[CW] Night of Nights 2016! - MRHS Newsletter No. 55
Maritime Radio Historical Society
n1ea at arrl.net
Wed Jul 6 15:35:03 EDT 2016
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MRHS Newsletter No. 55
Dedicated to True Believers Worldwide
Special Night of Nights Edition
6 July 2016
Newsletter back issues click HERE [http://r20.rs6.net/tn.jsp?f=001M4Z6ZRkTiBMWA-pMdMmhQPUJUVMMys7_l3p8vsxbjtu4mGggZyZI70PlxhLnuQ0t2oRs8SjoFnv_nG-xSbws3jP1S-l_tX2DJO55PhIOuypHiKNJq8LJnG05VbXF6PdZCxg-blyLJJd3dy_e65cD8bK-3YFTRoOcf_mIF6l1OVVARk3X7Bx1Ds1mC0LIVIIaQqaY5_GiOs2oEurcKTSMTdxj-j147aanRKPHCnEuh0tjB4pp8tv6UsTOoopHSdXu&c=WmlMFNRZReARmZ03KzI6Xlu0rYUWBZH9p9iiyvny2Ogq9e2Mt7eB2Q==&ch=yLv2MHXXD47VCVe7VNfTBFIX4WcNW3_xh_s4CDzltbTKEIZ2xlkThA==]
MRHS Web site click HERE [http://r20.rs6.net/tn.jsp?f=001M4Z6ZRkTiBMWA-pMdMmhQPUJUVMMys7_l3p8vsxbjtu4mGggZyZI745Qhx7oBSSavqzwL-_mt9XGp6QtCaqJq9UcTwcfF6zM4rWUptqQbn3lUGfpuQvrNsyxEU3Xw5SMEzTzBJk8-CQXf6XGVHpkpp62RBs5y9HE-1rU4e7n_Lw=&c=WmlMFNRZReARmZ03KzI6Xlu0rYUWBZH9p9iiyvny2Ogq9e2Mt7eB2Q==&ch=yLv2MHXXD47VCVe7VNfTBFIX4WcNW3_xh_s4CDzltbTKEIZ2xlkThA==]
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Basic Event Enformation:
Date: 12 July 2016 Pacific Daylight Time
First Transmission form MRHS Stations: 5:01pm Pacific Daylight Time 12 July, 0001Z
13 July 2016
Full details below
> Historic coast stations KPH, KFS, KSM, and WLO will be on the air!
> USCG stations NMC, NMW and NMQ will return to the air - possibly for the last
time!
> RCA "H Set" Transmitter 298 will be on the air (KSM 22Mc)
> 1942 Press Wireless PW15 transmitter will be on the air (KFS 12Mc)
> K6KPH will be listening for calls and signal reports
> W4WLO will be listening for calls and signal reports
> Join us in person or on the air!
But wait, there's more:
> Technical report on the RCA SSB R3 diversity receiver
> The enigmatic H over 2 antenna explained
> Frank Geisel's Report No. 3 for June/July 1946
> Welcome New Readers!
Even though the MRHS Newsletter appears only irregularly these days True Believers
continue to subscribe. Please accept our thanks and warm welcome. We hope to see
you in person at this year's Night of Nights.
> Support the MRHS
Those who have joined us for past Night of Nights events - in person or on the air
- know how much it takes to keep the transmitters transmitting, the receivers receiving
and, most especially, the antennas in the air. It is only through contributions
from True Believers like you that we have been able to keep the project going since
1999. If you can help us again on Night of Nights XVII please click on the yellow
button below. We promise to use every dollar you donate in the best way possible
to keep the stations under our care on the air!
Make a Donation [https://www.paypal.com/cgibin/webscr?first_name=&last_name=&undefined_quantity=1&[email protected]&image_url=&return=http://www.radiomarine.org&cancel_return=&item_name=Support%20the%20MRHS&amount=0&shipping=0¤cy_code=USD&item_number=&cmd=_xclick]
> Night of Nights 2016 (XVII)!
It's that time of year again. Time to honor all those ops who came before us by
preserving their skills, traditions and culture through on the air operations.
Why 12 July? Long time True Believers know the story. But it may be worth repeating
for new arrivals and to remind everyone of the traditions we hope to keep alive.
On 12 July 1999 some very tough looking grizzled old radio pioneers had tears in
their eyes as the last commercial Morse code radiogram was sent. It was the end
of an era. And as the last beeps faded away into the static they witnessed the
end of the career to which they had devoted their lives.
Paul Zell sends the last commercial Morse messages at KFS/KPH - or so it was thought
These men - and some women - had stood watch over the airwaves on shore and at
sea. Theirs was mostly the business of maritime commerce. But when their ship
was in peril they were called upon to send the most electrifying three letters
in radio, S O S, knowing that all their fellow radio operators would press their
earphones close to get every scrap of information and bring aid to their stricken
ship.
Once, our coasts were dotted with great Morse code radio stations, all communicating
with ships at sea. They're all gone now... all except one, the one they called
the Wireless Giant of the Pacific, located at Point Reyes.
On that sad day in 1999 another event took place. The Maritime Radio Historical
Society (MRHS) was formed. We made it our life's work to honor the men and women
of wireless by restoring that wireless giant. One year and one minute later the
giant's voice once again spanned the oceas as we picked up the thread and kept
the faith with our colleagues of the air.
Every year since, in an event that became known as the Night of Nights, Morse code
station KPH has returned to the air, joined by KFS and the station of the MRHS,
KSM.
This year our friends and colleagues at USCG station NMC have labored mightily to
bring that storied call sign back to life on Morse code for the evening along with
NMQ in Cambria, CA. And station NMW in Astoria, OR will be on the air as well.
Station WLO will join us again as they have in years past.
This is a global and local event. Hundreds of listeners around the world will
be waiting with their earphones on, waiting for the signals of the great station
to once again arc over the dome of the Earth to their receivers.
You can be with us in person!
Dozens of people will join us at the RCA receiving station in the Point Reyes National
Seashore to watch as the signals are transmitted by hand using vintage telegraph
keys.
A guest operating position will be available so bring your key and 'phones or use
ours and operate K6KPH. No license required! So if you're an ex-commercial op
who never became a ham here's your chance to sling some Morse again. Or if you
hold a current commercial radiotelegraph ticket you can operate KPH, KFS and/or
KSM and have your license endorse to that effect.
This year we will have our custom made endorsement stamp available to add that special
touch to your ticket.
Chief Operator Richard Dillman at Position 1
Date: Friday 12 July 2016 Pacific Daylight Time
Location: RCA receiving station, 17400 Sir Francis Drake Blvd., Point Reyes National
Seashore
Click HERE [http://r20.rs6.net/tn.jsp?f=001M4Z6ZRkTiBMWA-pMdMmhQPUJUVMMys7_l3p8vsxbjtu4mGggZyZI7-xsYOiLkuz5jgUQCyCuNR3fGJRKGM5E3p-Qh_sfGnMOCw-5l4eoU8E3BnAxU_CU9GAD_cBUllutCnVGlcht8O1pR2MdPMhEjOWCmG9hhsyrWLnbu0dAmPTSKCuumnsolA==&c=WmlMFNRZReARmZ03KzI6Xlu0rYUWBZH9p9iiyvny2Ogq9e2Mt7eB2Q==&ch=yLv2MHXXD47VCVe7VNfTBFIX4WcNW3_xh_s4CDzltbTKEIZ2xlkThA==]
for a map of the location from Google Maps
Time: Doors open at 3:00pm pdt, first transmission 5:01pm pdt (0001gmt 13 July)
Refreshments: Served
Photographs: Encouraged
Tours: Given
None of this would have been possible without the trust and vision of the Point
Reyes National Seashore [http://r20.rs6.net/tn.jsp?f=001M4Z6ZRkTiBMWA-pMdMmhQPUJUVMMys7_l3p8vsxbjtu4mGggZyZI77_QNl7Iw5P6cdK-vlmEKG1Wtv8B3X2aGJs91iYYlYO3ps27Xa4gFCKSJo495B9fvh6seF_LGpI6RbV-q-1xvrL1oA_AOjlzlA2uM3ulSLDSAWqE4bCW_WwVgb-bDE0KvuS5CzzpMjiV&c=WmlMFNRZReARmZ03KzI6Xlu0rYUWBZH9p9iiyvny2Ogq9e2Mt7eB2Q==&ch=yLv2MHXXD47VCVe7VNfTBFIX4WcNW3_xh_s4CDzltbTKEIZ2xlkThA==].
The only reason these facilities were spared the bulldozer that visited all the
others is that they are on park land. And the only reason they have been restored
to operation is that the PRNS staff understood their importance and trusted the
MRHS to restore them to life.
NOTICE: All the information below is subject to last minute change as final arrangements
are made. Keep up with the latest details by following us on Twitter [http://r20.rs6.net/tn.jsp?f=001M4Z6ZRkTiBMWA-pMdMmhQPUJUVMMys7_l3p8vsxbjtu4mGggZyZI7wvebSjfZrphP9CoeZeqWEImSY-TCjiTL7dUg7exRU2_qsBELdrQIzedqSMBCk4Ql8abTAT4ePRvFIp-x3cneXe43hl-IFTWvZ08ZZljj_2cEgIYY_IBbq8=&c=WmlMFNRZReARmZ03KzI6Xlu0rYUWBZH9p9iiyvny2Ogq9e2Mt7eB2Q==&ch=yLv2MHXXD47VCVe7VNfTBFIX4WcNW3_xh_s4CDzltbTKEIZ2xlkThA==]
@Radiomarine and by subscribing to this Newsletter if you are not already a reader.
MRHS Stations
Eighteen transmitters will be on the air from the MRHS transmitter site in Bolinas!
That doesn't include transmitters held in ready reserve in case of failure. Members
of the crack MRHS Transmitter Department and the H Set Team will be on hand to assure
that all goes well.
> KPH:
Frequency Transmitter Antenna
500/426 Henry MF-5000D Marconi T
4247.0 RCA K Set Double Extended Zepp
6477.5 RCA K Set Double Extended Zepp
8642.0 RCA L Set Double Extended Zepp
12808.5 RCA L Set H over 2
17016.8 RCA L Set H over 2
22477.5 RCA H Set H over 2
The restoration of the H set has been chronicled in past issues of the Newsletter.
See Newsletter No. 38 [http://r20.rs6.net/tn.jsp?f=001M4Z6ZRkTiBMWA-pMdMmhQPUJUVMMys7_l3p8vsxbjtu4mGggZyZI74_xVRuUfjMPDF1cDWZubulTozd7uxDfKHARnPyB3HXkJwHTdF4lxzHjdluZYlBiWJZU7UhDSDJcWKw9QEvA9sHc8itnlUjq-huMmFYnE8Tkf45HMer4zjWwVIxJCJx-veQWIv2Q2RC808EGQNPyPs1QcmpmLSk7tdQFrYcgWLDElUkmuFzxg4c-ws5Lqt-p8QPCKDJUok2L&c=WmlMFNRZReARmZ03KzI6Xlu0rYUWBZH9p9iiyvny2Ogq9e2Mt7eB2Q==&ch=yLv2MHXXD47VCVe7VNfTBFIX4WcNW3_xh_s4CDzltbTKEIZ2xlkThA==]
for information about and photos of this magnificent transmitter.
> KFS
Frequency Transmitter Antenna
12695.5 Press Wireless PW15 H over 2
17026.0 Henry HF-5000D H over 2
> KSM
Frequency Transmitter Antenna
500/426 Henry MF-5000D Marconi T
8438.3 Henry HF-5000D Double Extended Zepp
12993.0 Henry HF-5000D H over 2
16914.0 Henry HF-5000D H over 2
Verification card for K6KPH. A similar card is available for KSM. Both were designed
by Paul Shinn
> K6KPH
K6KPH ops will monitor the frequencies below as propagation and the number of available
operators permit.
Frequency Transmitter Antenna
3550.0 Henry HF-5000D Double Extended Zepp
7050.0 RCA L Set Double Extended Zepp
14050.0 Henry HF-5000D H over 2
18097.5 Henry HF-5000D H over 2
21050.0 Henry HF-5000D H over 2
> Reception Reports
Reception reports and verification requests for the MRHS stations listed above may
be sent to:
Maritime Radio Historical Society
PO Box 392
Point Reyes Station, CA 94956
USA
> Station Telephone
The receive site may be contacted by phone on 415-669-9646
USCG Stations
NOTICE!
We said this last year but dedicated USCG personnel have once again pulled off the
impossible and brought these historic stations back to life on CW. Nevertheless,
this may very well be the last time ever that USCG stations can be heard on the
air using A1A (Morse) emission. As new equipment is installed the hardware and
wiring for Morse has been progressively removed. And the personnel who knowledgeable
in the art retire or are reassigned. So be sure to listen for these stations.
Many USCG personnel at all levels are responsible for bringing these stations back
on the air for Night of Nights 2106. We want to particularly thank ET1 Mike Leska
for taking the lead for this year's project.
NMC/NMQ verification card from Night of Nights 2014
> NMC (Transmit Bolinas, Receive Pt. Reyes)
Frequency Transmitter Antenna
472.0 (or 448.0 Nautel ND2500TT/6 173' monopole tower
6383.0 Rockwell-Collins RT-2200 Omni-directional
8574.0 Rockwell-Collins RT-2200 Omni-directional
17220.5 Rockwell-Collins RT-2200 Omni-directional
NOTE regarding NMC/NMQ/NMW MF transmissions. Only one MF transmitter will be in
service at each station. Morse transmissions will be made on an as-available basis
from each station as USCG operators must also accommodate scheduled NAVTEX transmissions.
> NMQ (Transmit Cambria, CA, Receive and Control Pt. Reyes)
NMQ Transmitters
Frequency Transmitter Antenna
448.0 Nautel ND2500TT/6 Inverted L
472.0 Nautel ND2500TT/6 Inverted L
500.0 Nautel ND2500TT/6 Inverted L
> NMW (Transmit Astoria, OR, Receive and Control Pt. Reyes)
Capacitive top hat transmitting antenna at NMW
Frequency Transmitter Antenna
448.0 Nautel ND2500TT/6 Capacitive top hat
472.0 Nautel ND2500TT/6 Capacitive top hat
500.0 Nautel ND2500TT/6 Capacitive top hat
> Reception Reports
There's a new address for USCG reception reports:
ET1 Mike Leska
ESD Ketchikan/NMC QSL Manager
1300 Steadman Street
Ketchikan, AK 99901
Special Request: ET1 Leska is funding the verifications of USCG stations out of
his own pocket. Please help him out with a small donation and a self addressed
stamped envelope when you send in your report. He'll appreciate it.
Shipcom LLC WLO
All thanks to Rene at WLO for the work he does each year to bring WLO back on the
air. He is a true radiomen.
> WLO
4343.0
8658.0
12992.0
16968.5
> Reception Reports
Via email to: rene at shipcom.com
> W4WLO
Here's great information just received from Rene Steigler of WLO:
We will activate W4WLO ON 40 and 20 meter CW for Night of Nights.
7055
14055
Be sure to listen for W4WLO and give them a buzz.
> Calling Channels
All commercial and USCG stations listed above will listen for calls from ships on
500kc and on ITU Channel 3 HF:
4184.0
6276.0
8368.0
12552.0
16736.0
22280.5
Listen on these frequencies if you want to copy both sides of ship to shore contacts.
> Commemorative Messages
Was your father, uncle or grand dad a commercial op or amateur operator? Would
you like to send a commemorative message in their honor over KPH, KFS and KSM?
We have sent several of these messages in past events and they were all very moving.
If you would like us to send such a message this year please send it to us no later
than Wednesday 9 July pdt so we can be sure to include it. Sent it to info at radiomarine.org
> Technical report on the RCA SSB R3 diversity receiver
It will be remembered by faithful readers of these pages that the receive site we
currently use in Point Reyes (RS) was in fact built for the trans-Pacific point-to-point
service. When that service ended in 1973 all the magnificent diversity receivers
were junked. As a result we had no hardware of the point-to-point service to show
visitors. But last year we received word that all the components for a complete
RCA SSB R3 receiver existed in Germany. We quickly made contact with the seller
and arranged for everything to be crated and sent to us by ship. The crate duly
arrived.
Steve Pazar, a wonderfully talented MRHS member, has taken on the job of restoring
this magnificent receiver. Here's Steve's report on his progress and on the SSB
R3 itself. As Steve says, "buckle your seat belts." As will soon become apparent,
this baby ain't no Icom!
A milestone of sorts was reached the morning of June 4, 2016 when the first signals
passed through the front end of our R3. Probably for the first time in many decades.
This project had its beginnings while we were restoring the RCA H-set (aka T3) transmitter.I
wondered if RCA built a matching receiver and soon discovered the R3. Since then
I've been searching for information and components. We now have all of the bits
and the restoration is underway. These receivers were originally used at RS for
point to point service. For an overview of this receiver take a look at Newsletter
No. 16 [http://r20.rs6.net/tn.jsp?f=001M4Z6ZRkTiBMWA-pMdMmhQPUJUVMMys7_l3p8vsxbjtu4mGggZyZI793Ex4gFK5itov2X-gz3v4FqYdpFqQoSlWMduvcMlfBQtM54ieOgkwRsgWs--l_4fmuxdNYJ0-8lZlSWdpfDeJx4g0_TEPbyJDM5AZN18029bAaHCm22pEQYJOHLehAEFwL8UUzsO8PPi0-qUUWOiQS2fDY7M68AxqmQXBCRZY4_e7U295er9BufgT9-pegESgN-vaK29V2i&c=WmlMFNRZReARmZ03KzI6Xlu0rYUWBZH9p9iiyvny2Ogq9e2Mt7eB2Q==&ch=yLv2MHXXD47VCVe7VNfTBFIX4WcNW3_xh_s4CDzltbTKEIZ2xlkThA==]
and Newsletter No. 19 [http://r20.rs6.net/tn.jsp?f=001M4Z6ZRkTiBMWA-pMdMmhQPUJUVMMys7_l3p8vsxbjtu4mGggZyZI70BUjl3yzxseVgsNqLV-ijF6eFYTPgXSYyrsfI0fGnvDhiFmvr7K_n_mEvyL8DE_Y-W9N8e2UFJ3AFINJP_L5aD-UUIE2BHxOXm2CSEVJGcNi2wtLxBY2llcB8GS9lFx3bjV5gsgyjePEyTRAT7zAdG0_f1MN1-xhjme8NQhmFbt8whX6XwDfzp6nDt9RIwwH605baNNlp53&c=WmlMFNRZReARmZ03KzI6Xlu0rYUWBZH9p9iiyvny2Ogq9e2Mt7eB2Q==&ch=yLv2MHXXD47VCVe7VNfTBFIX4WcNW3_xh_s4CDzltbTKEIZ2xlkThA==].
In this article I will describe the design of the two amplifier/preselctor modules
and the captive oscillator. The latter is the VFO for the receiver. These can be
seen in the picture.
The R3 is an independent sideband, dual diversity receiver covering 2.8 to 28 MCin
four bands. It is a dual conversion receiver with a first IF of 1 MC and a second
IF of 100 KC.
RF Amplifier/Preselectors (units 200 and 300)
The R3 operates in four bands; 2.8 - 5 MC, 5 -9 MC (unit 200) and 9 - 16 MC, 16
- 28 MC (unit 300). Each band has two identical, tracking RF amplifier sections
(4 tuned circuits, 3 amplifiers each) as well as a mixer and tuned IF buffer amplifier.
The mixer takes the output of the preselector and mixes it with the output of the
receiver VFO(Captive Oscillator). The VFO operates 1 MC higher than the signal being
received which results in the first IF output of 1 MC. See figure 1 for the block
diagram.The input transformer for each of the eight preselectors can be configured
for either 50 or 200 ohm antennas.
The bands are selected via a switch on the Captive Oscillator (unit 400T). As each
band is selected the appropriate filaments in the preselectors are lit. Note that
the preselectors have 36 tubes in all but only 1/4 are lit at the same time.
Captive Oscillator (unit 400T);
As mentioned this is the VFO for the receiver and its output is 1 MC higher thanthe
signal being received. This is the second version of this unit, the first used tubes.
Ours uses germanium transistors, hence the "T" after the 400 designation. This is
by far the most complex module in the R3. At least from a design point of view.
The circuit contains elements of a Wadley loop and a phase locked loop.
See figure 2.
In an effort to simplify the description, let's break down this unit into a few
key parts;
* captive oscillator (Q5) and buffer amplifiers (Q1 thru 3)
* 1 MC xtal oscillator and harmonic generator (Q10 thru 14)
* master oscillator and amp (V1,2 and Q9)
* phase detector and frequency control (CR1,2 and CR 8,9)
The captive oscillator is a voltage controlled oscillator and it generates the output.Its
range is 3.8 to 29 MC. The three buffer amps, Q1 thru 3, provide isolation and a
low impedance to the mixers in the preselectors.
The 1 MC oscillator and the harmonic generators that follow it generate integer
multiples of 1 MC from the 6th to 31st harmonic. These harmonics are selected via
the "MC" knob on the front panel. This switch selects one of each set of tuned circuits
(3 per integer frequency) in the 3 harmonic amp stages. That'sa total of 26 times
3 or 78 tuned circuits!
The master oscillator is a special Collins PTO operating from 2 to 3 MC. It is in
a temperature controlled oven. This is the "KC" knob on the front panel.
The phase detector (CR1,2) output drives a pair of varactor diodes (CR8,9)which
in turn tune the captive oscillator (Q5).
OK, now I'll try to bring all of the parts together. Buckle your seat belts!
For an example of basic operation, lets say the Captive Oscillator (as a unit) is
tuned to receive "10.000 MC". This means Q5 should be running at 11.000 MC. Under
these conditions the 13th harmonic of the 1 MC xtal oscillator is selected, so the
output fromQ14 is 13 MC. The master oscillator (Collins PTO) will be at the low
end of its range (2 MC), which corresponds to a "xx.000" front panel frequency selection.
So we have the captive oscillator output (11 MC) which is buffered by Q4 and 5being
mixed (Q7) with the 13 MC output from Q14 which results a frequency of2 MC (a LPF
eliminates the higher mixing product) at the output of Q8 which act as a buffer
amp. This is compared to the 2 MC output of the PTO (via Q9) in the phase detector
that is comprised of CR8 and 9. If everything is exactly on frequency the output
of the phase detector will be zero and the captive oscillator will remain at 11
MC.The system is locked and will provide a very stable frequency output.
Now to confuse you even more, I did not mention two things. The captive oscillator
(Q5) must be pre-tuned to be within lock range of the frequency you'd like to receive.
Remember this is a very wide range oscillator (3.8 to 29 MC). This control is on
the far left side of the Captive Oscillator front panel.There is also a zero center
meter on the front panel. This displays the DC output of the phase detector.
Now lets modify our example a bit and say we want to receive 10.050 MC. In this
case we'd move the "KC" dial to "050". The PTO output will be at 2.050 MC.If everything
else is left set the way they were at 10.000 MC the system will still be locked
but we will see a positive offset voltage from the phase detector as displayed by
the meter. At this point we could re-tune the captive oscillator to achieve zero
output from the phase detector but it is not always necessary. The range of 'capture'
of this phase locked loop system is quite broad but it does change from band to
band. Curves for the captive range versus frequency/band are included in the manual.
For this example the locking range is approx. +80 KC to -120 KC.
Extending this example even further you can see how the Captive Oscillator can tune
across its entire range in 1 MC continuously tuned ranges. The captive oscillator
will need to be re-tuned when phase lock is lost. With a little practice this is
quite easy.
>From an operators point of view the R3 receiver VFO can remain locked, and thus
maintain excellent frequency stability even if 'tuning around' a bit. Now to add
to the fun of tuning this beast, the operator also needs to peak the preselector.
One quick word about a problem with the Captive Oscillator design. Its frequency
stability is dependent on two things; the 1 MC xtal oscillator and the Collins
PTO. Both are in temperature controlled ovens and should be very stable once at
operating temperature. However an external variable capacitor was mounted on the
front panel that is used to make minor frequency corrections to the PTO. Its capacitance
can change with ambient temperature and in fact I did see this on the bench. Not
much drift but certainly noticeable. As a result I will be including a frequency
counter in the racks to monitor the output of the Captive Oscillator to let the
operator know exactly what frequency he is listening to.
More to follow as the remaining units of the R3 are electrically restored and integrated
into the receiver.
Steve Pazar
-----
Special Note: Steve is in need of two racks appropriate for the R3 components to
complete the restoration project. These are not normal equipment racks since he
components are not supported by the front rails in the usual manner. Take a look
at the photo at the beginning of this article for an idea of what's needed. Then
read Steve's information below. If you think you can help please send us an email
at info at radiomarine.org and we'll pass your information along to Steve.
For this project we need two, matching six or seven foot racks. 19" type.
No front doors. Back doors would be nice but not necessary.
They should have side panels and the ability to be bolted together.
The depth (from front to back rail) should be at least 16" but no
greater than 20". 18" seems to be a 'standard' shallow rack depth.
The front rail hole spacing does not matter.
A key requirement is these racks must have internal rails to allow for
slides and/or shelves to be be mounted.
Not bent or rusty and preferably with serviceable paint.
Racks that will not work;
HP or modern style racks
24" deep racks (this is a standard type)
racks where the side panels are rolled over to become the front and rear
rails
racks that are bolted together rather than welded (many server racks are
like this)
frame racks that have no sides or back rails
We will also need at least 12 matching, electronic equipment sliding rails.
This will be really tough to find and won't know what types will work unitl
we get
the racks. Do not want to skimp on these. If no slides are available
we will have to fabricate shelves for the R3 modules. These do not mount
to the rack via the front panels like most 19" rack equipment but originally
depended on the sliders to mount firmly in the racks.
> The enigmatic H over 2 antenna explained
By Kevin McGrath
If you have worked K6KPH, you may have heard the op say "TX ANTENNA HR IS H/2".
Or perhaps you have read on the MHRS website that KSM and K6KPH both use H/2 antennas.
But what exactly is an "H over two" antenna?
Searching the internet does not provide any clues. Crawling through the US Patent
Office database for RCA antenna patents (there are dozens!) doesn't help either.
And Googling "H/2 antenna" or "H over two antenna" simply points right back to
the radiomarine.org website, which has few details - until now, that is! Read on...
The H/2 Antennas at KSM
Coast station KSM/KPH uses H/2 antennas on 12, 16 and 22 Mc. (Double Extended Zepp
antennas are used on 4, 6 and 8 Mc). Eleven H/2 antennas are located the 30-acre
south antenna field at the KSM transmitter site in Bolinas, CA. The H/2s, like
all antennas at Bolinas (BL), are only used for TX. (The KSM RX site, located 15
miles north of BL on Point Reyes, uses TCI omnis, rhombic and vee-beam antennas.)
The K6KPH amateur operation uses the original KPH transmitters, receivers and antennas
- including some H/2s. On 14 Mc, K6KPH uses a 12 Mc H/2, and on the 18 Mc and 21
Mc bands a 16 and 22 Mc H/2 respectively are used.
H/2 Construction and Theory
In some ways, an H/2 resembles an extended version of the well-known Lazy-H antenna.
More precisely, the H/2 is a broadside array of stacked collinear dipoles in which
four collinear dipoles are stacked one-half wavelength over another set of four
collinear dipoles. All eight dipoles are fed in-phase using a unique feed system.
The H/2 is a broadside radiator with bidirectional directivity at right angles to
the line of the line of the array.
The gain of an H/2 array is 8.75 dB over a single dipole positioned at the same
height of the upper wire.
Figure 1 KPH H/2 Antenna
It is hard to get a good photo of a large wire antenna in the field, so you'll have
to imagine the antenna in Figure 1 being supported by two 90' utility poles - one
on each end. At 16Mc, the total length of an H/2 array is 117' (2 wavelengths) and
the spacing is 29.25' (one-half wavelength). Seven-strand #14 copper wire is used
to construct the array and the phasing stubs.
Arrays of collinear dipoles like the H/2 are operated with the elements in-phase,
such that the fields from each element combine at a distant point in an additive
manner. The inner two elements are directly connected to the feedline and thus
are naturally in-phase. However some care must be taken to keep the two outer elements
in-phase. Since the direction of current flow reverses in each l/2 section, the
outer elements can't simply be connected end-to-end with the adjacent inner elements.
The ¼ wavelength phase reversing stubs between the inner and outer collinear elements
serve to bring the currents of the outer elements in-phase.
Starting at the bottom, the feedline brings power to the lower set of elements.
Because the upper and lower sets of elements are spaced by l/2, the half-wave length
of phasing line supplies 180 degrees of phase shift. A half- twist in the phasing
line supplies an additional 180 degrees of phase difference, such that the top and
bottom sets of elements are now fed in-phase.
An interesting detail is that the upper and lower stubs are not insulated from each
other! Since the ends of each stub are at the same RF potential, they can be connected
together thus simplifying construction. In fact, the stubs are formed using single
piece of transmission line running from the upper dipoles to the bottom dipoles,
with shorting bars located at .95 *l/4 from each dipole (.95 being the velocity
factor of the transmission line).
The resulting bidirectional radiation pattern is broadside to the array shown as
shown in Figure 2.
Figure 2 H/2 azimuth plot
The H/2 antennas at KSM are supported by 90' wooden utility poles. At 16 Mc, that
puts the H/2 upper elements at 1.5 l above ground and the lower elements at 1l above
ground. The resulting main lobe takeoff angle is 11 degrees. The elevation plot
is for a 16 Mc H/2 at a height of 90', modeled over a good ground.
Figure 3 H/2 elevation plot, H (top wire) = 1.5 WL (90')
Most of the H/2 antennas at BL are oriented so that the one of the main lobes is
aimed WNW (300°) to cover shipping in the northern and western reaches of Pacific
Ocean. (The other lobe at 120°would cover any South American banana boats!) Given
their narrow beamwidth, these H/2s are not optimal for coverage of North America.
However, the particular H/2 that K6KPH uses on 20M is aimed at 60° and provides
good coverage of much of the US.
The Care and Feeding of H/2 Antennas
The H/2 antennas are fed with 600-ohm open wire line. This line is constructed with
a pair of #4 hard-drawn copper wires on 11.5" centers. Since the characteristic
impedance of the H/2 is relatively high, about 1400 W, tuned stubs are used to provide
a better match to the feedline. A well-matched line makes for an easier job of matching
the line to the transmitters. Furthermore, at KPH power levels (and given the moisture-laden
salt air at BL), minimizing SWR is also important in order to reduce high voltage
nodes on the feedline which might cause corona discharge or arcing across any dirty
insulators.
Figure 4 An H/2 Tuning Stub (from the Chief Engineer's files)
The precise position and length of a matching stub, and thus its impedance transformation
characteristics, are a function of the SWR and location of current nodes on the
unmatched line. At KSM, the SWR and location of current nodes are found by using
a specially-designed transmission line sled (Figure 5). The sled is instrumented
with pickup loops and two RF ammeters. By observing the ammeters as the sled is
pulled along the open wire transmission line, the SWR can be calculated and current
nodes are located. From these two values, the required length and position of the
matching stub are determined by consulting a chart found in the Chief Engineer's
files.
Figure 5 KSM Transmitter Supervisor Steve Hawes holds the tuning sled
The transmitters at KSM consist of 22 1990's era Henry HF-5000D unit plus older
RCA and Press Wireless sets. The "modern" HF-5000D transmitters are designed to
operate into approximately 50-ohm unbalanced loads. Custom made link-coupled matching
networks are used to match the 600-ohm feedline to the HF-5000Ds and provide the
necessary balanced-to-unbalanced transformation. A breadboard prototype of the
matching network still hangs on a wall in the Chief Engineer's office.
Figure 6 Prototype of Matching Network
Maintenance needs
KPH closed in 1997, hence the antennas at the Bolinas site at least 19 years old.
Some are probably older. The H/2 drawings from the Chief Engineer's files are dated
anywhere from 1957 to 1991. In addition to their age, salt air and winter storms
take a toll on the KSM antennas. Currently, one of the 22 Mc H/2 antennas is offline
due to a bad phasing line. A 4Mc and 8Mc EDZ are offline caused by falling tree
branches or parted support wires.
In the past, the antennas at KPH were maintained by a full-time crew of professional
riggers. Now, MHRS volunteers must handle the task. See MHRS Newsletter No. 22
[http://r20.rs6.net/tn.jsp?f=001M4Z6ZRkTiBMWA-pMdMmhQPUJUVMMys7_l3p8vsxbjtu4mGggZyZI790ypiT0_vwcmBnQHX1jpkF-rOxlCM6VfwFuGjzo5iOqfZ1cA6gMHP8WruRyHav5STuqJ3lgoR1gRDlPYAHE8BjkseNv6YqZieCHsYY7UTKhPFzbUu0eSEDQOVyxjhpq9HLkoGm_zKG1OLZli1hDRXJsBN-Ig1Y-7Ai9adYV6IsXuw7qKX4voxZjNT5N4CU6UpJQM258bzhE&c=WmlMFNRZReARmZ03KzI6Xlu0rYUWBZH9p9iiyvny2Ogq9e2Mt7eB2Q==&ch=yLv2MHXXD47VCVe7VNfTBFIX4WcNW3_xh_s4CDzltbTKEIZ2xlkThA==]for
an example antenna work done by our intrepid volunteers. However for any work done
at height, professional riggers and a man-lift are required. You can help by donating
to the MRHS! Without your contributions we could not fund the purchase antenna hardware
or afford the rigging services needed to keep the KSM antennas on the air.
-----
Mr. McGrath speaks the truth. Our biggest challenge is not, as some would suspect,
the restoration and maintenance of transmitters more than 70 years old. No, it's
the antennas. As any radioman knows it's a lot of work to keep the skywires aloft.
In our case it's dozens of antennas at two sites. One of the enigmatic H over
2 antennas he describes is on he ground at Bolinas, preventing us from activating
one of our three RTTY frequencies. We have to hire on special crews to do this
work as shown in Newsletter No. 22 [http://r20.rs6.net/tn.jsp?f=001M4Z6ZRkTiBMWA-pMdMmhQPUJUVMMys7_l3p8vsxbjtu4mGggZyZI790ypiT0_vwcmBnQHX1jpkF-rOxlCM6VfwFuGjzo5iOqfZ1cA6gMHP8WruRyHav5STuqJ3lgoR1gRDlPYAHE8BjkseNv6YqZieCHsYY7UTKhPFzbUu0eSEDQOVyxjhpq9HLkoGm_zKG1OLZli1hDRXJsBN-Ig1Y-7Ai9adYV6IsXuw7qKX4voxZjNT5N4CU6UpJQM258bzhE&c=WmlMFNRZReARmZ03KzI6Xlu0rYUWBZH9p9iiyvny2Ogq9e2Mt7eB2Q==&ch=yLv2MHXXD47VCVe7VNfTBFIX4WcNW3_xh_s4CDzltbTKEIZ2xlkThA==],
and this costs money. That's why we ask you to help us with a donation. Every
penny will go to keeping the stations on the air. And it's easy! Just click on
the yellow button below. Thanks!
Make a Donation [https://www.paypal.com/cgibin/webscr?first_name=&last_name=&undefined_quantity=1&[email protected]&image_url=&return=http://www.radiomarine.org&cancel_return=&item_name=Support%20the%20MRHS&amount=0&shipping=0¤cy_code=USD&item_number=&cmd=_xclick]
> Frank Geisel's Report No. 4, August 1946
Beginning in Newsletter No 49 [http://r20.rs6.net/tn.jsp?f=001M4Z6ZRkTiBMWA-pMdMmhQPUJUVMMys7_l3p8vsxbjtu4mGggZyZI78dNuGjDLuiMrotW76ka6mQlokrplECqkCiD8Bx6Wk-po32Jlul77HJOoKa7tHyyffoLBoKzJiuRz78rZmtdstObjtEfaz7EOxPZB0FI7NQTVncCq6sWa4cR4nbM1zSk_QX858JbPoSNiEnfodkZyg3f4r8n7nCEJ1h6MSSgXjgNaTwb3BBm1256Vg_o5F1JowM-4etsQwT9&c=WmlMFNRZReARmZ03KzI6Xlu0rYUWBZH9p9iiyvny2Ogq9e2Mt7eB2Q==&ch=yLv2MHXXD47VCVe7VNfTBFIX4WcNW3_xh_s4CDzltbTKEIZ2xlkThA==]
we began presenting FG's KPH reports from the years immediately following WWII after
the station was re-opened for commercial service. Let's look in at his report for
August 1946.
Line trouble continues with outages on the line to the transmit site in Bolinas
and the WU line. In classic FG style, he complains about the "ancient, decrepit,
Marconi equipment" he has to deal with, a story that continued throughout the history
of KPH. Nevertheless the station soldiered on, providing good service in spite
of QRM and personnel problems. One important thing to note is that FG is anxiously
awaiting the arrival of Mr. Meloney. That would be Bill Meloney who survived being
torpedoed twice as a radio officer in WWII and became the most beloved and best
Morse operator KPH ever saw.
You can hear a special program about Bill and the magic of radio at the links below.
Enjoy!
Radio is Magic Part 1 [http://r20.rs6.net/tn.jsp?f=001M4Z6ZRkTiBMWA-pMdMmhQPUJUVMMys7_l3p8vsxbjtu4mGggZyZI73Qtdn5HsBzl6OWidJqdgKcs8QhDN58oC2AYWcNFjIyeJqJEpBJo_j5IZOVvNjsL0jK_k6eErWyHDgwERVldjAY5ML6VoT4JDBKkF6Icw_l8mot5GkN2na9YsWL44Ty59EXlzyYQ4GZa3BkN4QSF0xQ=&c=WmlMFNRZReARmZ03KzI6Xlu0rYUWBZH9p9iiyvny2Ogq9e2Mt7eB2Q==&ch=yLv2MHXXD47VCVe7VNfTBFIX4WcNW3_xh_s4CDzltbTKEIZ2xlkThA==]
Radio is Magic Part 2 [http://r20.rs6.net/tn.jsp?f=001M4Z6ZRkTiBMWA-pMdMmhQPUJUVMMys7_l3p8vsxbjtu4mGggZyZI73Qtdn5HsBzlifCloFzATHiI9to4q-fpLLkH8bUx2xMrJM17yzBaxr4o5C1Ia34ujGUeUrQO9X5Immwj9gqr4KDnK-Bf0pFMQm0JwjPJK9MBpVA0Hh5XVLLrwFeyTTSA3_Y5Ck5BYV5lcEm01k1kcmQ=&c=WmlMFNRZReARmZ03KzI6Xlu0rYUWBZH9p9iiyvny2Ogq9e2Mt7eB2Q==&ch=yLv2MHXXD47VCVe7VNfTBFIX4WcNW3_xh_s4CDzltbTKEIZ2xlkThA==]
(the part about Bill)
> MRHS Merchandise [http://r20.rs6.net/tn.jsp?f=001M4Z6ZRkTiBMWA-pMdMmhQPUJUVMMys7_l3p8vsxbjtu4mGggZyZI7592JKVvIB27mMFEidBvd-K8PsK2ynmsVkK9aC7wHEn2fTQbudxzW8-eyfokPFAoBamtiYeAEk6iyOnlhAAn00eskDugZENNu3kz2MOTj3f413EICjF9IrPJxEIgPkdYSc-xucI7S8kS&c=WmlMFNRZReARmZ03KzI6Xlu0rYUWBZH9p9iiyvny2Ogq9e2Mt7eB2Q==&ch=yLv2MHXXD47VCVe7VNfTBFIX4WcNW3_xh_s4CDzltbTKEIZ2xlkThA==]
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.
Click on the images to go to the True Believers Store [http://r20.rs6.net/tn.jsp?f=001M4Z6ZRkTiBMWA-pMdMmhQPUJUVMMys7_l3p8vsxbjtu4mGggZyZI7592JKVvIB27mMFEidBvd-K8PsK2ynmsVkK9aC7wHEn2fTQbudxzW8-eyfokPFAoBamtiYeAEk6iyOnlhAAn00eskDugZENNu3kz2MOTj3f413EICjF9IrPJxEIgPkdYSc-xucI7S8kS&c=WmlMFNRZReARmZ03KzI6Xlu0rYUWBZH9p9iiyvny2Ogq9e2Mt7eB2Q==&ch=yLv2MHXXD47VCVe7VNfTBFIX4WcNW3_xh_s4CDzltbTKEIZ2xlkThA==]
Just click on the images above to go to the MRHS True Believers store [http://r20.rs6.net/tn.jsp?f=001M4Z6ZRkTiBMWA-pMdMmhQPUJUVMMys7_l3p8vsxbjtu4mGggZyZI7592JKVvIB27mMFEidBvd-K8PsK2ynmsVkK9aC7wHEn2fTQbudxzW8-eyfokPFAoBamtiYeAEk6iyOnlhAAn00eskDugZENNu3kz2MOTj3f413EICjF9IrPJxEIgPkdYSc-xucI7S8kS&c=WmlMFNRZReARmZ03KzI6Xlu0rYUWBZH9p9iiyvny2Ogq9e2Mt7eB2Q==&ch=yLv2MHXXD47VCVe7VNfTBFIX4WcNW3_xh_s4CDzltbTKEIZ2xlkThA==]
and browse our offerings. Thanks!
Whew! Okay, that's it for this issue. Thanks for reading. We very much look forward
to hearing you on the air or seeing you in person on Night of Nights. Until then
we wish you the best of luck and fair winds & following seas.
73,
MRHS
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