All I want for Christmas is... an HT-37 L25 Choke-- 9 Henries at 135 ma

Following my own advice to prepare for Straight Key Night, I tried to fire up my venerable Hallicrafters HT-37 transmitter. It didn't work.  I quickly determined that none of the oscillators were working, so my troubleshooting focused on the power supply.  Sure enough, the choke in the low voltage power supply is open.  That's bad.  

I briefly considered giving up on this old rig.  I don't really like working with tubes anymore.  And this thing is very heavy -- a real beast.  DX-100-like in its heaviness.  It can be hazardous to your health just moving this thing around.  Opening up the case is not easy. And there are nasty voltages in there....  

But I  have had this transmitter since 1973 or 1974.  I have fixed it many times, in several countries.  I got it from a member of the Crystal Radio Club when I was a kid.   There are parts given to me by Pericles, HI8P in the Dominican Republic. I used it to transmit through Russian satellites.   That transmitter is like an old friend.  I just can't give up on it. 

So I need to replace or repair the choke.  Is there anyone out there who has a junker out in the garage or some other source of L25?   Or does anyone know of a business that could rewind the choke.  Please let me know.  I have decided to leave the rig on the bench until I get this thing fixed (it is too heavy to move multiple times!)   

It it Hallicrafters Part Number 056-300259. L25 -- 9 Henries at 135 ma.  Help! 

SolderSmoke Podcast #208

SolderSmoke Podcast #208 is available: 

http://soldersmoke.com/soldersmoke208.mp3

15 December 2018

Pete and the California fires
Bill goes to Brooklyn
2 meter simplex
A return of the trivial electric motor
Audio from Mars
HF Conditions -- a real mixed bag

Pete looks back at 2018 -- The Year of the SSB Transceiver -- Lessons Learned

Hans Summers, the QSX and the virtues of SDR
W7ZOI's DC Receiver Retrospective
The 1972 Solar Flare and the Vietnam War

SHAMELESS COMMERCE:  Buy your gifts through the Amazon link to the upper right. 
Consider SolderSmoke the book as a gift.  Visit Pasta Pete's for cooking ideas. 

Don't Build It!   Sage -- but unexpected -- advice from Pete. 

Straight Key Night approaches. 

Book Reviews:  
--"What is Real?"  (Quantum Physics)
-- RHdb by K6LHA.

Movies
"Bohemian Rhapsody" 
"First Man" (Not yet!)

MAILBAG: 
Steve G0FUW
Ed KC8SBV 

Free Book! RHdb -- The Radio Hobbyist's Designbook by K6LHA

http://hanssummers.com/k6lha-design-book.html

Another AMAZING Homebrew Vacuum Tube (Valve)

I feel a moral obligation to put these projects on the blog every time I see one.  It just seems like the right thing to do.  Great work on the Pilotron.   Great workshop video also.  

Built-in Spectrum Analyzer in Hans Summers' QSX Rig.

I agree completely with the e-mojis.   Wow!  Cool!  I love it! 

Hans Summers is a genius. 

This is almost enough to make me get with the program and embrace SDR.  

Hans has done what seemed to have been impossible: true homebrew with SDR. 

First Audio From Mars

How long will it be before NASA starts getting critical comments on the audio quality, along with very confident statements about how to change the audio settings on the menu?  Well, at least they have "presence."

The Elser Mathes Cup awaits a winner!   

A Beautiful Launch! Watch the Video

Today's SpaceX Falcon 9 launch of Farhan's Exseed Satellite was really spectacular. Congratulations Farhan!  Really inspirational stuff. 

Now we wait to hear the bird.   If I have loaded the orbital information correctly, I should have my first chance this evening.   I have my antenna positioned.  

DON'T BUILD IT! Sage Advice from Pete N6QW: Why You Should NOT Build an SSB Transceiver

Be sure to read the comments.  Especially my comment. And Pete's response. 

https://n6qw.blogspot.com/2018/11/2018-year-of-ssb-transceivers_27.html?showComment=1543673593869#c2528546290216719692

Launch Delay -- they will try again tomorrow

https://www.nasaspaceflight.com/2018/12/spacex-falcon-9-sso-multi-sat-launch/

Launch Day! Godspeed Exseed! 1:31 pm Eastern time. Video links here.

Farhan posted this message and the above video to Facebook today (I have the video cued up to around the 5 minute point): 

We are all set for the launch of ExseedSat... There are two tiny switches at the bottom of the satellite that keep the satellite switched off while it stays in it's container. Once the satellite is ejected, the switches are released and the satellite wakes up. 
There are 36 satellites on this launch, some belong to close friends in the satellite fraternity. We wait for all the satellites to drift out and after 45 minutes, the antennas are depolyed and we will start beeping signals home.
Here is a test of that process. You can skip to the fifth minute to watch the antenna depoly .

I really like the tape measure antenna.  This recalls the earliest OSCAR satellites.  And let's not forget that OSCAR 1 also launched from Vandenberg.  So there a lot of good tradition flying with Farhan's bird. 

Press reports indicate a launch time of 1:31 pm Eastern time today.   I think you can watch it live through the video window below.  Or try this link: 

https://www.youtube.com/watch?v=Wq8kS6UoOrQ 

Cubesat Launch Now Scheduled for Sunday Morning (California time)

Here is an update from the San Luis Obispo News: 

https://www.sanluisobispo.com/news/local/article222438135.html

It kind of makes you wish you were out there... 

https://spacenews.com/dedicated-rideshare-falcon-9-launch-raises-satellite-tracking-concerns/

https://www.theverge.com/2018/12/1/18114894/spacex-falcon-9-reusability-sso-a-mission-rideshare-satellites

Totally Absurd -- Farhan Being Questioned in a Police Station

I walked into the shack this morning hoping to read good news about the InSight landing and the impending launch of Farhan's satellite, but instead I found this message from Farhan in a police station.   This is really absurd and disheartening.   Someone (not Farhan!) altered the Indian flag and put it into an image of Farhan's CubeSat.  So with 24 hours to go before the launch, our friend Farhan finds himself in a police station. 

Stay strong Farhan!  You have a lot of support around the world.  

Bad Weather Postpones Falcon 9 Rocket Launch

March 30 2018 Falcon 9 Launch from Vandenberg AFB

https://lompocrecord.com/news/local/spacex-launch-from-vandenberg-air-force-base-postponed-again-this/article_6a46fade-20fd-5e3b-8546-409f3d25cb47.html

Falcon 9 Cubesat Launch Now Set for Wednesday

It looks like the Falcon 9 with Farhan's CubeSat is not scheduled to launch this Wednesday between 1030 and 1100 West Coast time.  Above you can see a similar launch.  

https://www.sanluisobispo.com/news/local/article222135690.html

Where in Space is Elon Musk's Tesla Roadster? -- Interactive Animation

Fun stuff from Heavens Above.  What a great web site! 

https://www.heavens-above.com/Tesla.aspx

The Max Valier Satellite Flies Over, Sending CW

I understand the launch of Farhan's CubeSat has been delayed a few days.  That's the way it works in the rocket launch biz --patience is required.  In the meantime, I've been practicing with my receive system.  Today at 1000 local the Max Valier satellite flew to my west.  It rose 78 degrees above my horizon to the W NW.  I left my three element quad pointed in that direction and waited for the satellite (which had been launched from India) to fly through its pattern.  

The CW beacon was quite strong, very visible and audible through my RTL-SDR dongle and HD-SDR software.  You can see it and hear it in the video above.  There is something quite charming about this very personal Morse message coming down from orbit and then passing through all that digital technology.   

More info on the satellite: 

"Max Valier Sat" is an amateur satellite built in cooperation by:

• "Max Valier" High School in Bolzano/Bozen (Italy)
• OHB System AG from Bremen (Germany)
• Max Planck Institute for Extraterrestrial Physics from Garching (Germany)

Its main payload is an X-Ray telescope devised and made by MPE. Data generated by this detector will be transmitted, together with housekeeping data, over an amateur radio link with frequency 145.860 MHz.

A second payload is an amateur radio beacon transmitting a message in Continuous Wave. The beacon's frequency is 145.960 MHz

"Max Valier Satellite" was launched by the Indian Rocket PSLV-C38 on June 23, 2017 at 9:29 am IST (05:59 am CET) from Satish Dhawan Space Centre.

More tech details: 

http://spaceflight101.com/pslv-c38/max-valier-sat/

https://www.ohb-system.de/press-releases-details/max-valier-nano-satellite-successfully-launched.html

Regarding the CW beacon: 

Beacon by Holger Eckardt DF2FQ:

• Transmit frequency is 145,960 MHz (IARU and ITU coordinated).
• Modulation is CW:
• Duration of one dot is 114 ms.
• Duration of one dash is 342 ms.
• Interval between words is 1881 ms.
• Interval between repetitions of the message is 6000 ms.
• The beacon transmits Max Valier Sat's call sign and a greeting message.
• Transmitting power is 500 mW.

And who was Max Valier?  Quite an interesting fellow: 

https://en.wikipedia.org/wiki/Max_Valier

Max Valier in his Rocket Car in 1930

From BITX to SpaceX: Falcon 9 To Launch Farhan's Cubesat on Monday (video)

1. https://www.rocketlaunch.live/launch/spaceflight-sso-a-su
   
   will carry a live feed of the launch
2. 
   
   SpaceX will live-stream the launch as well on their YouTube stream. Also - this will be the first SpaceX booster to fly three times, and the first to launch from all three SpaceX pads.
   
   https://forum.nasaspaceflight.com/index.php?topic=46756.0
   
3. https://www.deccanherald.com/state/india-s-first-home-grown-703343.html

Special thanks to Dave Bamford for the BITX to SpaceX line! 

Launch Date Approaches for Farhan's Satellite

It looks like the launch date might have been moved up from 24 November to 19 November. 

W7ZOI: Direct Conversion Receivers -- Some Amateur Radio History

http://w7zoi.net/dcrx68.pdf

Farhan and Pete WB9FLW alerted me to this wonderful article by Wes Hayward, W7ZOI.  I guess my interest in DC receivers must have been noticed by the Google algorithm because I am bombarded by ads extolling the virtues of "Zero IF."   Hey Google -- I'm already a believer!  I was converted by W7ZOI's 1968 article in QST. And my belief in the technique has been greatly reinforced by his November 2018 50th anniversary article. 

There is so much good stuff in Wes's look-back piece.  The travails of trying to write for QST are presented very well.   And we learn that none-other-than Doug DeMaw himself is responsible for the use of the word "presence" in describing amateur radio audio.  

This article has inspired me to take a new look at the DC receiver I built last winter.  Mine needs some work. I think it is kind of deaf.   It could probably benefit from a diode ring  detector.   But it already has presence.   

http://w7zoi.net/dcrx68.pdf

Thanks Wes.  And thanks to Farhan and Pete for the heads up. 

1972 Solar Flare Caused Naval Mines to Explode

There are reports out this morning that a big solar flare in 1972 caused naval mines placed by the U.S. off the coast of Vietnam to explode.  

https://www.livescience.com/64062-mines-solar-storm-1972-vietnam.html

https://www.colorado.edu/today/2018/11/12/1972-solar-storm-triggered-vietnam-war-mystery

Background info: 

https://oraprdnt.uqtr.uquebec.ca/pls/public/docs/GSC418/F1929448428_Solar_Superstorm__Astronomy_Sept_2008.pdf

I remember this solar event.  It caused aurora near New York City: 

https://soldersmoke.blogspot.com/2009/09/carrington-flares-aurora-where-were-you.html