Page 1

Christmas Party - Vintage Radio Station - Interference on the HF Bands HF Propagation programs & more ...

December - January


Worthing & District Amateur Radio Club Established 1948

http://www.wadarc.org.uk - email info@wadarc.org.uk President: G8FMJ John Slater

Life Vice President: G8MSQ Peter Robinson

WADARC meet every Wednesday at 8pm in the Lancing Parish Hall, South Street, Lancing BN15 8AJ. All that have an interest in radio communications and associate subjects, whether a licensed amateur or not, are invited. WADARC can also arrange training for people to undertake the Radio Amateur Foundation, Intermediate & Advanced licenses. WADARC Committee 2012 - 2013 Kelvan! ! Andy! ! Sandra ! ! John ! ! Jonathan! Peter! ! Norman! ! Rod! !

M0KEL! ! M6RFE! ! G0KAG! ! G8FMJ! ! G1EXG! ! G4LKW! ! M6NWJ! ! M0RDV! !

Chairman! ! Secretary! ! Treasurer! ! President! ! Ordinary Member!! Ordinary Member!! Ordinary Member!! Secretary! !

WADARC Ex Officio 2012 - 2013 John ! Peter! Chris ! Graham Phil! Martin !

! ! ! ! ! !

G8FMJ! ! G8MSQ! ! G3NDJ! ! G4FNL! ! G4UDU! ! M0ADY ! !

Publicity!! ! Membership Manager! Awards Manager! ! Contest Manager!! Ragchew Editor! ! Club Webmaster! !

WADARC Foundation, Intermediate & Advanced Courses & Licensing Kelvan! !

M0KEL! !

Training Officer! !

WADARC Club Nets - all times are local 09:00!

Sunday! !

145.550MHz (Pre RSGB News on 145.525MHz)

19:30!

Monday!!

145.425MHz

11:00!

Thursday!

7.110MHz


Contents From the Editor's Keyboard!

1

Chairman’s Chatter!

1

Presidential Ponderings!

1

Secretary's Report!

2

Christmas Dinner!

3

WADARC Christmas Radio!

5

FLDIGI!

6

Construction of a Vintage Radio station - Part 3!

6

M F C A!

9

Noise - and how to remove it!

10

Solar Forecast - Sun's Peak Activity To Hit Century Low!

15

Forthcoming DX Dates!

17

WADARC Club Programme 2013!

18

You should have paid your membership fee for 2012/2013 Those who have not paid will be removed from the RAGCHEW Distribution and the email list Please ensure you have paid WADARC needs your membership


From the Editor's Keyboard There has been a bit of a delay getting this issue out, usual problems with work etc. I must not complain as it is good to be busy. We have some new members on the committee and the events calendar is in good shape with interesting meetings. If you have any ideas for a subject you would like to see on the list please let a member of the committee know. We have a good range of skills amongst the membership with many interests in different aspects of amateur radio and I am sure we can get someone with some specialist knowledge to provide a talk at a meeting. We have the final instalment of Peter G3LDO’s article on his vintage radio station in this issue, he is always busy with different projects so it will be interesting to know what is next. Phil G4UDU

Chairman’s Chatter Happy New year to you all and thank you for your messages of sympathy for the death of my father, Arthur G8EAS. Also thank you for all the messages congratulating me on my engagement to Barbara. I am running an Intermediate course, followed by a Foundation course and I will also be starting an Advanced course at the same time. Those interested or anyone you know who is, please let me know. Regarding talks: if you know someone who would like to give a talk or if you would like to give one, please let John or me know. The D-Star repeater is off air at present because it is being re-located to the Town Hall. As soon as it is done, I will put on the e-mail reflector. Kelvan Gale M0KEL

Presidential Ponderings Another year has past and we are all looking forward to 2013. From the club's perspective, I think we have had another good year. Regrettably, we have lost a few members BUT we have also gained some, which I think is a credit to the club and the facilities we offer. We have put on several very successful special event stations, due to the efforts of the usual few, they know who they are, we also put in a very creditable effort in SSB field day, again, a real team effort was required for this one.

Page 1


The weekly club evenings seem to have gained in popularity and the round-table format is a real winner, good to see so many regulars each week. We have had some superb talks, not only from guest speakers but also from our own members and this will continue next year, we already have several offers from within the club. I hope you have enjoyed the varied talks and some of the surprise evenings. My workload still makes it difficult for me to have as much spare time as I would like, so if anyone would like to have a go at running the club programme, PLEASE let me know. The annual club Christmas party was one of the best attended for some years and hopefully one of the most enjoyable, lets see if we can increase the numbers for next year. My thanks to the committee members, past and present for their efforts and to Phil for producing the superb electronic version of this Ragchew, long may it continue. Best wishes for 2013 John-G8FMJ

Secretary's Report The club AGM took place at Lancing Parish Hall on 17th October 2012 Votes were taken to elect a new committee Kelvan M0KEL was re-elected as Chairman. John G8FMJ was re-elected as club president. Sandra G0KAG was re-elected as club treasurer with myself (Andy M6RFE) being elected as club secretary. With some changes amongst committee members the new committee for the following year is: President John Slater G8FMJ Chairman Kelvan Gale M0KEL Treasurer Sandra Grindley G0KAG Secretary Andrew Braeman M6RFE Pete Head G4LKW (Ordinary member) Rod Vincent M0RDV (Ordinary member) Jonathan Hare G1EXG (Ordinary member) Norman Jacobs M6NWJ (Ordinary member) Phil Godbold G4UDU offered to remain as the club magazine editor. Meeting frequency was discussed and a vote taken, resulting in the decision to retain the weekly meeting format in the new year.

Page 2


Discussion was held regarding the club frequency for the year with a decision being taken that it will be 17metres Committee meetings will continue to be held bi-monthly and the next meeting has been scheduled. Any matters members may wish to be raised at the committee meetings can be discussed in advance with a committee member. Andy M6RFE

WADARC Christmas Party The annual WADARC Christmas dinner took place on the 12th December and a good number this year, with 48 attending. Many thanks to Joy Slater G1UGB for arranging the excellent catering, a difficult task when the number you need to provide for is not known until the evening of the event! Report from Chris G3NDJ (Awards Manager) on awards made at the club Christmas dinner is as follows:There were a large number of well-made entries for the constructors competition and this year we have two winners, Peter G3LDO and Andrew M6OJC For his involvement in club activities, the club championship is awarded to Chris G3UFS The G8HY award for his help on club events goes to Rod Vincent M0RDV The Chairman's award is to Peter Robinson G8MSQ This year the HF award was for the most countries worked on the 10 meter band. There were only two logs submitted, one from Ted G3EUE, who worked one hundred and sixteen countries and the second was from Chris G3NDJ, who worked one hundred and twenty six countries, therefore Chris is the winner in 2012. The band for this year through to September 2013 is 17 metres and should prove to be good for all the club members to take part and certainly 10 watts on this band is very effective, small antennas can work very well and the band is exceptionally busy at weekends The G4FPM award for best lecture throughout the year is given to Jerry M3ORP

Page 3


The annual two meter DF hunt was won by our President John G8FMJ

Page 4


WADARC Christmas Radio The two schedules - 80m on Christmas Eve at 21:30 and 2m on Christmas Day at 10:00. I ran the 80m where we had 12 stations check in, the band was a bit noisy and did not favour inter-UK operation. The 2m session was run jointly by John G8FMJ and Chris G3NDJ. There were 41 stations who checked in, I think John was hopeful for a few more but that was good for the morning. If we could only get all of the club members and others around on the HF bands! We will try again next year

Page 5


FLDIGI This excellent piece of software is used by a number of members to work the Data Modes. There was a mention in QST, with the writer awarded for his work in creating FLDGI. Honouring the Creator of FLDIGI At the 2012 ARRL Southeastern Division Convention in Huntsville on 18th August, Southeastern Division Director Greg Sarratt W4OZK presented a Special Technical Service Award to Davin H.Freese Jr W1HKJ, of Tony Alabama. For those who do not recognise the callsign, David is the inventor of the Fast Light Digital Modern Application, better known as FLDIGI. It is one of the most popular free multi-mode digital communication software packages available to amateurs today. David received the award in appreciation for his service to the amateur community in general and for his assistance to ARRL station W1AW, which uses FLDIGI for it’s digital bulletin transmissions.

Construction of a Vintage Radio station - Part 3 In the last two Ragchews I described a project where a vintage radio station, 1939 era, was constructed to provide a demonstration working station on the 7, 10 and 14MHz amateur radio frequency bands using CW. The receiver section of the project, a National HRO receiver in a restored original condition, was described. This part described my experience operating this rig under modern HF conditions. As described in the last Ragchew, the early start up of this transmitter went relatively smoothly. The main problem was VFO stability, with unacceptable jumps in frequency. I had chosen what looked like a good quality valve base from the original transmitter to build the VFO. Unfortunately, it appeared that some valve pins made inadequate connections through the valve base. Cleaning and tensioning the valve pins improved things. A partial rebuild of the VFO circuit rebuild was also required. The design would have benefited from an extra stage of VFO buffering but this was not possible because of space restrictions. The previous owner of the HRO receiver had replaced all the larger value fixed capacitors and the receiver worked quite well but it did develop some faults after a short while. The 42 type audio output valve failed. I didn’t have a replacement so I made an IO/UX base adapter and used a 6D6 octal-based valve. The 6B7 detector valve also failed, becoming very microphonic and intermittent. I was lucky to find a replacement from Amberley museum. The only other fault, a high value resistor in AGC line, became open circuit. I didn’t have the correct

Page 6


value replacement at the time and used a lower value. This had a fortuitous outcome. The only mode used with this vintage station is CW. The HRO handbook advises that the AVC switch be turned off, the audio gain control turned up and signal level adjusted using the RF gain control when using this mode. On the ham bands signals come in over a large range of signal strengths. When listening to a weak DX station, with the gain controls set for CW as described above, any high powered short skip station close to the frequency nearly blew my head off when I was using headphones, Using a lower value AGC resistor resulted in a less active AGC action. This in turn allowed the AGC to be used when in the CW mode and prevented excessive audio output. One of the most noticeable characteristics of old radio equipment using valves can be the warm up frequency drift. My HRO receiver has a warm up drift from switch-on of over 50Hz per minute, which settled down to 18Hz per minute after about 30 minutes (on 14MHz). The local oscillator on this early receiver does not have a stabilised supply and the frequency tended to wander a bit even when warmed up. I found I could live with this if I used a plug-in coil with the amateur band spread facility selected. Later editions of the HRO provided a stabilised supply for the local oscillator. The new VFO in the transmitter had a frequency drift of around 50Hz in the same period but settled down to 2Hz when warmed up (after some experimenting with negative coefficient capacitors). The transmitter has to be tuned to the desired incoming signal to make a contact. I also wanted to monitor the transmitter during the transmission and to do this the RF gain had to be backed off (muted). I achieved this automatically by fitting a receiver RF gain control in transmitter, which was switched in by a spare set of contacts on the transmit/receive relay. A ‘single-signal’ [see Note] capability of a receiver for CW is an important characteristic. The HRO has this facility, which says a lot for the advanced design of the time. The single crystal filter has a deep notch within its characteristic, which can be placed over the image signal as shown in Fig 1. Initially this took a while to get used to because placing the image signal in the notch required the correct setting of the crystal phasing, IF selectivity and the BFO frequency. It is very important that the transmitter is netted to the correct signal and not the image. More than once I had responded to a station and not received a reply because the transmitter was tuned to the image signal. A calibrated absorption wavemeter was an essential item of test equipment in the early days. This instrument was necessary to ensure the multiplier(s) were tuned to the correct harmonic when the transmitter was first tuned up. A chart could then be made once the settings have been established.

Page 7


The transmitter had a characteristic chirp when the buffer amplifier was tuned to VFO frequency. The effect was reduced by setting the tuning control just on the LF side of resonance. This could be done without any reduction in transmitter output. The first QSOs were made using a wire antenna some 20ft high and 80ft long, resonated against ground using a MFJ-989c ATU. I had a couple of older ATUs but the MFJ had both a power/SWR meter and a dummy load, useful for setting up the transmitter. Once I had gained confidence, I started looking for DX on 14MHz using my threeband quad. The HRO proved to be sensitive enough and real DX could be worked provided the band was not too crowded. Strong signals in the skirts of the selectivity curve (Fig 1) proved difficult to manage. Using the receiver during weekend contests was a bit like driving a vintage car on the M1. This problem was predicted and was the reason why the 10MHz band, with its contest free zone, was included in the transmitter design. At the time of writing I have worked 68 countries, mostly on 14MHz.

Fig. 1: The frequency response of the HRO receiver with and without crystal filtering. It also illustrates the suppression of the image signal with the crystal notch characteristic

Page 8


NOTE: A CW signal from the output of the IF section of the receiver, say at 456kHz, requires a beat frequency oscillator (BFO) signal at 455kHz to produce a 1kHz signal at the detector. However, a signal at 454kHz will also produce a 1kHz signal at the detector, which means that an incoming signal on the receiver dial can be heard in two places on the receiver dial, 2kHz apart. This unwanted ‘image’ signal is easily filtered out with modern receivers using narrow band-pass filters with steep skirt characteristics. In early receivers this was more difficult because of the filter passband frequency characteristics used at the time.

MFCA Following on from the last Ragchew and an email from Ted G3EUE, some information on the Austrian Naval Station we had a QSO with, from the GB4SLB Selsey Lifeboat station. OE6XMF is the club call. Sepp OE6ESG was the operator we had this QSO with. M arine F unc C lub A ustria Exactly 100 years ago, from the 8th to 22nd December 1898 resulted in the contact between Imperial and Royal Navy, the first experiments with radio telegraphy in the Adriatic sea. The MARCONI English radio stations were in use, the radio communications took place between the ships SMS Budapest, SMS Lussin and the Fort Musil. This was preceded by radio links in place in Vienna. In an official report it was mentioned that the current “state of the art” experiments with MARCONI radio equipment provided a satisfactory result The MFCA was founded in April 1997 and is a member of the Radio League (ÖVSV). We foster the preservation and promotion of Amateurfunkwsens with all amateur radio operators in the world, as well as connection and friendship with union shared goals. MFCA The Marine Radio Club Austria, has a major club station, with the international amateur radio callsign OE6XMF. Our MFCA currently has 81 members. We are very pleased that we have achieved in the short time since our founding this high level of membership. We are radio amateurs and shortwave listeners (SWL) and belong to the majority of the Austrian Radio League (ÖVSV). The members from Germany are included in the German Amateur Radio Club (DARC). Austria has a very rich maritime history, this dates back many years. Under the Austrian flag, Austrian shipping companies are currently operating more than 40 merchant ships on the world's oceans. Pete M6PAP

Page 9


Noise - and how to remove it The problem of noise on our HF receiving antennas has become a lot worse in recent years. The increase of portable electronic devices and general equipment, especially those powered with chargers operating on switch mode power supply plug in wall units, all raise the background noise level to a level where incoming HF signals are now often very difficult to hear These levels differ depending on whether you live in the centre of a town or in a more rural location. I live on the outskirts of the village and I know I do not have the same sort of noise problem as some others who have to cope with a town centre location

The diagram shows the noise levels that are typically experienced, and from this you can see that the difference between that of a town and a quiete location is quite significant. The aim is to hear the atmospheric noise level, which is the point at which signals can actually be heard, any extra noise above this removes the ability to hear the weaker DX stations

Page 10


There are primarily three different ways of tackling the noise levels and trying to find a way to reduce it First there is an add-on audio filter. This plugs into the headphone or the extension speaker socket and is limited to reducing the overall noise level to make it more acceptable and, therefore, to allow you to hear stations from within that noise envelope. This is done either by an “analog device�, which limits the receiver audio bandwidths and additionally adds manual or automatic notches to take out specific frequencies with carriers .The other option is a DSP device this works by using a specially designed algorithm to work on recognising the difference between interference this being pulse or continuous tones and speech as a variation of levels and frequencies. Therefore, anything it sees of this type it takes to be audio and everything else it tries to reject. This can provide sometimes quite amazing results on simple audio but it does suffer with problems on CW because it sees the single frequency tones as interference and of course it would do exactly the same with the data modes. I would consider this type of filter is possibly the least effective in providing a solution. The next type is the filtering available inside of our receiver, this is either IF filtering which basically allows you to restrict the bandwidth by means of the internal crystal filters or now on new transceivers can be DSP. This digital system can reduce the bandwidth received in a more advanced process as either upper or lower frequency adjustment in addition to shifting the complete signal and has quite dramatic results in providing a more acceptable signal, plus there are also algorithms that work to recognise specific audio and CW signals and pull them out from the noise. There is also another option where the DSP in a transceiver works only in the audio stages. This is exactly the same as the external add on filter described above with the same limitations The third type is a device that actually goes in the antenna input to receiver The unit of this type I am using is the JPS ANC-4, there is a comparable unit made by MFJ that operates in the same way. The station antenna picks up noise, both locally and remotely generated, as well as the desired signals and passes everything directly to the receiver. This reduces the number of signals actually heard to those stronger than the received base noise level, so if we could just take away the noise component and leave the rest this would be the perfect answer, allowing the filters and DSP in the radio to work at their best.

Page 11


Looking at the block diagram and signal flow, this is how it works. The signal from the main antenna is combined with a signal from the noise antenna. The main antenna signal contains desired information as well as noise. The noise antenna signal, which contains mostly the local noise, is amplified and passed through a

Page 12


phase shift network so that its phase can be adjusted to 180 degrees compared to the main antenna signal. On the front panel there are the following controls, “noise” “phase” and “noise gain”. You adjust the noise antenna phase and gain to just equal the noise signal level picked up by the main antenna, but shifted 180 degrees in phase. Two phase shift networks (phase range A & B) are incorporated to give maximum flexibility and cover most local noise situations. There is a switch (frequency range) to optimise the noise cancellation network for operation at frequencies above 20MHz. The “hi” range on this switch is also usable at low frequencies and provides an additional phase shift network which may be required if a satisfactory phase null cannot be obtained with either phase A & B switch positions. The combined signals, with the local noise cancelled, are passed on to the receiver via the radio connector on the rear panel. This system works on all of the HF bands with good results up to 6m. The antenna you use for the noise pickup has to be optimised to frequencies and/or bands that the problem occurs on. So now we have Wanted Signal + Atmospheric Noise + Local Noise - Local Noise = Wanted Signal + Atmospheric Noise When properly adjusted, typically 30 dB reduction of the locally generated noise is possible, leaving only the normal atmospheric noise level existing on the band, signals that were masked by the local noise can now be heard. This type of device is certainly not the easiest to set up and use, but with some careful adjustment the results are amazing. Here are some pictures taken from the spectrum scope on my K3 that will show the effect. The test I was doing over the last few weeks was on a problem with 160m and to a lesser degree on 80m. I am still trying to find the source of this. It is only on at night and continues all the way through to about eight in the morning, a horrible buzzing noise that varies in level, sometimes reaching S9, this can be almost completely removed with a bit of fine tuning. I have found one of the separate 160m loop receiving antennas I have here works to give me the best option to provide a signal to null the noise.

Page 13


The signal with the noise - notice the lines on the waterfall display that show the pulsating buzzing noise

The signal with the noise removed - the waterfall display now shows the noise has almost gone plus the spectrum signal base line drops

Page 14


This type of filtering is without doubt the best and if you can spend the time to make it work correctly, it will give amazing results in some of the most horrible noise conditions. Phil G4UDU

Solar Forecast - Sun's Peak Activity To Hit Century Low The current solar cycle 24 is heading towards a 100 year low. Sunspot numbers should peak around July 2013 - then it’s an eleven year wait until the next peak. There is some slightly better news, the solar cycle usually rises quickly to the peak and then declines slowly to the solar minimum, so we have a bit more time for this strange cycle to maybe pull a few surprises and with a bit of luck give us some better radio conditions.The sunspot peak should give us the 10m band wide open to all of the world during the day plus good reliable openings 6m - but this time, I do not think it’s going to happen - 2024 seems a long time away!

Page 15


So we know the numbers are not good - but what can be done with the data? The answer is to try one of the DX Propagation forecast programs. Here are details of two free ones. VOA Prop

Julian Moss G4ILO programmed an excellent easy-to-use VOACAP user-interface It shows you in real-time what is possible in terms of propagation and it might be your entry-ticket to start using VOACAP. Visit G4ILO's Shack and download VOAProp for free! HamCAP with DX Atlas

Page 16


Written and distributed for free by Alex Shovkoplya VE3NEA, HamCAP combines the full power of real-time DX-spotting and VOACAP HF propagation predictions with DX Atlas, an excellent topographic DXCC atlas.

Forthcoming DX Dates Click on the links to go to the relevant websites C6AVA Bahamas 2013 new - QSL via N6AWD NA-048 Expedition 11 - 14 January, 2013 IG9Y - Lampedusa Island 2013  new - The Lampedusa 2013 DXpedition is composed of an international team from 6 countries. We will be on the air October l 17 thru October 30, 2013 running 4 stations on 160M through 6M (SSB/CW/ RTTY). V31ME Belize  new - Date: 3-17 Jan 2013 QSL via DJ4EL 5W0M Samoa 2013 - DXpedition to Samoa 5W0M, April 4th to 18th 2013 a German team will activate Samoa, IOTA OC-097 5X8C - Uganda 5X8C DXpedition 2013 A3EAQ - Jacek, SP5EAQ will be QRV as A3EAQ from Tongatapu in the Kingdom of Tonga from the 26th March to the 16th April 2013 H44G H40T - Solomon Islands H44G/ Temotu Islands H40T - March 2013 by DL7DF H44KW - Jim, G3RTE and I will be QRV as H44KW from Honiara, Guadalcanal in the Solomon Islands from the 18th to the 28th February 2013. KH8 N6MW Amaerican Samoa - March 2013 DXpedition to American Samoa TX5K Clipperton Isl. - 2013 DXpedition to Clipperton Island TX5K XT1T Burkina Faso - Feb - Mar 2013 XT1T DXpedition with Log Online BY IDT

Page 17


WADARC Club Programme 2013 JANUARY 2nd No Meeting 6th Monthly Breakfast Meeting at the Goring Café 9am 9th Talk by Phil G4UDU - Portable Magnetic Loops (FBIACB) 13th AFS contest CW 16th Discussion Evening 19th AFS contest SSB 23rd Talk by Graham G4FNL - Electronic Logbooks 30th GX3WOR On-the-Air evening FEBRUARY 3rd Monthly Breakfast Meeting at the Goring Café 9am 6th Discussion Evening 6th 80mtr CC-SSB contest 13th Talk by Barrie Turner, Shoreham Coastwatch 20th Talk by Graham G4FNL - Internet Applications in Amateur Radio 23rd 80mtr CC-CW contest 27th GX3WOR On-the-Air evening MARCH 3rd Monthly Breakfast Meeting at the Goring Café 9am 6th Surplus equipment sale 13th Discussion Evening 13th 80mtr CC-CW contest 20th TBC 21st 80mtr CC-SSB contest 27th GX3WOR On-the-Air evening APRIL 1st 80mtr CC-CW contest 3rd Talk by Peter M6PBK, Alister G3ZBU and Merv 2E0WVE - Steiff in Space 7th Monthly Breakfast Meeting at the Goring Café 9am 10th Discussion Evening 10th 80mtr CC-SSB contest 17th Talk by Mike G3LHZ - A small high power, wide band Untuned loop monopole 24th GX3WOR On-the-Air evening

Page 18


Items for Sale If you have any equipment you would like listed here, please send me the details via email.

Page 19

Ragchew Dec/Jan  

Ragchew for December & January

Read more
Read more
Similar to
Popular now
Just for you