To the Moon with Only Stone Tools and Bear Skins Technology

Today is 20 July 2015. 

On this day many, many summers ago in 1969,  I sat transfixed to my family's  B&W TV.  There was no actual video from the space craft landing on the moon it simply was not available.  The TV Screen showed an animation and a digital countdown timer was all that their was to see.  Even at my young age I understood there was a drama unfolding a quarter of a million miles away...

As they descended to the lunar surface, mysterious alarms were being called out "1202, 1201, 30 seconds"  of fuel left...a real nail biter..

102:38:26 Armstrong: (With the slightest touch of urgency) Program Alarm
102:38:28 Duke: It's looking good to us. Over.
102:38:30 Armstrong: (To Houston) It's a 1202.
102:38:32 Aldrin: 1202. (Pause)

...1202 Alarm! what the hell is that? Oh no! this can't be good....

102:38:53 Duke: Roger. We got you...(With some urgency in his voice) We're Go on that alarm.

More routine communications stuff then...

102:42:19 Aldrin: Program Alarm. (Pause) 1201
102:42:24 Armstrong: 1201. (Pause)
 102:42:25 Duke: Roger. 1201 alarm. (Pause) We're Go. Same type. We're Go.

I am pretty sure i said "oh no!" at this... I knew that anything called an "ALARM" can't be good....two ALARMs is really bad. Here is how the rest went...

102:44:04 Aldrin: I got the shadow out there.
102:44:07 Aldrin: 250 (feet altitude), down at 2 1/2, 19 forward. (Pause)
102:44:13 Aldrin: Altitude (and) velocity lights (on).
102:44:16 Aldrin: 3 1/2 down, 220 feet, 13 forward. (Pause)
102:45:17 Aldrin: 40 feet, down 2 1/2. Picking up some dust.
102:45:21 Aldrin: 30 feet, 2 1/2 down. (Garbled) shadow
102:45:25 Aldrin: 4 forward. 4 forward. Drifting to the right a little. 20 feet, down a half.
102:45:31 Duke: 30 seconds (until the 'Bingo' call).

...Now they are running out of Fuel!

102:45:32 Aldrin: Drifting forward just a little bit; that's good. (Garbled) (Pause)
102:45:40 Aldrin: Contact Light.
102:45:44 Aldrin: Okay. Engine Stop.
102:45:47 Aldrin: Mode Control, both Auto. Descent Engine Command Override, Off. Engine Arm, Off. 413 is in.
102:45:57 Duke: We copy you down, Eagle.

They did it?

102:45:58 Armstrong (onboard): Engine arm is off. (Pause) (Now on voice-activated comm) Houston, Tranquility Base  here. The Eagle has landed.

 ...Yes!

102:46:06 Duke: (Momentarily tongue-tied) Roger, Twan...(correcting himself) Tranquility. We copy you on the ground. You got a bunch of guys about to turn blue. We're breathing again. Thanks a lot.

102:46:16 Aldrin: Thank you.



You can google and read the entire  Apollo 11 Landing Transcripts  But this is not the real point of this post... it is really about:

The Apollo Guidance Computer

How did they do it?  What was this mysterious box producing these cryptic alarm numbers?   How in the hell can you navigate and land on the moon with a computer with less "computing power" than a digital watch?

First of all, it is not less computing power.  After some research (yes, I'are a Google Scholar)  it was a pretty cool bunch of transistors and probably the first digital display in any aerospace machine till that date.  And...

I want to build one!

 

Spock: Captain, I must have some platinum. A small block would be sufficient, five or six pounds. By passing certain circuits through there to be used as a duo-dynetic field core...

Capt. Kirk: [interrupting] Uh, Mr. Spock, I've brought you some assorted vegetables, baloney and a hard roll for myself, and I've spent the other nine tenths of our combined salaries for the last three days on filling this order for you. Mr. Spock, this bag does not contain platinum, silver or gold, nor is it likely to in the near future.

Spock: Captain, you're asking me to work with equipment which is hardly very far ahead of stone knives and bearskins.

For my stone tools, the challenge is to make a 1960s vintage machine from about the same vintage (ca. 1979) parts.  Impossible you say?  Yes, well, almost.  Here is my stone tool:

 

 

 This is a RCA COSMAC 1802 microprocessor I built, actually the 3rd one but using parts from the first two  (yes, in my parents basement) ca. 1977 - 1979.  I know this because the notebook it is sitting on has the dates and parts orders, plus notes and other useful information. 

This old machine had been sitting in my garage for at least the last 15 years and other storage for the last 4 decades.  After a little cleaning, replacement of the little red push button that had corroded, some wires, and one LED...it actually still worked!

Reality Bites...

Being able to re-write the entire AGC software is an undertaking that would take years, and require understanding of all the equations and NASA documentation. Not going to happen as a past time.

The second option  is: can this machine run the actual code?  Well, maybe. But a quick mental calculation; it will take perhaps 10 - 100 COSMAC instructions to make each AGC instruction. These two machines run at approximately the same speed ( 2MHz) so the result will be 10 - 100x slower and take that much more memory.

OK so there is a third option...how about just the display?  It would make a nifty looking clock. 

The DSKY!

Beautiful, is it not?   The epitome of  1960's computing user interface technology. 

...Is it just me - or do these displays look like a couple of smart phones?

I wont put all the details here, they are in my  GITHUB. repository.  You an go there and study the details if you like.  It is a work (?) in progress but it really is just a fun diversion project.  There is no real need for us old assembly language programmers anymore - i still do enjoy low-level programming, just something to keep my old brain's spark plugs going a while longer - kind of the geek equivalent to a crossword puzzle.   Here is an early version...it really is just a VIP Clock with the digits re arranged to look like V16N65  The mission elapsed time on the DSKY, the current version is a working proto.:

I may add some more here as i plan to make a second version that does not only time, but navigation ( tied to an old Garmin 12 GPS) and some inertial navigation system measurements (Gyroscope).  This will be a cool addition to my 1960's vintage Dune Buggy eh?

As for running the actual code?  Oh - I think the current ARM boards such as Raspberry Pi could pull it off.

As we like to say on the Rad Ranchero:

~Stay Tuned! ~

...and happy birthday pop - where ever you are! we miss you down here on earth.

Which Way are you going?

Yeah, I know, Steve get a new car.  The 2001 Ford Escape that me and my assistant replaced the head lights on. Was that really 3 years ago?  We had to pull out the tools and see to fixing the driver side turn signal lamp.

 Old Post Headlamp Post

No big deal?  Well answer this; how many tools does it take to replace a turn signal lamp on a 2001 Ford escape?

Yeah, the only light on the car that is likely to get you a ticket, the owner's manual states; "...bring to qualified service technician or dealer to replace"  So i guess now that I am a qualified technician? 

Side nut...exposed

The painful thing about this vehicle is some of the lamps nuts and bolts are behind those plastic fenders held on with the push clips.  You can't simply un-screw them, you have to pry them out.

For this new effort, i decided to forgo the screw driver and needle nose method to breaking them off and this time got a new tool!  The new red handled tool is: S & G Tool - Upholstery Clip Removal Tool Part # 87810 There are some fancy pliers types, they just did not have in stock so I got this on and it worked like a champ.

Lower Nut ... is here

The whole head lamp assembly must be puled out just to reach the sockets!

Almost There!

I did not break any this time but went ahead and replaced all 6. I had to buy a 6 pack when i stopped by the auto parts store so I would have a spare just in case.  Since I would just loose them or get a new car before i have to do this again, i replaced all 6 with new clips! ( BTW -  all the broken ones from before had already been replaced)



Target located!

 

The old bulbs had quite a bit of  the enamel paint peeling off so i would have had fancy white turn signals shortly...

 

Fuzzy old bulb

New and shiny...

New!

Plastic things were easy as:

One...

...Two...

...Three!



 

Back together with a push ( x6)  and good as new.  I never got a picture of the tool in action, it went so fast, just slip behind and pry out less than 10 seconds they were pretty much done.  It took at least a minute with the pliers and I broke the clips anyway.  So are these mundane project blog stories pointless?  Well,  I guess the point of this story is;

 

Buy the tool, and plastic fasteners, when you pick up the turn signal bulbs.

..and the second point: there are two bulbs in a pack so replace them!  I did both.


My assistant was a little tired after all the bunny guard duty he performed this morning but will be ready for the next project!



Tired Boy

~ ~ ~

BTW I got behind on blogging some projects, work and business travel to China got in the way... and i never can remember which phone/camera i documented the progress with.  I'll release more drafts when I clean them up a bit!

 

Hustler 4BTV 4-Band HF Vertical Antenna

CAMP HF ANTENNA

We have a remote desert camp that go to when the weather is nice and play with radios.  It is a pretty quiet spot both solitude and radio -wise. ( when the dune buggies are not running around)

Several years, at least a decade ago, On a camping trip here I convinced my nephew Nick there may be gold in the ground at about this spot.  We proceeded to dig a 6 foot-deep hole and when we got to the bottom, I put in the 8 foot pole that is the support for this antenna and put all the sand and rocks back in it. I got the Hustler antenna from a ham club swap meet for $20 years earlier. It had been in service since the late '70s.  Finally we dug some trenches and strung some tuned radials under the sand in all directions. They have been here ever since that day.

I used this antenna for many years.  I never really took it down as this spot is so remote and nobody ever bothered it ...until last summer.

[bent antenna]

Mother nature had some fun one summer afternoon.  I am not sure what kind of storm it was, the desert tends to get some violent thunderstorms in the summer as a monsoonal flow sets up from the warm waters of the Sea of Cortez inside of the Baja peninsula.  In any case this storm left lots of sand sticking to the sides of the buildings poles and trailers so it guess that the force of the wind plus the mass of the rain and sand was too much for this 35-year old antenna.  At least the bottom section.


Fortunately, DXE sells replacement parts "...allow you to keep your Hustler vertical performing at its peak. Whether for maintenance or repair due to unfortunate damage, Hustler offers the replacement antenna parts that you need."  So I bought and replaced the lower mast section (P/N 4087-11) I think with shipping it was twice the cost i paid for the original used antenna but she is standing tall now:

 



The base of the antenna was in pretty good shape considering that it was basically in this desert environment for 11+ years.  When I decided to fix the bent antenna I dismantled the entire antenna and took it back to the Radio Ranch repair labs.  In the process I had to cut the radials to remove it as the bolts were badly rusted. 

ANTENNA RADIALS

The new installation would not  be able to attach the radials ( 2 per band) to the original tie points as they were slightly too short now. There would be no way to pull the radials back to make up for this with out digging them up - not an option with out a Nephew in site. ( he is now all grown up with two kids of his own to dig holes with)  Instead, I fabricated a radial plate out of 4 Stanley angle mending brackets:

I simply formed a square ( 2 under, 2 over ) and fastened with #8 SS hardware. The bracket was bolted to antenna base with a salvaged TV antenna "U" bolt that happened to come complete with a mast clamp ( a second bracket that prevents crushing the square antenna tube:

But instead of preventing crushes, I drilled a couple of well-placed holes near the "top" edge of the clamp and used it as the bracket:

These were fastened with 1/2" and only one nut and lock washer as the space is tight between the mast clamp.  Finally the original radial tie points screws were replaced with stainless screws, washers and nuts. Replacing the original "stack of nuts" that corroded before.  I attached these points, in a bit of overkill, with two ground straps made up of a length of braid salvaged from an old RG-8 cable, they look pretty impressive anyway.


At the end of the day, the bracket is mostly buried in the sand anyway. The first 6" of the insulation of the original radials as you can see - is now long gone due to exposure to the elements, are now safely buried under sand and these small stones.   The connection point and UHF connector are now wrapped in tape and a large tube of heat shrink as well.

THE WORKS.

BTW we made some PSK contacts with 5 watts on 15 and 20 meters and a couple of RTTY and - of course -  CW.  The contacts ranged from Cuba in the east to Japan and Russia in the west.  All bands but 10 meters was tried but i think that band was not too active the day I tested it.

Other Toy and Good Guard Doggie

Stay Tuned!

 

~ ~ ~

DSP-610 ~ PA Build

Slow Power Amp.

I know this is on a slow track but progress is progress.



90% Complete Power Amp

 

 

It has been a while since I posted any progress on this build.  The main build took place, mostly on weekends between 9/1/2013  through 11/09/2013.  The board has a couple of interesting quirks...

TIP:  I used a Red Sharpie marker to mark uninstalled (DNI) components:



Note: C6 and C31 are Marked DNI Parts

TIP: Two soldering irons and a solder gun were also very useful in this build. Use two irons as heat sources  for removing mistakes (caps and resistors) to heat both pads at the same time.  I used the 100W gun to solder to the substantial ground plane.

RF Connection Mods.

First, the antenna jacks and RF layout is a bit difficult to figure out.  I put shorting jumpers on the path to allow one antenna for TX and RX.  This seemed the most straight forward for operations.

 

RF In Connector

Then I had issues with the 0.1" headers for RF connections.  I used an Xacto knife to scrape a couple pads for mounting the jack.  I tinned the pads and flowed a generous fillet of solder to the connector




RF In End-Launch SMA connector...

 

Antenna Connector

The antenna output is a vertical launch SMA.  I could not find a suitable connector. While an end launch location would have been more convenient, but I could not figure out an RF friendly placement.  There is a trace on the left-hand side of the board near the RF coils. 

Instead, I modified  a SMA connector by cutting off the mounting tabs. I then used a file to machine them flush (brass works easily) and used the existing antenna pad for the center pin.  The ground connection was made by scraping the blue solder mask, tinning the copper exposed, and "sweating" a fillet with a generous amount of solder. The ground connection is probably adequate.

The modified SMA connector is seen mounted in this picture.  It is pretty substantial and there is enough room for the connector, which will be a right-angle SMA plug:

New RF Connector near the White AXICOM Relay

If I would have planned ahead a little better, I would have done this before mounting the Relays and potentiometers.  I did not want to remove or melt them by trying to solder the left-hand side, and had to be extra careful not to melt the plastic on the pot. 

The Transformers and Coils...

Winding school. 

Count the turns on the inside of the toroid cores. Scrape and tin the wires.  The instructions are from the Soft Rock 50, plans you need to translate the part designators between the two different boards.

Coils (L7, L8, L9, L10 & L11)

The five  toroid coils were pretty straight forward, 3 with 7 turns of AWG #22 and 2 with 5 turns on T-50-6 (Yellow) cores.  The red enamel stained the cores a little when tinning the wire. NOTE:  L7 is a little tricky to mount, be careful there is a large ground via close to the pads, don't solder to that hole! Here are the winding specs. from the BOM;

L7,L8,L9 T50-6 CORE 7 TURNS #22 ENAMELED WIRE (6") AMIDON T50-6

L10,L11 T50-6 CORE 5 TURNS #22 ENAMELED WIRE (5")

The DSP610 PA Coil - Family Portrait

BP Filters

I did a manual sweep of the two filters.  I am not too happy about the 10 meter filter.  I need to check the values of the caps etc. It seems shifted to favor  12 Meters..

 

12M - 10M Filter Response

The plot of the 50 Meter pass filter looks pretty reasonable. Very much as expected.

6M Filter Response

 

 

Transformers (T1) and (T2)

 

These two were just as described:

"...[T1] on the PA board two loops of #18 wire through a BN43-202 Core. The wires are cut to 3" (75mm) each and stripped so that the insulation is 1 5/8" (65mm) long.'

 (Seen on right side with Red and White #18 wire);

"...[T2] 3" (75mm) length of RG-316, remove the outer jacket from one end and expose 0.75" (20mm) of the shield... Remove the outer jacked from the other end of the wire so that the insulation length is 1.5" (40mm)....Loop the wire through the BN43-202 core, unbraid  the remaining shield wires making sure that the shield on both ends of the wire point in the same direction. Strip the dielectric from the two center conductors. Tin and trim both shields and center conductors."

Seen on left side of the following picture. (basically, just a short length of RG-316 coax thru binocular core):
 

 

T1, T2 and L7 (Note via near L7)

Transformer (T3)

The mounting pad for T3 was not good. I applied a little too much heat and the pad lifted;

 After close examination it appeared that there was no electrical connection to the pad so I attached the rather substantial transformer to the board with a dab of 2 part  epoxy.

Transformer (T4)

The instructions are pretty clear for this transformer:

"Step 1:  Wind 2 windings each using 18" of #30 Kynar wire, (Green) 10 turns, one winding through each hole in a BN43-202 core,  ( I wound in same direction)..

Step 2: Cut 2 pieces of #22 Teflon wire, (I used Red and White) Strip the ends so that the insulation remaining is 7/8” long, the length of the bare wires is not important just so it’s long enough to go through the PCB. Tin the ends:"

T4 on DSP-610 PA

I did not really follow the mounting instructions, I just pulled the wires thru marked and stripped the lengths to match,  For the #22 wires I just measured the insulation and simply bent them to feed the leads thru the circuit board pads.

Transformer (L6) 

The description for L6 was pretty vague... (T1 = L6)

"..[L6] has 2 windings on a FT37-43 toroid: the primary consists of 2 turns of #26 enameled wire, stripped and tinned; the secondary is 13T of #26 enameled wire. It's best to wind the secondary first then wind the primary over the secondary. Try to form the leads to match the pads in the PCB..."

This was the most confusing part on the board  for me.  First a transformer labeled as an inductor? Anyway...The winding instructions are pretty straight forward but not a picture to back up the description.  Here is what I came up with...

 

L6 as Wound

The best way I see is to run "two" turns is to loop it (green wire) so it passes through the torrid twice with the most wire through the toroid, exiting on the mounting side. Forming the leads is also a little tricky. To make it match the schematic, after some careful study of the PCB I ended up with this:

 

L6 with leads Formed

 

The First Part Was...

 

Oh, yeah. the first soldered part on the KD6VKF DSP-610 project was L1 on 9/1/13:

 

 

L1 Installed

The next installments; Transistors, DC Bias adjustments, and compete the testing the board. Please Stay tuned!  (The KD6VKF DSP610 will eventually get done, really ☺)

~ ~ ~

DSP-610 ~ Fabricating the PA Heat Sink

Sinking In..

 Poking around in the local surplus store last weekend, I found this roughly 4" x 6" 16-fin heat sink in a bin called "scrap aluminum"!

With out even measuring the part I put down the $2 and brought it back to the ranch,  As you can see a near perfect fit!  I am not sure this will provide adequate cooling or even how I plan to mount it in the chassis but it is a start to the power amp build for the DSP-610

 

 

 

For Good Measure

It would be too much to ask that any holes on this part would be usable.. and this was the case.  I think this was from a power supply or battery charger of some sort...probably a military device. I used the DSP external PA PCB to mark the locations of the required holes.  The trick was to find free of holes, or not too close anyway.

 

After studying the data sheet it looks as if the pin outs for the board intended the TO-220  transistors, to be mounted under the board.  Which works out that the heat sink (or chassis) will work under the circuit board.



 

This also explains the over sized holes...  The screws holes were drilled an tapped to accept #4-40 hardware.  Access through the holes will allow easy mounting to the sink. 

 

 

 

 

These spacers were only for test fit, the final hardware was #4-40 1/4" hex M-F standoffs, which will reduce the lead length,  The bends for the leads may be  a little tricky as I did not get the mounting holes exactly centered...but it should work out OK.

 



 

A dab of heat sink compound on each, and I think this will work!

 

 

READY TO BUILD...

The board seems to have found a good home!  I hope the mounting in the chassis will be OK and this assembly will dissipate the required heat for the RF  power transistors.

 

 

 

DSP-610 Tranceiver - Do We Need a Bigger Boat?

 We sometimes like to get surprises here on the old radio ranch but then again sometimes...



Ahhhh...?

 

The order from Newark Element 14 came this week.  It was neatly packed and arrived intact but when I got the question form the radio wife as I arrived home from work; "What the hell exactly are you building back there?!"  she pointed to this giant sized box that arrived earlier that day, she is used to getting the small envelopes of parts but this was definitely out of the norm. I thought there may be some trouble with the latest order.  I knew there were 70 line items in the order but these are supposed to be SMALL parts!

 

New DSP610 Project's Parts~ the project's bin on top



 

I had visions of 70 reels of parts contained inside. This kind of mix up has happened before. Once, we ordered 24 ea.   Fahnestock Clips  What came from Mouser was 24ea. boxes of 100 Fahnestock clips! Yes,we had to return 2376 clips. At least they arranged the pickup!

 

 

But it turned out that the packaging was simply overkill.  I smiled as I unpacked the box as it brought back an ancient memory...I suddenly remembered the first Microprocessor I ever ordered way back in the dark ages of computer epoch, the days we had to build our own.  I had wrote a letter and enclosed a check which I sent sent to RCA Corp. for an order for 1 ea. RCA 1802  Microprocessor and weeks later when it arrived at my parents house ( I was still in HS, and yes,  the chip was brand new at the time so you do the math  :)  as a overkill plus-sized crate of a shipping box, with one chip buried in a ton of packaging. I think my my mom had a similar reaction.  I always thought that the guy who shipped that to my young self had a strange sense of humor, or at least I hoped I got the joke.

 



 

...Or Not!

 

So now, all is well once again, on the Ranch of Radios.  The parts once removed from their copious packages fit neatly in the project bin.  Although the scale of this radio is probably the biggest, at least from the sheer number of components involved, we have ever attempted in the RR.  It took nearly an hour to order these not to mention about another hour to inventory this one shipment!  I can only imagine the time the designer Jim Veatch devoted to this.  It is incredible he completed this whole effort single handed!?!  Way to go Jim!

 

Next, I will upgrade the soldering station and magnifying equipment in the lab to start putting this beast together..

 

 

  

 

~STAY TUNED!~