equipment of course or ingenious altetnatives) as well as basic checks -room temp capacitance value tolerance etc).

On a related subject (back to earth keeping my near-retirement budget in mind) does anyone have any feedback on the LCR meters you see so many of on eBay (those suited for HF frequencies)?

I ran into one this AM it looks a little better than the typical $25 models at least this one uses a few different test frequencies :

Ebay    Item Number

171199475262

Thanks for any feedback.  Typeos courteosy of Android





10572 2014-12-10 23:15:12 farhanbox@gmail.c... Re: What if all throuhg hole went obsolete ??

is there any supplier of marked smd caps?

------ Original message------

10573 2014-12-10 23:43:42 Gene W5DOR Re: What if all throuhg hole went obsolete ??

These 1206 size smd capacitors in the kit (book) are all marked with their value.  I have a magnifying glass on the bench so I can read the values as marked.   I think the 1206 size is plenty large for markings.   Some of the SMD caps that are much smaller may not be marked   and then some SMD manufacturers may not mark them   but those I purchased (see URL below) were clearly marked.

 

However,  i also wanted a smaller supply of NPO smd caps.  I purchased a kit from   www.aidetek.com   and they are not marked.  So I guess some are and some aren't. 

The one's (non-NPO) from sun-pec.com that I listed the URL for below are marked and as near as I can tell the manufacturer is Yageo    http://www.yageo.com/NewPortal/_en/index.jsp

 

Gene, W5DOR

gene@w5dor.com

www.w5dor.com

 

 

 

10574 2014-12-11 06:59:44 Thomas S. Knutsen Re: What if all throuhg hole went obsolete ??
As promised, here is a video of my method of prototyping with SMD's.

73 de Thomas LA3PNA.

2014-12-11 0:20 GMT+01:00 Thomas S. Knutsen <la3pna@gmail.com>:
Ok, I will try to make an small video and upload to youtube, failing that, I will take some picures and do an writeup. 
I will try to get it done during this week, but the workload is a bit high at the moment. 


73 de Thomas LA3PNA.


2014-12-11 0:13 GMT+01:00 kc7nj@yahoo.com [emrfd] <emrfd@yahoogroups.com>:

 

Thomas,  I too would like to see your method.  Dave  K2ZU

10575 2014-12-11 07:23:05 Lee Hiers Re: What if all throuhg hole went obsolete ??
10576 2014-12-11 07:31:12 Chris Howard w0ep Re: What if all throuhg hole went obsolete ??
Very nice video!
Thanks for doing that, very helpful.

Chris
w0ep



10577 2014-12-11 08:48:09 Cecil Bayona Re: What if all throuhg hole went obsolete ??
That is a pretty interesting way to make a
circuit board specially a quickie board to try
out something quickly. No heating, transferring, or chemicals fumes.

At first I was not pleased with the way you were
drawing the board but then when you got out the
Dremel tool then it all made sense. How large a
board have you made using this way of doing PCBs?

I recently went to the Wal-mart art section to
get a gift and I noticed they had grid paper of
various sizes for not much money, I will need to
get some next time I go there so I can try it
out, my Dremel Tool is itching to be used. I have
a nice collection of SMD 1206 resistors and
capacitors but this will work with component
leads also since it's basically a Manhattan PCB with no glue.

At 08:59 AM 12/11/2014, you wrote:
>
>
>As promised, here is a video of my method of prototyping with SMD's.
><http://youtu.be/qdc9N2Hags8>http://youtu.be/qdc9N2Hags8
>
>73 de Thomas LA3PNA.
>
>2014-12-11 0:20 GMT+01:00 Thomas S. Knutsen
><la3pna@gmail.com>la3pna@gmail.com>:
>Ok, I will try to make an small video and upload
>to youtube, failing that, I will take some picures and do an writeup.Â
>I will try to get it done during this week, but
>the workload is a bit high at the moment.Â
>
>73 de Thomas LA3PNA.
>
>2014-12-11 0:13 GMT+01:00
>kc7nj@yahoo.com>kc7nj@yahoo.com [emrfd]
><emrfd@yahoogroups.com>emrfd@yahoogroups.com>:
>
>Thomas,  I too would like to see your method. Dave  K2ZU

--
Cecil - k5nwa
< http://thepartsplace.k5nwa.com/ > < http://www.softrockradio.org/ >

Never take life seriously. Nobody gets out alive anyway.
10578 2014-12-11 08:59:21 Clint Re: What if all throuhg hole went obsolete ??
That process works very good.  I use my Harbor Freight mill to make circuits boards.  I can precisely control the depth of the cut through the copper foil, the width of the cuts, etc.  The only downside that I have found is that all of the cuts need to be straight lines – unless you have a very steady hand on making curved lines.
 
73
Clint
W7KEC
 
10579 2014-12-11 09:18:18 Ronan McAllister Re: What if all throuhg hole went obsolete ??

Sometimes I run into surplus auctions and get strips of L & Cs unmarked.  I have a box of such devices to test with no markings or cryptic codes.  For those and general testing I may look into these if THE "SMH codebooks" you find googling doesn't help:

http://www.smarttweezers.ca/

Anyone who has used these in real world please ping..

Thx
Kb6nhq

10580 2014-12-11 12:31:45 arfghans Re: What if all throuhg hole went obsolete ??
The Dremel tool method is great. I like your design process; it's much like laying out any circuit board.  I start by cleaning the board, then write directly on it with a fine-point Sharpie. Then I use a very fine-pointed conical carbide bit (Dremel #9909), and trace over the lines with that. I can make curves if needed, and some rather small features on the order of 50 mils wide. The skinny cutter also allows me to alter the board after parts are mounted, since I can sneak in between things.  I've also found it very useful to tin all the pads before installing any parts. Projects built this way are small, very robust, and typically suitable for UHF and even some microwave work.

Gary, NA6O
10581 2014-12-11 13:32:05 Kirk Kleinschmidt Re: What if all throuhg hole went obsolete ??
Very helpful video. Thanks!

I wonder if a guy could use precisely cut manhattan squares, bridging the gaps with large-size smt parts?

I'd guess that there's a bit more stray C doing it that way, but at HF it may not be a problem?

Anyone do this?

Thanks,

--Kirk in MN


My book, "Stealth Amateur Radio," is now available from
www.stealthamateur.com and on the Amazon Kindle (soon)
10582 2014-12-11 13:57:43 Thomas S. Knutsen Re: What if all throuhg hole went obsolete ??
Remember that SMD components are quite fragile since most of them are made from ceramics. I tried the method, and mounted some capacitors between the ground plane and a pad, but if there was any movement of the pad, the capacitor would break. 
I suppose if one glues the pad, that could be a worthwile experiment. I tend to not glue as I always gets glue where I want to solder, and then the solder won't stick and eyes hurt.

73 de Thomas LA3PNA.

2014-12-11 22:32 GMT+01:00 Kirk Kleinschmidt sohosources@yahoo.com [emrfd] <emrfd@yahoogroups.com>:
 

Very helpful video. Thanks!

I wonder if a guy could use precisely cut manhattan squares, bridging the gaps with large-size smt parts?

I'd guess that there's a bit more stray C doing it that way, but at HF it may not be a problem?

Anyone do this?

Thanks,

--Kirk in MN

My book, "Stealth Amateur Radio," is now available from
www.stealthamateur.com and on the Amazon Kindle (soon)

10583 2014-12-11 14:02:27 kc7nj Re: What if all throuhg hole went obsolete ??
Thanks for the video,  that was just what I wanted to see.   Dave  K2ZU
10584 2014-12-11 14:13:17 Tayloe, Dan (NSN ... Re: What if all throuhg hole went obsolete ??
I too have miserable experiences with"self supporting" deadbug smt caps mounted vertically from copper ground into the air.  With the other end connected to #32 enamel wire (my preferred hookup wire for most interconnections), the cap would often snap in half.  Bridging a Manhattan pad to ground was never a problem.

SMT resistors I have found to be very rugged. However I have on occasion have destroyed the end pad trying to reuse a $0.01 part.

- Dan, N7VE

Sent from my Windows Phone

10585 2014-12-11 16:47:47 bob_ledoux Re: What if all throuhg hole went obsolete ??
Dan, I thought you preferred ugly for your prototyping.  Are you still depending on leaded components? 

I like Manhattan for proto work, but this means I need daughter boards for the SMT IC's.  I've also not developed a good technique to use 0805 chips in Manhattan.

Paul Harden, NA5N has a primer on SMT Manhattan:
http://www.aoc.nrao.edu/~pharden/hobby/HG-MANHAT2.pdf

But it requires very precise placement of pads to bridge simple components. My super glued pads tend to suffer from sloppy placement.  Leaded components allow for more error in pad placement.

Using SMT means I etch boards for my SMT prototypes.  I use longer traces to permit cutting traces and adding jumpers for circuit improvement.

73, Bob, N7SUR
10586 2014-12-11 16:58:41 Phil Sittner Re: What if all throuhg hole went obsolete ??

Gentlemen-
 
I got started using SMD after having a conversation with Wes, W7ZOI,and have tried a variety of approaches. The best of these is to sketch out a simple design on graph paper and then use a machinists digital caliper (available at Harbor Freight) to scribe lines on the copper clad material. Once the lines are scribed, an Exacto knife is used to cut the straight traces. It's fast, accurate and very straight forward. Some of you may wish to give it a try. Good luck, and happy experimenting.
 
Phil
kd6rm
----- Original Message -----
10587 2014-12-11 17:33:42 Tayloe, Dan (NSN ... Re: What if all throuhg hole went obsolete ??

I prototype with what I have on hand.  I love using deadbug using SOIC (0.05”) ICs and actually prefer them as the circuit is much more compact.  The 0.1” spacing of DIPs are huge.  The 0.05” spacing of SOIC is quite reasonable.  A normal DIP now seems wasteful in space.  With SOIC ICs, I find that 1/8th watt resistors are a good deadbug match.  I have quite a stock of 1/8th watt resistors, but sometimes switch to 1208/0806 resistors if I don’t have the right 1/8th watt resistor on hand.

 

The TSSOP (0.02’?) are getting painful.  I once did deadbug with a pair of 9851’s which are TSSOP. I had to bend the pins in alternate directions such as odd inward and even outward, using #32 wire as hookup.  Unfortunately, TSSOP ICs have fragile pins that can break off if bent too much.  I once ruined a 9851 by breaking off a pin.  TSSOP are not my preference in deadbug, but it is getting harder to find SOIC sized packages.

 

When mixing leaded parts with SMT Rs and Cs, you can simply tack a SMT cap or resistor to a flying lead of a transistor (for example) and they are fine. SMT caps only seem to have a breakage problem if one end is firmly anchored, such as soldered to ground. 

 

0806 is not hard to work with.  Smaller than that gets harder.  I have bought 0402 LEDs and attached #32 wire to each end for use in some of my son’s models.  That required a bit more determination than normal.  He now is very proficient at doing that himself. These 0402 LEDs tend to be all but invisible until they light up.  Even when turned on, they are more a pinpoint light source rather than a visible part. 

 

Light from “nothing”.  That is a very cool effect.

 

-          Dan, N7VE

 

10588 2014-12-12 02:11:21 bubnikv Re: What if all throuhg hole went obsolete ??
This is very much the same technique I use, only I am unable to finely control the dremel. I rather cut the traces with a sharp needle file. It is more labor intensive, but I have finer control and I am able to build quite tiny stuff, see the following pictures of an active antenna:

 

http://ok1iak.blogspot.cz/2013/10/active-ferrite-rod-antenna-by-oh7sv.html

 

And yes, I have a bad experience with the SMD caps as well. The last time I soldered a BNC socket into the printed board and soldered one leg of a SMD capacitor to the center of the BNC socket. I had two of them, both broke once I connected and disconnected the BNC connector couple of times.

73, Vojtech OK1IAK
10589 2014-12-12 04:09:37 jorschei Re: What if all throuhg hole went obsolete ??

Hi all,

For a new design where TSSOP and SSOP, MSOP chips must be used I design in "Sprint Layout 6.0" small adapter PCB to a DIL 0.1 inch format. Factory made little PCB DIL plug in modules make it possible to experiment in an  easy way.  And if the chip is defect or must be replaced I can plug in a new one without throw  a way the whole designed PCB  RX/TX motherboard PCB.

I cut an new experimental design in small functional modules work them out in schematic and make a modular functional PCB module design. Testing the module and plug them on the RX or TX board. It is more work bud it keeps the quality of the RX/TX project.   See the adapter  example  modul  in the PE1KTH   file  

73' Joris  PE1KTH    

10591 2014-12-12 05:49:41 Chris Howard w0ep Re: What if all throuhg hole went obsolete ??
that sounds very slick! Would you have any pictures
or video?



10592 2014-12-12 07:02:42 Richard Johnson Re: What if all throuhg hole went obsolete ??
Dan:

So what kind of #32 wire do you use?
And were to get it?

rich
10593 2014-12-12 07:52:24 Tayloe, Dan (NSN ... Re: What if all throuhg hole went obsolete ??

I used normal enamel wire and tend to use either #32 or #30 (it depends on which roll is close at hand at the moment) as most connections carry relatively little current. I might use larger #28 for finals, drivers for the finals, power to regulators, and higher power audio output ICs. It is very easy to burn the enamel off the end of the wire (both #28 and #32) by placing the cut end (bare copper) into a solder blob on the iron.

 

A 1 lb roll of #32 is about 5000 ft.  Thus even 2 or 4 ounces of wire is more than you need.

 

I think most of the enamel wire I have on hand is Beldon.  You do **not** want to use the special high temperature type!

 

The wire (“magnet wire”) is expensive from Mouser, but seems **much** cheaper on eBay.  Search for “magnetic wire 32” and look for the 155 C type rather than the higher temperature 200 C insulation as the 155 C should be easier to burn off the insulation.

 

-          Dan, N7VE

 

10594 2014-12-12 10:40:28 Todd F. Carney / ... Re: What if all throuhg hole went obsolete ??
SchmartBoard.com specializes in SMT-to-DIP adapters--little pcbs--for just about every SMT footprint. Some of their boards have grooves that make aligning the SMT device on its pads very easy. 

There's probably other outfits that sell something similar (Sparkfun? Adafruit?).
 
73,

Todd
------------------------------------------------------------------------------------
K7TFC / Medford, Oregon, USA / CN82ni / UTC-
8
 (P
​S
T)
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10595 2014-12-12 10:52:18 Phil Sittner Re: What if all throuhg hole went obsolete ??

Chris-
 
I put together a document describing the technique but it's too large to send through the group forum. Give me your email address and I'll send it directly to you.
 
Phil
----- Original Message -----
10596 2014-12-12 11:42:51 Chris Howard w0ep Re: What if all throuhg hole went obsolete ??
Thanks!

w0ep@w0ep.us

You might consider posting it to the group's files section.

Chris


10597 2014-12-12 12:24:12 kerrypwr Re: What if all throuhg hole went obsolete ??
Futurlec has a range of adaptor PCBs for SMD packages;

http://www.futurlec.com.au/SMD_Adapters.jsp

Futurlec is an Australian-owned company in Malaysia; I have found their service fast & reliable.

Kerry VK2TIL.

 

10601 2014-12-12 21:25:52 bellettau Re: What if all throuhg hole went obsolete ??
Apart from  TSSOP parts, one can build a pretty tidy Proto using most SMD parts using the 0.1" grid PCB's available on eBay in packs of four sizes usually. eg
eBay item number:
261524218025
(Search "PCB" on eBay for other sizes)

0805 parts can be fitted from hole to hole, SOT-23 parts can be angled across three pads and of course, through hole parts can also be fitted as they are plated through PCB's. SOIC parts can be fitted using the leg up/down technique and wires.
Interconnecting sections, power supplies etc with wire wrap wire, stripped of insulation.

For the TSSOP parts, use the adapter PCB's mentioned in this thread and plug/socket on 0.1" pitch.

glenn
vk3pe
10603 2014-12-14 11:00:57 kb1gmx Re: What if all throuhg hole went obsolete ??
My collection of through hole part will then finally be worth something.  ;)

I use SMT in increasing amounts.  They just work for me.

Allison

10604 2014-12-16 10:15:12 iq_rx Re: What if all throuhg hole went obsolete ??
There are other options with related performance.  Antique Electronic Supply has a half dozen different current manufacture dual FETs, type 12AX7.  They generally require higher power supply voltages than J310s, and enable the channel using a thermal mechanism with independent leads rather than a doped semiconductor.  The complete absence of minority carriers simplifies device physics a bit, but the SPICE models are fairly similar.  Really high impedance inputs facilitate high Q RF tuned circuits, and low-pass networks from high impedance to 50 ohms greatly simplify harmonic issues while providing selectivity for narrow band applications.  Matched sets in the same package make nice diff pairs.

An experimenter using what we've learned in the past 40 years could do some elegant, simple, and very high performance single-band radio gear that could use even draw less power than the usual modern rigs running digital hardware.  One of my more advanced students has been experimenting with differential pairs of EL84s at low frequency and a Doherty linear amplifier using GaN devices at 3.5 GHz in the past year.

Just figure out what kind of active devices and passive components are readily available, and design experimental gear with what you can get.  That's in the spirit of both EMRFD and Wes and Doug's earlier work introducing design with what is now half-century-old silicon technology to the radio community.

Enjoy the experiments,

Rick KK7B