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MRHS NEWSLETTER No. 44
Dedicated to True Believers World Wide
> Headlines - MRHS Participation in International Marconi Day 2014
- Meggers: Theory of Operation & Construction
- A Day at the Transmitter Site, or "It's Always Something"
 > MRHS Participation in International Marconi Day 2014 > Both Transmit and Receive Sites Will Be at Historic Marconi Locations > Date: 26 April 2014 > And You're Invited!
Each year the Cornish Amateur Radio Club organizes International Marconi Day (IMD), an on-the-air event to celebrate the birthday of the Great Man, Guglielmo Marconi, born on 25th April 1874. The IMD event is not a contest: it is an opportunity for amateurs around the world to make point-to-point contact with historic Marconi sites using HF communications techniques similar to those used by Marconi, and to gain an attractive Award for achieving the requisite number of Marconi stations worked.
K6KPH, the amateur station of the Maritime Radio Historical Society, proudly participates in IMD as an Award Station since we transmit from the historic 1913 Marconi transmitting station in Bolinas, CA. But this year our participation will be different and special. This year both the transmit and receive sites will be at historic Marconi locations.
All the buildings of the original Marconi receive site in Marshall, CA remain intact. Many have been lovingly restored for use by the Marconi Conference Center including one of the two Marconi cottages used by the Station Manager and Chief Engineer.
Now comes Ms. Kathy Wippert, Marconi Conference Center manager, with a generous offer to let the MRHS set up our receive site in one of those Marconi cottages. We will install vintage receiving equipment and our house built remote control panels to allow us to key the transmitters in Bolinas. With both transmit and receive sites at historic Marconi locations we think we will be one of the most authentic Award Stations participating in IMD.
 | | Restored Marconi cottage, now known as McCargo Hall |
> Public Invited - Operators Needed
The public is invited to visit the receive site at the Marconi cottage. We will have exhibits set up and maybe even MRHS merchandise available for purchase. The location of the Marconi Conference Center is stunningly beautiful, worth a special drive in itself. Why not make a special day of it with a beautiful day on the coast and a visit to a historic radio site? See location information below.
Morse operators are needed for this event. Some True Believers have already raised their hands for the coveted position of IMD operator at K6KPH for this event. Care to don the MRHS earphones and green eyeshade? We'd love to have you. As a special enticement we will have some very nice vintage receivers in service. Plus you'll be commanding the original KPH transmitters in Bolinas! Please let us know you're coming by sending an email to [email protected] .
We've got to be honest here - the equipment we need to transport for events like this seems to get heavier every year. Can you help us set up for IMD 2014 on 25 April? More hands make light the work so you and your vehicle would be a great help. We plan to muster at the RCA receive site (17400 Sir Francis Drake Blvd, Inverness, CA) at 1000 on Friday 25 April. If you can help you'll get to join us on Friday evening for K6KPH operations at the start of IMD at 0000gmt. Drop a line to [email protected] if you'd like to be part of the elite setup crew!
Dual KSM/K6KPH operating positions for IMD 2013, Jack Martini (L), last KPH station manager and Ray Smith (R), who sent the last KPH message from Point Reyes/Bolinas, at their keys
> Technical Details
We will replicate the original Marconi operations as closely as we can. Marshall was the original receive site and Bolinas the original transmit site. We will set up our receive and control positions at the Marshall site. The transmitters at Bolinas will be remote controlled from Marshall, just as they were originally, using narrow shift AFSK "tone sets" just as KPH did.
Original Marconi KPH operators on duty at Marshall
> Event Details
KSM and K6KPH will be on the air from McCargo Hall at the Marconi Conference Center in Marshall, CA from 1000pdt to 1400pdt on Saturday 26 April. See site information below. We'll post signs at the site directing you to the location
K6KPH will guard its usual frequencies (3550.0, 7050.0, 14050.0, 18097.5, 21050.0) on a selected basis. The remote control console allows for the use of only a few transmitters at a time so frequencies will be selected from the above group according to prevailing conditions.
> KSM Operational
KSM will also be on the air, keyed at various times from the Bolinas transmitter site and from the Marshall receive site. Do you hold a commercial radiotelegraph license? Visit us to exercise the privileges of your license and have it endorsed for operation at KSM. We expect that SS RED OAK VICTORY/KYVM will be operational on MF so you might get the chance to work a ship on 500kc!
 | | Unrestored Marconi hotel, for station staff, at the Marshall receive site |
> Receive Site Location
The Marconi Conference Center is located at:
18500 State Highway One (also called Shoreline Highway)
Marshall, CA 94940
Click HERE to see the location in Google Maps
GPS and on line mapping programs like Google Maps will guide you to the site from your location.
See you there!
> Meggers: Theory of Operation & Construction
Steve Pazar of the H Set Team likes to get to the bottom of things. And he goes deeper than most. Take for example his analysis of the high voltage tester we all know as a megger. No big deal, right? Well, maybe there's more to them than meets the average eye, as Steve elucidates below:
 | | Typical hand crank megger |
Picked up a dead hand cranked megger yesterday to add to my collection of other styles. Had never really dug into one of these before, and as usual, have learned a bit more about equipment by actually having to fix it. Since all of use these things, thought this might be of interest. The following applies only to meggers that use a meter movement.
The meters inside meggers are similar to, but in ways quite different than the usual D'Arsonval type meter. They use two armature coils. One is a 'bias' coil, and the other the 'defection' coil (my terms). You'll notice in all meggers the needle is way past the left side of the scale when idle unlike standard meters. The 'bias' coil is connected across whatever DC power supply the megger uses (115vac, vibrator/battery, or hand crank generator) with a resistor in series. When power is applied to the megger this 'bias' coil brings the meter up to the 'infinity' mark on the scale. In fact this is one of two calibration points. The other is zero ohms with a short across the megger's terminals.
The 'deflection coil' is the one that is connected between the power source and the unknown resistance. The lower the resistance, the more current through this coil and the higher the meter reads. Standard stuff. However what this arrangement does is makes the meter somewhat independent of supply voltage! This type of meter is called a 'ratio' meter, where the reading is proportional to the *ratio* of currents in the bias and deflection
coils.
 | | Steve Pazar |
Mechanically there are some key differences. In a D'Arsonval movement the armature is made up of a single, more or less rectangular coil that rotates in the magnetic field of a permanent magnet. In a megger meter,the 'deflection' coil is the same but the 'bias' coil is only wound on half of the armature, and located perpendicular to deflection coil.To add to the complexity, a D'Arsonval movement has two pancake torsion springs. One in front, one in back and each providing a connection to the coil. The megger meter has 4 or 5 of these springs to allow for independent connections to both coils, as well as providing the mechanical torsion needed for the armature. Very complex and much larger than a standard meter.
Steve P
> A Day At the Transmitter Site, or "It's Always Something"
And speaking of antennas, we're in a difficult situation at the moment. Several antennas are on the ground and a tree has taken down several feed lines. This is a big deal that will require a large outlay for a crane and crew to repair. And we'll need every antenna we can get for Night of Nights 2014 coming up on 12 July.
For an idea of a typical day at the transmit site in Bolinas (BL) read Bill Ruck's report Below:
 Bill Ruck directs maintenance operations in the transmitter gallery at Bolinas
Transmitter Supervisor Hawes reported high reflected power on the PW-15. Then RFI on the telephone line made it hard for RS to connect so SH switched back to the Henry for 12 Mc/s.
Went out into the field and walked the line. No problems until I got to the end. Looked like something across the transmission lines. On closer inspection the 6 Mc/s dipole was down and shorting the 12 Mc/s feed line. SH reported that the 6 Mc/s transmitter was in service. Wonder how well it was working with half of it (and the feed point) in the grass.
After inspection the west end support cable was once steel but now mostly iron oxide and iron salts. Broke off at the west pole end. The east side support cable is 7 strand copper and looks OK. The only potential issue is that the 7 strand antenna wire has a few kinks now that should be straightened out before we put it back up.
 | | MRHS video of antenna maintenance at Bolinas. See Service car 50 in action! |
On the way back noticed that the guy wire on the end of the east transmission line supports near the first row was lying across the feed lines. These are not in service now since the tree took out the lines. I was able to move that guy wire off of the lines and wrapped it around the pole. Also very little metal left; mostly iron oxide. That pole is leaning a little and would be good to replace the guy.
Re: 6 Mc/s antenna. We have one only offset dead end for #8 stranded wire in stock. Used up our stock repairing the 22 Mc/s antenna last fall. Was going to order a new box after VIP funds were available last year but that didn't happen. Will order a box Monday and should have it the following week.
Need to schedule Nick and his Pacific Antenna Repair crew. The ground is hard and dry up high and only soggy in the valleys. Believe that it is possible to drive from the road to both the 22 Mc/s and 6 Mc/s antennas with Nick's truck.
RK
Any idea how much it's going to cost to repair the antennas and feed lines? Right, we don't know either. But it's going to be in the thousands, that's for sure. Even now several transmitters are off the air for lack of an antenna. And on Night of Nights 2014, coming up on 12 July, we'll need every antenna we have.
If you can help with a contribution to help fund the repairs just click on the donation button below. Every donation helps, every donation is tax deductible and every donation will be very, very deeply appreciated.
> MRHS Merchandise
When you show up at International Marconi Day 2014 make sure you stand out as a True Believer by sporting a MRHS hat, T shirt or hoodie. Or even a MRHS belt buckle. While sipping coffee from a MRHS mug!
Support the MRHS and look cool at the same time. Such a deal! We've got hats, mugs, T shirts, belt buckles and bumper stickers, all with variations of the MRHS logo. Get a hat and mug for yourself and a put yourself in solid with the XYL by getting her a MRHS hoodie.
Just click on the images above to go to the MRHS True Believers store and browse our offerings.
Thanks!
Until next time we wish you fair winds and following seas.
VY 73,
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