International Marconi Day at Sandford Mill

The extensive collection of historic radio exhibits at the Sandford Mill Museum in Chelmsford will be open to the public on Saturday 25 April 2015 

Chelmsford's former waterworks at Sandford Mill is primarily a museum collections store and science education resource however it is open to the public for special events during the year.

Sandford Mill has featured in TV programmes such Great British Railway Journeys and The Wave Messengers. The building houses an extensive radio collection, with some equipment dating back to the 1890’s. There is a series of five ship’s radio room displays representing different decades including some very rare Marconi equipment from ships contemporary with the Titanic.

On Saturday 25 April 2015 from 10am to 5pm the collection will be open to the general public to celebrate the birthday of Guglielmo Marconi who was born on that date in 1874. 

The Chelmsford Amateur Radio Society (CARS) will be operating a demonstration station, call sign GX0MWT, in the historic Marconi 2MT Writtle broadcast hut which is now housed inside the museum.

On the first floor Colin Page, G0TRM and his team will be demonstrating the impressive Mechanical Morse and Morse Key display with the opportunity for the youngsters to try their hand at sending Morse. The Morse punched paper tape sending and decoding process always proves to be a big hit with potential junior CW operators.

During the day there will be several presentations in the Barn on the museum site. At 2:15 pm Dr Elizabeth Bruton, well known for her presentations at the RSGB Convention, will give a talk on Marconi. This includes details about the vital wartime contribution made by the Marconi Company and Marconi Company Engineers and staff employed by the British military during World War One. It will include a local element: the establishment of a signals interception station located in the Hall Street works in Chelmsford. 

CARS Vice President John Bowen, G8DET will be giving three presentations titled “Saving Lives at Sea – up to and including the RMS Lusitania” at 11am, 1pm and 3.30pm.

Sandford Mill is run with the help of the Friends of Chelmsford Museums and other ex-industry volunteers. It relies on the support of several voluntary bodies including Chelmsford Amateur Radio Society, the Radio Officers Association, the Marconi Veterans Association and the Susan Trust. Susan is the last wooden Chelmer Barge and is undergoing restoration (financed by funds devotedly raised by the Susan Trust), before returning to her moorings at Sandford Mill.

The Museum is located in Sandford Mill Road, Chelmsford, Essex, CM2 6NY, admittance and parking are free.

Chelmsford Amateur Radio Society - Sandford Mill - http://www.g0mwt.org.uk/sandfordmill/ 

Chelmsford City Council - http://www.chelmsford.gov.uk/sandfordmill

Amateurs and Vehicular Radars Can Play Nicely Together

In comments filed on 6 April 2015 in response to a February FCC Notice of Proposed Rulemaking and Reconsideration Order (NPRM&RO) in ET Docket 15-26, the ARRL has told the Commission that it should make no change in the Amateur Radio allocation at 76-81 GHz and impose no additional regulatory constraints on Amateur or Amateur-Satellite uses of the band.

The League said the FCC should proceed with authorizing short-range radar (SRR) systems for automotive applications in the band under Part 15 rules, and that such applications are compatible with amateur operations in the band.

NPRM&RO (PDF format) - https://apps.fcc.gov/edocs_public/attachmatch/FCC-15-16A1.pdf

In its NPRM&RO, the FCC solicited comment on issues involving expanded use of various radar applications in the 76-81 GHz band, which Amateur Radio shares with other services. The band 77.5-78 GHz is allocated to the Amateur and Amateur Satellite services on a primary basis, and to the Radio Astronomy and Space Research services on a secondary basis. The NPRM&RO was in response to a 2012 Petition for Rulemaking (RM-11666) by Robert Bosch LLC and to two petitions for reconsideration of a 2012 Report and Order (R&O) addressing vehicular radar systems in the 76-77 GHz band. ET 15-26 incorporated earlier proceedings.

The R&O can be found on the web -  http://www.fcc.gov/document/toyotaera-76-77-ghz-band .

In its comments, the ARRL suggested that the FCC overreached in proposing unjustifiable changes at 77-81 GHz on its own initiative.

"There is not, anywhere in the four corners of the Bosch Petition for Rule Making or in any comments that have been filed thus far in response to RM-11666, any suggestion that there is any incompatibility between Amateur Radio operation and automotive radars," the ARRL said. "Quite the contrary." The League said a credible, current ITU study has "definitively established" compatibility between short-range automotive radars and Amateur Radio.

The ARRL said Bosch's filing of its Petition followed "extensive discussions and technical evaluations between ARRL and Bosch" that making spectrum at 77-81 GHz available for automotive radars "would have no significant impact on the Amateur Radio Service." Bosch, the League pointed out, "did not propose a domestic spectrum allocation for vehicular radar devices and systems," just modification of the FCC Part 15 rules to permit vehicular radars at 78-81 GHz on the same basis that these radars now operate in the US at 76-77 GHz - on a non-allocated, non-interference basis.

The ARRL said that no changes are necessary in the Amateur Radio domestic primary allocation at 77.5-78 GHz or in the secondary amateur allocation at 77-77.5 GHz or 78-81 GHz to accommodate automotive radar systems at 77-81 GHz. "Nor are any additional Part 97 rules necessary to accommodate compatible sharing of that band between radio amateurs and automotive radar systems," the League added. "Indeed, that is the position of the United States in anticipation of consideration of WRC-15 agenda item 1.18 later this year."

The League characterized as "both premature and poor spectrum management" the FCC's proposal to unilaterally permit unspecified fixed radar systems throughout the 76-81 GHz band "without the benefit of any completed, definitive studies relative to the compatibility of fixed radar systems with automotive radar, radio-astronomy and/or Amateur Radio in this band."

Any consideration of fixed radars at 77-81 GHz, the League said, "should await the completion of conclusive, refereed compatibility studies that credibly establish compatibility with incumbent services."

The ARRL said should there be any "unjustified displacement" of the Amateur or Amateur-Satellite services from any portion of the 76-81 GHz band, the FCC should allocate "equivalent spectrum" for those services. As possibilities, the League suggested the bands 75.5-76 GHz and 81-81.5 GHz.

The deadline for reply comments - ie, comments on filed comments - in this proceeding is 20 April 2015. The ARRL plans to file reply comments.

HB9AW Beacon Report

The amateur radio club of Sursee, HB9AW launched a 60 metre beacon project during June 2014. The president of the Sursee club, Kari Künzli HB9DSE has kindly reported the current status of this project.

Kari said that the motive of the project was to investigate 60 metre propagation within Switzerland and Europe. The 60m band is not a current band for radio amateurs in Switzerland but it looks like it could become an amateur band at the next WRC conference. Given the possibility of getting access to the 60m band in Switzerland and other European countries knowing what to expect from propagation is of great interest.

Most assume that the propagation will be somewhere between what we presently achieve on the 80m and 40m bands, however this is only an assumption and a quantifiable investigation would be of great value.

The HB9AW beacon is a cw transmitter which sends its call sign hb9aw at a power of 10W followed by 5 dashes. Each dash is sent for 5s. The first dash is sent at 10W, the second at 5W, then at 1W, at 100mW and the fifth dash at 10mW. The frequency is 5291kHz, occupying a narrow bandwidth of about 100Hz.

So far just over 2000 reports have been received from all over Europe, and the 60m beacon has also been heard in America.

When sending in a report one has to state how many dashes have been heard - this indicates at what power level the beacon was no longer audible.

While these reports are appreciated they can be affected by many parameters including receiver and antenna performance. Some stations have an antenna optimised and resonant on the 60m band while others simply use the antennas that they have which could be completely wrong for 60m.

To obtain more accurate data a standard beacon receiving station is being built, which should provide more reliable signal reception data. The standardised beacon receiving station consists of a receiving antenna, a receiver and a measurement device. The antenna is a loop antenna of approximately 1m diameter, resonant at 5291kHz. The connected receiver has a bandwidth of 100Hz which delivers a signal to the measurement device. The measurement device records signal data in dBm five times per second, which means each dash is measured 5 times per second and the unit sends the values in dBm to a central server where the data is stored and analysed. The intent is to place 50 of these receiving stations in Switzerland and across Europe so that the central system receives simultaneous signal reports throughout Europe for the analysis.

The standardised receiving station is being built by a team within the club. One part of the team deals with the development of the antenna, another part with the receiver and the third part works on the measurement unit. The measurement unit will be a Raspberry Pi. It's development is already at an advanced stage. The receiver development group is led by Hans Zahnd HB9CBU, who is well known for his digital ADAT SDR receiver.

Three prototype systems have already been built.

The team plan to produce fifty receiving stations and would like to sell them to radio amateurs across Europe. The production run has been set at 50 units to meet a reasonable price level.

HB9AW - http://www.hb9aw.ch