LHS Episode #389: Jailbird Jamboree

25 January 2021 | by Russ K5TUX  |  Leave a Comment (1)

Welcome to Episode 389 of Linux in the Ham Shack. In this episode, the hosts discuss illegal activity on the air, the purpose of amateur radio, a remote head unit for the Icom IC-7100, Linux on the Apple M1 chip, a new frontier for Red Hat Enterprise Linux, ethical open-source licenses and much more. Thank you for tuning in and have a great week!

73 de The LHS Crew


Russ Woodman, K5TUX, co-hosts the Linux in the Ham Shack podcast which is available for download in both MP3 and OGG audio format. Contact him at [email protected].

AN/GRC-9 aka “Angry Nine”

24 January 2021 | by Richard AA4OO  |  Leave a Comment (11)

 AN/GRC-9 - Long lived military comms

My lovely (and radioactive) RT/77-GRC/9


I don't recall where I first read about the Angry Nine, but it captured my imagination.  I read everything I could find about them and decided it would be great fun to operate such an antique on the ham bands.   There is no logical reason to desire such a QRP radio.  The low power output on CW is indeed, 5 watts and high power is a pileup busting 15 watts.   The AM transmission are 1 watt and 7 watts respectively.  That's almost QRPp for AM mode.

I'd had some experience restoring old tube equipment; my Heathkit HW-101, Knightkits VFO and Hallicrafters keyer, and I figured I'd take the next plunge and learn to use a receiver-transmitter combination and see how mobile high-voltage power worked from Vibrators and Dynamotors.   

These radios seemed to have been more plentiful in the surplus market 10 - 20 years ago.  Now you'll occasionally see one come up on eBay or other sites, but often times they are in very rough shape or the they are foreign language versions.  I bid on a few auctions over the past couple of years and the bidding always exceeded my threshold for what I thought it was worth.  The one above was part of an auction from an individual who had actually trained on these units prior to deploying to Vietnam.  Later in life he became interested in finding one and spent time in military surplus warehouses going through pallets of equipment to find one in good shape.  This particular unit is made up of a Lewt manufactured transmitter and a Telefunken receiver.  The original owner preferred the receiver characteristics of the Telefunken over the Lewt manufactured model, so he paired the two.

Many of these old units are radioactive, due to the radium paint used on the front panels to make the lettering glow in the dark.  This particular unit is off the lower scale on the Geiger counter and must be handled with care.  Basically, I have to be careful to not touch my face with my hands after operating the unit and wash my hands thoroughly.  Radium emits Alpha particles, which are not especially strong but the resultant radioactive dust from the front panel shouldn't be breathed or ingested.

Hot receiver, in more ways than one


The AN/GRC-9 is a set of components primarily comprised of the RT-77/GRC-9 receiver-transmitter, capable of operating between 2-12 MHz in CW, MCW and AM modes.  MCW is a modulated form of CW that can be received by radios that do not have a BFO (i.e. a normal AM receiver).  

It is a mid to late 1940's design and was first documented field use in the Korean War, and was in active use through the Vietnam War and continued to be maintained in US military warehouses until 1974.  It was in use by other nations long after, most notably the Dutch military.

Out of the case, tracing a low B+ power problem

Close up of the bottom of the receiver board


Transmitter




Power on the move

Designed to be used in the field, both vehicle mounted and carried by mobile infantry; there were a number of ways to supply power to the unit.  There were a few different Vibrator/Dynamotor units, that could operate from common DC voltages of the time (6v, 12v, 24v) as well as a hand cranked, field portable generator.

Keep in mind that the state of the art at the time of its design used vacuum tube technology and in the case of the RT/77-GRC/9 it required the following voltages:
  • Transmitter Plates -- 475 - 580 v @  100ma
  • Transmitter Filaments -- 6.5 - 6.6 v@ 2 amps
  • Receiver Plates -- 105 - 120 v @ 45ma
  • Receiver  Filaments -- 1.35 - 1.5 v @ 500ma
  • Keying Relay -- 6.0 - 6.9 v @ 575ma

That's a tall order for mobile and portable power supplies but designers in the 1940's were quite clever in packing power supply units.   I managed to obtain both the hand cranked GN-58 generator with the base chassis and seat for portable operations, and a DY-88 for fixed / mobile operations.  


DY-88 mobile power supply

DY-88 set to 12v powered by Amateur 12v supply

Vibrator power supply for low B+

Power filtering

I supply the DY-88 from either an RV battery or an amateur 12v power supply.  When in Standby the DY-88 draws less than 1 amp, but placing the radio in Send mode switches on the Dynamotor which draws 12 amps @12v, without key-down and up to 14 amps on high-output key-down.  It will drain an RV battery pretty quickly at that rate if the radio is left in Send mode, and works an amateur power supply pretty hard as well.  So don't expect to operate remote off a battery alone for too long if your having lengthy QSOs.  An added benefit of the DY-88 is that when the enclosed Dynamotor is running you'll have a nice extra 85 dB of generator noise to accompany your listening pleasure.


GN-58 portable field hand-cranked power supply

Generator head in carry bag

NOS Shiny




Deployed


The GN-58 is a tough workout since it has to be cranked by hand at 60 rpm continuously.  Obviously, you need a partner unless you can figure out how to crank it with your feet while sending CW. You will also want that partner to help you carry the GN-58, and the accompanying accessory bag for the chassis and seat.  IT'S HEAVY.  I haven't weighed everything, but according to the manual that came with the set, the radio / generator / accessories including antennas comes out around 120 lbs.  

If you have a BC-48 battery hooked up then your human power supply can pause cranking while your receiving.  I have a BC-48 battery enclosure that has been gutted of the original, long-dead material and replaced with 10x 9v batteries in series for the low B+ and two D-Cell batteries in parallel for the receiver filament supply.


Accessories

Bag of goodies

The radio itself has a carry bag, as well as a bag for the GN-58 legs and seat, the vertical antenna, and miscellaneous.

There's another bag (shown above) for carrying power supply cables, keys, hand mic, long wire and doublet antennas, external speaker, torture device headphones, torture device in-ear phones, as well as a box of spare tubes for the radio.

If you're traveling in a squad sized group, then many hands make light work, otherwise you're going to be making a lot of trips hauling your QRP rig up the hill.

Headphones

These Western Electric headphones clamp tightly over your ears sealing out QRM and squeezing your head like a vice.  After 10 minutes I was confessing to sins I'd never committed. 








In order to use the headphones the RT/77 receiver must be removed from the case and an impedance switch on the back, changed from 4000 to 250 using a screwdriver.  The ham I bought my set from had constructed a CW audio filter along with an impedance switch on an outboard box, that allowed the use of the headphones without switching the impedance on the receiver unit.

Homebuilt CW filter with impedance switch

Speaker


The external speaker is a rugged, high impedance device (4k Ohms), that after all these years can still output audio at high volumes without distortion.  It has a built in thumbscrew clamp that allows it to be attached to vertical or horizontal objects.

Alternately, the thumbscrew can be used in combination with the vice-like headphones to extract information from a prisoner.

Antennas

The AN/GRC-9 comes with 3 antenna systems; a multiple section, whip vertical for quick field setup and mobile use, a long wire that can be quickly deployed in a fixed station as a sloper, and a doublet for best reception, transmission in a fixed location.



For testing purposes I have my radio hooked up to my 80m Windom, which it tunes very nicely on 80m, 60m, 40m and 10m bands. 

When the weather warms a bit I will be taking the radio out for some portable use and I'll try it out with the antennas that are part of the AN/GRC-9 set.

Spares

As a military radio, it was expected that repairs should be performed in the field when possible.  The radio shipped with spare tubes for the receiver-transmitter, as well as spare tubes and vibrators for the DY-88 power supply.


More to come

In the few days I've had the AN/GRC-9 the only problems I've encountered have been related to the old DY-88 power supply.  Old vibrators cans are generally seized up, as was the case with mine.  Eventually mine became un-stuck after repeated applications of power but there are some methods to restore truly frozen ones using AC current and light bulbs (see Notes section below).

I've made about half a dozen contacts on the ham bands, including a 40m contact to a station in TX which is kinda DX for my locale.  I've received nice signal reports.  I've specifically asked stations about my "chirp" during QSOs and they've reported it as "not bad" and "charming".  When operating from the VFO (master oscillator) rather than a crystal, the GRC-9 will "chirp". It was considered an acceptable design trade-off at the time.  I've listened to the transmitter from a remote WebSDR station to hear the chirp for myself, and I agree that it isn't extreme and lends some character to the station.  The unit does drift about 200 Hz during a QSO which I also think is quite acceptable for it's age.  It's possible that if I spent more time in Send mode prior to a QSO to allow the transmitter tubes to warm up the drift might be lessened, but keeping the radio in Send mode puts quite a load on the power supply (both the 12v supplying the DY-88 and the human cranking the GN-58).

The RT-77 Telefunken receiver doesn't offer much in terms of selectivity and on a crowded band there's a lot of stations to contend with in the passband.  The outboard CW filter deals with this nicely, but it is so narrow that when shifting from Send to Standby, the resulting frequency shift often throws the station I'm receiving out of the filter's passband, so that's a bit tricky.

The receiver's tuning knob also is very coarse, in that fine adjustments are made by breathing on the knob.  However it has zero backlash, which is amazing in a piece of equipment this old.  The markings on the receiver are in 50 kHz intervals so the only way to really figure out where you are is to look at RBN for your spot.

50 kHz spacing when reading the frequency on the receiver
Note the 7.2 is 7.200 MHz in the 40m band


Images

Enjoy the pictures of the AN/GRC-9























Notes

Instructions for restoring a vibrator to operation

VB-1 and VB-7 are interchangable. I think I recall reading somewhere that VB-7 is a "lightweight" version of VB-1 but I won't swear to that.

The base is 4-pin, and the pin numbers are counted as on a vacuum tube with the same base. I wish I could post an image here without uploading it somewhere but if it's possible I've not figured out how to do it. The pins count clockwise from 1 to 4 looking at the bottom of the vibrator or the wiring side of the socket. The two large pins are 4 and 1 and the two small ones are 2 and 3.

There are two basic types of vibrators, called Series and Shunt. The Series type has a contact in series with the coil. VB-1, 7 and 16 are all Series types. I'll skip the Shunt type for now.

Pin 1 is common. Pin 4 is coil. Pin 2 is the NO (Normally Open) switching contact and Pin 3 is NC (Normally Closed). To test a VB-1/7, use an ohmmeter to check continuity from 1 to 4. If the reading is infinity, the coil could be open but this seldom happens. The problem is probably the vibrator contact. If the reading is a few ohms, connect +6 VDC to Pin 4 and -6 VDC to Pin 1. The vibrator should run. If it doesn't, most likely the contact is welded. About the only solution is to open up the vibrator, unstick the contact and try to burnish the burn marks out of the contact.

If the vibrator does run, go to the end of this screed and do the final test.

If the reading is infinity, here's how to use the two or three lamps to (usually) fix the vibrator. SAFETY NOTE: bear in mind you are dealing with either 120 or 220 VAC. If you jury rig the hookup, do all of your connections and disconnections with the "rig" not connected to the AC line. In other words, don't touch anything except the plug on the line cord or (if you go to that much trouble) the ON-OFF switch when the line cord is plugged in.

Connect the hot side of the AC line cord to one side of both lamps. Connect the ground side of the AC line cord to Pin 1 of the vibrator (or socket if you use one). Connect the other side of one of the lamps to Pin 4 and the other lamp to Pins 3 and 2. If you splurge and use three lamps, connect the "cold" side of the second and third lamps to Pins 2 and 3 respectively.

Check all the wiring and when satisfied all is OK, plug in the line cord. Probably nothing will happen immediately. Within a few minutes to a few hours lamp 1 should begin flickering and you should hear the vibrator hum. Run the test until the second lamp begins to flicker or until both the 2nd and 3rd lamps flicker.

If you are only using two lamps, when the 2nd lamp begins to flicker, wait 1 or 2 minutes then remove power (unplug the line cord). Connect the 2nd lamp only to Pin 2 and plug in the line cord. If the 2nd lamp flickers, remove power, move the 2nd lamp connection to Pin 3 and apply power. In either case (with the 2nd lamp now connected to pin 2 or 3 only), let the test run until the 2nd lamp again flickers.

For a final test, connect one lamp to Pin 2 and one to Pin 3. Connect 6 VDC to Pins 4 and 1. With the vibrator vibrating apply power to the two lamps. They should flicker alternately. Note that for this test, either use a 6 volt battery or a 6 VDC supply with both outputs not grounded. I wouldn't try to use the battery in the Jeep just in case you mis-identify which side of the line cord is grounded and which is hot.

Although a vibrator that is going to be fixed by this procedure will usually begin to work after say no more than half an hour, I have seen it take several hours. So if I have one that didn't start working fairly quickly, I'll let the test run up to about 8 hours max (or overnight) before giving up.

Robert
Gunner
USN Retired
MVPA 9480

Richard Carpenter, AA4OO, is a regular contributor to AmateurRadio.com and writes from North Carolina, USA. Contact him at [email protected].

Snow stopped Transmission.

24 January 2021 | by Steve G1KQH  |  Leave a Comment (4)

 This Sunday morning we have had a good dumping of snow over the Midlands area..

 

 

Around 12:00 GMT as I write this, my VHF/UHF array of antennas strapped to the side of the house are well plastered with the white stuff.  

Outside Temperature is Zero Centigrade.


Steve, G1KQH, is a regular contributor to AmateurRadio.com and writes from England. Contact him at [email protected].

I’m back

24 January 2021 | by Mike VE9KK  |  Leave a Comment (4)

 It has been 15 days since my last post but my last post was about our cat Oliver and our best buddy who we said goodbye to.  Some may think it strange but we have his ashes back home now in a cat urn.  It's only his ashes but to Julie and me, Oliver is back home now. 

It's now time to round the corner and get back to ham radio blogging. In my last radio post, I had just finished rebuilding my PC  and it's working great. What I mean by great is, it's fast, startup happens almost right away and all the radio programs work great. The other big event computer-wise was I finally upgraded from Win7 to Win10. In the past, I have posted about my going back and forth regarding upgrading to Win10. My first upgrade was a free upgrade that Microsoft offered if you were operating Win7. I did that (installed Win10 over top of Win7) and it was a disaster I was having sound device issues, some of my radio programs intermittently were giving me issues and some of my Windows startups had error messages and failed to start. I was told some or if not all my issues were related to me installing Win10 overtop of Win7 but at that point in time, I was not willing to wipe my drive clean and install Win10 and all my programs.

After my complete PC upgrade, I purchased Win10 and did a clean install on my new solid-state hard drive. I am happy to say that I have had no issues.  I did some research regarding Windows 10 and how on its own it installs updates at startup. I had seen many a post on radio sites how one day Win10 OS was without issue and the next startup there was issues.  Many times it was due to the fact that an update was the issue that created a problem! I was reading that a very recent Windows update if you had a solid-state hard drive and ran Windows defrag program it would not defrag your drive but erase the drive! As a side note, one should not defrag a solid-state drive in the first place. But there were many upset Windows users who had solid-state hard drives that were wiped clean!

Back to Windows 10 updating issue, I solved that by downloading a program that turns off Windows automatic update.  You can also turn Windows update off for 7 days at a time from within the Windows update program itself but you have to remember to reset it after 7 days or you will be updated. There are a few free programs out there that will stop Windows from updating The one I use is called Windows update blocker but there are others.... WUB, Windows update manager or WuMgr and Winupdatestop. The Windows update blocker program I use works great. 

I do believe it is important to update Windows as it is very important and keeps Windows running smooth and secure. Now you ask I feel windows updates are important but I have an update blocker installed on my PC? Let me explain the method to my madness, each month on the second Tuesday Microsoft sends out their update to our PC's. These updates at first do have issues and over the course of a few weeks Microsoft learns of them and sends out fixes.  I don't want to be a guinea pig for Microsofts updates and the best way for me to deal with this is to update after most if not all issues have been dealt with. I don't have a Microsoft crystal ball to know when to update but I do belong to a group that provides its members with a safe time to allow your OS to update. 

I have mentioned this group in a past post, the group is called Ask Woody and for a donation, it provides valuable information, posts and user groups for Windows users.  The group informs its users of safe update times to update as well as they will sectionalize the updates informing users of a certain update at this time should be avoided.  I do know about Mac and Linux OS's but I have tried both and for the radio programs I want run these OS's just don't cut it for me. 

Well, it's time for me to say 73 and thanks for stopping by the blog.....see you soon with a new post. 



Mike Weir, VE9KK, is a regular contributor to AmateurRadio.com and writes from New Brunswick, Canada. Contact him at [email protected].

LHS Episode #388: The Weekender LXIV

22 January 2021 | by Russ K5TUX  |  Leave a Comment (0)

It's time once again for The Weekender. This is our bi-weekly departure into the world of amateur radio contests, open source conventions, special events, listener challenges, hedonism and just plain fun. Thanks for listening and, if you happen to get a chance, feel free to call us or e-mail and send us some feedback. Tell us how we're doing. We'd love to hear from you.

73 de The LHS Crew


Russ Woodman, K5TUX, co-hosts the Linux in the Ham Shack podcast which is available for download in both MP3 and OGG audio format. Contact him at [email protected].

Hunting For NDBs In CLE 264

20 January 2021 | by Steve VE7SL  |  Leave a Comment (1)
 
YEK - 329 (courtesy ve3gop.com)

 
 
 
It's CLE time! 'CLE's are 'Co-ordinated  Listening Events, and NDB DXers around the  world focus their listening time on one small slice of  the NDB spectrum.
 
This time the hunting ground is 320.0 - 334.9 kHz.

Propagation on MF has been excellent this past week and hopefully will continue to be good.

A 'challenge target' for listeners in North America is YEK - 329kHz in Arviat, NU, on the NW shore of Hudson Bay. It's widely heard throughout North America and is a good target for listeners on both coasts. Listen for YEK's upper sideband on 329.424 kHz with your receiver in the CW mode.

When tuning for NDBs, put your receiver in the CW mode and listen for the NDB's CW identifier, repeated every few seconds. Listen for U.S. NDB identifiers approximately 1 kHz higher or lower than the published transmitted frequency since these beacons are modulated with a 1020 Hz tone approximately.

For example, 'AA' near Fargo, ND, transmits on 365 kHz and its upper sideband CW identifier is tuned at 366.025 kHz while its lower sideband CW ident can be tuned at 363.946 kHz. Its USB tone is actually 1025 Hz while its LSB tone is 1054 Hz.

Often, one sideband will be much stronger than the other so if you don't hear the first one, try listening on the other sideband.

Canadian NDBs normally have an USB tone only, usually very close to 400 Hz. They also have a long dash (keydown) following the CW identifier.

All NDBs heard in North America will be listed in the RNA database (updated daily) while those heard in Europe may be found in the REU database. Beacons heard outside of these regions will be found in the RWW database. These databases have recently been re-vamped and are slicker than ever before!

From CLE coordinator Brian Keyte (G3SIA), comes the following CLE info:

Hello all,

Here are all the details for this weekend's co-ordinated listening event.
First time CLE logs too?  Yes, please!
Short logs are always as welcome as long ones.

     Days:     Friday 22 January - Monday 25 January
     Times:    Start and End at midday, your LOCAL time
     Range:    320.0 - 334.9 kHz

Please log the NDBs you can positively identify that are listed in the frequency range (no DGPS please), plus any UNIDs heard there too.

Send your CLE log to the List, if possible not in an attachment, with CLE264 and FINAL at the start of its title.
Please show on EVERY LINE of your log:

  # The date and UTC (the day changes at 00:00 UTC).
  # kHz - the beacon's nominal published frequency, if you know it.
  # The Call Ident.

Show those main items FIRST on each line, before any optional details such as the NDB's Location, Distance, Offsets, Cycle time, etc.
As always, make your log meaningful to everyone by including your listening location and details of the receiver, aerial(s), etc.
It would be OK to use one remote receiver, with the owner's permission if necessary, provided that ALL your loggings for the CLE are made using it.

Joachim or I will send the usual 'Any More Logs?' email at about 20:00 UTC on Tuesday so that you can check that your log has been found OK.
Do make sure that your log has arrived on the List at the very latest by
09:00 UTC on Wed. 27th January.
We hope to complete the combined results within a day or two.

You can find all CLE-related information from our CLE page ( http://www.ndblist.info/cle.htm ), including a link to the seek lists provided for this Event from the Rxx Database.

Good listening
    Brian & Joachim
---------------------------------------------------------------------
From: Brian Keyte G3SIA          ndbcle'at'gmail.com
Location: Surrey, SE England     (CLE co-ordinator)
---------------------------------------------------------------------
 

If you are interested in some remote listening - maybe due to local difficulties - you could use any one remote receiver for your loggings, stating its location and with the owner's permission if required.( e.g. see  kiwisdr.com ) A remote listener may NOT also use another receiver, local or remote, to make more loggings for the same CLE.

These listening events serve several purposes. They

• determine, worldwide, which beacons are actually in service and on-the-air so the newly-re-vamped Rxx online database can be kept up-to-date

• determine, worldwide, which beacons are out-of-service or have gone silent since the last CLE covering this range

• will indicate the state of propagation conditions at the various participant locations

• will give you an indication of how well your LF/MF receiving system is working

• give participants a fun yet challenging activity to keep their listening skills honed

Final details can be found at the NDB List website, and worldwide results, for every participant, will be posted there a few days after the event.


The NDB List Group is a great place to learn more about the 'Art of NDB DXing' or to meet other DXers in your region. There is a lot of good information available there and new members are always very welcome. As well, you can follow the results of other CLE participants from night to night as propagation is always an active topic of discussion.

You need not be an NDB List member to participate in the CLEs and all reports, no matter how small, are of much value to the organizers.

Remember - 'First-time' logs are always VERY welcome!

Reports may be sent to the NDB List Group or e-mailed to CLE co-ordinator, Brian Keyte (G3SIA), whose address appears above. If you are a member of the group, all final results will also be e-mailed and posted there.

Please ... give the CLE a try ... then let us know what NDB's can be heard from your location! Your report can then be added to the worldwide database to help keep it up-to-date.

Have fun and good hunting!

Steve McDonald, VE7SL, is a regular contributor to AmateurRadio.com and writes from British Columbia, Canada. Contact him at [email protected].

LHS Episode #387: Compiling Software Deep Dive

18 January 2021 | by Russ K5TUX  |  Leave a Comment (0)

Hello and welcome to the 387th episode of Linux in the Ham Shack. In this episode, the hosts discuss concepts related to building software from source code. Topics include proper build environments, packages to install for easy building of software, how to get source, commands for building software and much more. We hope you find this talk interesting and informative and we hope you come back for Episode 388.

73 de The LHS Crew


Russ Woodman, K5TUX, co-hosts the Linux in the Ham Shack podcast which is available for download in both MP3 and OGG audio format. Contact him at [email protected].
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