.

Ο λόγος στασίμων 1:1 ενός κεραιοσυστήματος, δεν συνεπάγεται τον 1:1 λόγο μεταφοράς ισχύος, προς την κεραία!

Saturday, 18 February 2017

Attn all conspiracy theory enthusiasts


Regarding this February 2017 campaign, HAARP will be operating from 19 to 22 February.
Specifically, experiments will begin daily sometime after 1800 hours 2/19 UTC. My experiments will be the last each day (local Alaska time) and are scheduled to start at 0330 hours on 2/20, 2/21, and 2/23 UTC; and at 0430 hours on 2/22.
Experiment times and frequencies are subject to change for various reasons, particularly in response to ionospheric conditions shortly before each experiment.
I will do my best to update https://twitter.com/ctfallen in real time.
Operations are very active times and I will be monitoring conditions and equipment so generally speaking, for my artificial aurora experiments, your best bet is to search around 2.7 MHz +/- 100 kHz given current conditions.
For the Luxembourg effect experiments, I will try to keep the two frequencies separated by about 1 MHz, which means that they will occur earlier in my experiment window rather than later, when the ionosphere is more dense.

 Chris Fallen (KL3WX), Is assistant research professor in the University of Alaska Fairbanks Geophysical – Space Physics group , who shares the following update in reference to upcoming HAARP activities

Προσοχή, ανεμοψεκασμένοι, συννεφοψεκασμένοι και απλοί ψεκασμένοι!
Το HAARP θα τεθεί σε λειτουργία το τετραήμερο 19/22 Φεβρουαρίου. Αναμένονται σεισμοί-λιμοί-καταποντισμοί!
Για τους υπόλοιπος εμάς τους κοινούς θνητούς με τεχνολογικές ανησυχίες, το σύμπλεγμα HAARP θα κάνει δοκιμές από τις 19 έως και 22 Φεβρουαρίου οπότε καλό είναι να έχουμε τον νουν μας στους δέκτες μας και στην διάδοση αν τύχει και αλλάξει κάτι από το στάνταρ χάλια των τελευταίων μηνών! Ο συνάδελφος(ραδιοερασιτέχνης) Καθηγητής Chris Fallen θα είναι στο twitter να μας ενημερώνει!

Sunday, 12 February 2017

QRP Q&A


What is, QRP?
QRP is a term adopted from the international RQS signals meaning to reduce
power. Hams have taken this term and its meaning to be low power.
Generally, ORP is 5 watts or less from the transmitter, regardless of the input
power to the transmitter. If you hear someone on 40 meters calling CQ QRP,
he (or she) is calling for a low power station. More than likely, they will be using low power, too.

What is, QRPp?
QRPp is the older term for RF power of 1 watt or less. That extra small "p'
meant really low, low power, generally under 1 watt. That term has been replaced by the term "miIliwatting." While it may be hard to believe, you really can work around the world with an output power of 50 milliwatts! There have been many hams working DXCC with only 100 milliwatts to the antenna. It is hard to do, but not impossible.

What are the most popular QRP bands?
There really is no one band more popular than the others. You'll find QRP
operation everywhere from DC to Light. But, some consider the 40 meter
band around 7.040 MHz to be QRP Central. You can also find some action
on 7.035 MHz and 7.060 MHz. In the winter time, when summer QRN is
down, 80 meters is very popular during long cold nights. There is QRP activity
on 160 meters, too.
The 30 meter band is a QRPer's delight! Try 10.106 and up for low power
signals. Then, let's not forget about the 20 meter band either. This is by far
the most popular ham band when it comes to working DX. Low power operation used to be located around 14.060 MHz, but alas, other forms of digital signals have been moving down, overtaking the QRP-calling frequency.
Check the entire band for QRP operators-they're everywhere on 20. You
can find QRP signals on 17, 15, and 10 meters, too.

I'm not into cw, Can I still operate QRP?
CW is by far the most popular mode of QRP operation. It's partly because
CW transmitters are easier to build than SSB rigs. With CW, you get more
bang for the watt, too. But QRP is not only CW, it's any rnode you want to use, including FM or SSTV. QRP means low power-not CW only. 

Do I need to change rigs or equipment to operate QRP?
Of course not! Most of today's rigs can be easily turned down from a front panel control. You'll end up with low transmitter efficiency, but you won't have
to spend a penny.


How about antennas? All I have is a simple dipole.
No matter what power level you use in amateur radio, the better the antenna.
the better your signal will be. Use a good grade of feed-line and get the
antenna as high as possible.


I enjoy a good contest now and then. How can I compete with other stations if I run only 2 watts?
Most of the major contests, such as the CQ World Wide DX contest,
Sweepstakes, and even Field Day, have special low power sections. You only
compete against others within the same power class. You don't have to worry
about the guy running a kW because you are not in the same class!


I know many QRPers like to build their own gear. I'm not much of
builder. Can I purchase a commercial QRP transceiver?

It's too bad you don't like to build your own gear. You're missing out on a
lot of fun. But yes, you can purchase a commercial QRP transceiver.

There are many other mono-band rigs, such as the MFJ, Youkits, Hendricks, etc available. 

 Almost all of the circuits I've seen in the last decades have been 
solid-state transmitters. How about us guys with boxes full of tubes?
It is the 21 Century and today's technology is solid-state and microprocessors.
But, if you want. you can still use a vacuum tube in a QRP transmitter. The
best place to look for a circuit is in an old copy of the ARRL Handbook. Begin
looking with the early '70s and work your way back to the '50s. Parts for
those circuits may be next to impossible to locate, unless you have a really
big junk box!!!
Can I operate PSK31 or JT65?
Yup! Sure can. Again, QRP simply means low power. Any mode of communications is suitable for QRP, with the exception of moon-bounce! I've had some great QSO's using PSK31 with less than 4 watts PEP.


Are there any QRP clubs to join?
Yes! As a matter of fact I'm member of the British G-QRP which is based in United Kingdom and publish SPRAT which is full of construction projects. Almost every Radio-Society run and support a QRP department. There is also the SV-QRP group and their bimonthly e-magazine sv-qrp!
I like to collect awards. Can I still do so with QRP?



Yes! There are many, many awards issued just for QRP operation. These
range from a DX contest with QRP endorsement to the Miles Per Watt Award .
Many other contests also provide a special QRP award such as the ARRL's
Sweepstakes or the CQ World Wide DX contest.
What are some of the limits of QRP?
QRP is not push-button communications! There will be times when your 2
watts just won't cut it. Band conditions, QRM, sunspots. and QRN all take
their toll on a 2 watt signal. There will be times when your 2 watts of RF won't
be enough to make a contact. Some modes don't seem to work as well as others. SSB, for example, is much harder to do with QRP power levels because everyone likes that arm-chair copy. You won't be armchair copy most of the lime on SSB. AM phone is really tough on QRP! It's possible to work All EU with AM phone on the 10 meter band using QRP, but on 75 meters and 40 meters  its not going to fly!


I'm on a limited budget. Would QRP be the best way to go to enter ham
radio?

QRP means low power, not inferior equipment! Don'1 get the two mixed together. 

You could pick up a simple Kit at a hamfest or E-bay for under 50Euro and have a ball, or your could drop five thousand for an YAESU FT-5000, turn the drive down. and run QRP too. While it is true you can pick up a brand-new rig such as the K-1 QRP mono-band rig for about 200Euro, compared to about 1.000E for an entry-level 100 watt rig, going QRP would save you money, but at a cost of only one band and being stuck with CW only.

If I start to operate QRP, what's in it for me?
No matter what you do in life, you get out what you put in. QRP really boosts your ego. Breaking a DX pile-up with 2 watts will keep a smile on your face for weeks. Working the east Coast with 1 watt from a transmitter you
put together with your own hands is one of the best ways to generate those
warm fuzzy feelings. If you're tired of the quick, "Hi. Rig here is .... Weather here is ... Five-Nine..." type of QSO, give QRP operation a try. And if it's nothing else -it's FUN!

Thursday, 9 February 2017

Old wires to new glory!


When in summer of 2008, Southgate Amateur Radio Club changed the meeting venue we the members left behind a shipping container full of junk. Eventually we had to clear it before the landowners take it to the scrap-yard. More than 2 decades of bits 'n' pieces were in there! All from utterly junk to precious gemstones. Like the 5/8 base antenna I have show you, decommissioned from HMS Belfast. Other pieces found their way to Kempton Park Rally or the Dunstable Downs Rally. Some of them even found a homestead in Greece sold at RAAG hamfest or Larisa's one. Some of the container founds I kept for myself and this bunch of wires is one of them. SARC wasn't always an elderly peoples radio-club. They were used to play radio almost every Sunday and they were participating the Field Day Exercise every single year. These tangled wires have serve their purpose as wire antennas, Dipoles and Deltas, and they have prove they deserve respect! Today I unrolled and untangled the bunches with care due to kinks, measure and mark them and then rerolled the way you see in the photos. I will use some of them to make my 160m-80m40m multiband dipole! In other words I will restore them to their former glory by using the way they suppose to and communicate the World!
Any surplus left, porcelain dogbone insulator, tags with use/length of the antenna etc. will decorate my Wall-Of-Fame. That amongst other personal achievements!


Το καλοκαίρι του 2008 ο τόπος συνάντησης του SARC άλλαξε και για λίγο διάστημα αφήσαμε πίσω ένα κοντέϊνερ, μέχρι να εξετάσουμε την πιθανότητα μετεγκατάστασήςς του, γεμάτο "σαβούρα". Βέβαια όπως πολύ σωστά λένε "η σαβούρα του ενός, είναι, ο θησαυρός του άλλου"! Ήταν ένα τεράστιο junk-box γεμάτο με ότι δεν μπορούσαν ή δεν ήθελαν τα μέλη να έχουν σπίτι τους. Αφού λοιπόν ο καθένας πήρε τα δικά του κι αφού αποφασίστηκε τι και ποιά κομμάτια θε επωλούντω στα διάφορα ραδιοπαζάρια, μπήκα κι εγώ και "σκούπισα". Ότι έμεινε πίω, πραγματικά έπρεπε να μείνει. Πολλά πράγματα από αυτά που πήρα με την απόλυτη συγκατάθεση φυσικά των μελλών, φίλλοι οι περισσότεροι, πωλήθησαν στα ραδιοπάζαρα της ΕΕΡ και της Λάρισας. Από αυτά τα οποία έχω κρατήσει, είπαμε έχω ένα junk-box 160κ.μ. σιγά-σιγά και δωθήσεις ευκαιρίας θα σας τα παρουσιάζω. Σήμερα ανέλαβα να συμμαζέψω τα σύρματα, να τα κάνω σωστές κουλούρες και να μετρήσω τα μήκη τους. Τώρα έχω μία εικόνα για το ποιά και πόσα θα χρησιμοποιήσω για το δίπολο των Πολλών Μέτρων. 160m-8-m-40m.

Δοθείσης της ευκαιρίας σας ενημερώνω ότι υπάρχει το 7 strands 16 swg STRANDED COPPER wire και το PVC COATED WIRE 16 swg προς πώληση. Ααμφότερα ασυγκρίτως καλύτερα από κάποια.. αταλοσύρματα!

Wednesday, 8 February 2017

Can you guess?


Other than the Greek scribings, can you guess what is that.
Hint: It dates back in 1977-1078.
Tip: DO NOT try to duplicate.


The first photo is the original schematic hand-draw by Yiannis SK now.
The second one is my try to decipher Yannis scribings doing a bit of better job!
The third is the schematic of a crude Full Wave Rectifier and power supply.P/S



Ξέρετε τι είναι αυτό?
Βασικά είναι μία πολύ επικίνδυνη κατασκευή σε σχέδιο του καλού φίλου και συμμαθητή, μακαρίτη τώρα, Γιάννη Σαμ.
Αποκωδικοποίησα τα δικά του ορνιθοσκαλίσματα με δικά μου κοκοροσκαλίσματα!
Εις ανάμνηση παλαιών ημερών περασμένων δεκαετιών και περασμένου αιώνα.
Σνιφ! Συγκινήθηκα! 

Sunday, 29 January 2017

Ferrite or Powder?


Ferrite or Powder? keep reading... 


Διαφορές των στρογγυλών μικρών μαύρων αντικειμένων τα οποία είθισται να συζευγνύουν βαθμίδες μεταξύ των (γιατί και η κάθοδος προς κεραία, βαθμίδες είναι!). Το BPSK-31 στο οποίο έχω αφοσιωθεί τελευταία με κράτησε πίσω στην Ελληνική απόδοση αλλά, θα το κάνω πολύ σύντομα.

Thursday, 26 January 2017

TX Factor 14


Enjoy part two of our informative series on HF and VHF propagation. Steve Nichols G0KYA concludes with his explanation on how space weather affects our ability to communicate on the HF bands. Bob parts with some cash at Hamfest and Mike chats to Phil Willis M0PHI and Cathy Clark G1GQJ, two movers and shakers in the world of amateur radio.

Wednesday, 25 January 2017

Going digital a.k.a. Simple PSK31 Interface!

I made a basic PSK31 moden for my digital quest!
This the schematic and my homebrew follows.
Mind you that I am not using any resistors.



Tuesday, 24 January 2017

Wednesday, 18 January 2017

Controversies!

the ANTENNA

the STATION

the LOCATION

a station is as good as it's antenna (and the surroundings!)

Στην γούβα κι αυτός. Κρίμα!




Monday, 16 January 2017

The Boeing 707 HF antenna coupler

2. Antenna Couplers

The Automatic Antenna Coupler production provided cash flow to keep the plants open in the '50s and early '60s. Couplers were needed for long range over the ocean communications. As illustrated on the right for the KC-135, tail tops or wing tip installations were common.

2.1 The Antenna Coupler Program

Contributed by Marc Shoquist, Project Engineer on Antenna Coupler Development - 1951 U of M graduate, Electrical Engineering. Joined ERA in 1953 (34 years with ERA/Sperry)
     ERA took on many study contracts from the government during its early years and one of the most successful was the Antenna Coupler program which resulted in the production of over 12,000 units for military and commercial aircraft communication systems during the 1953 – 1970 period, after which the program was transferred to Sperry Marine Systems. It was the largest production program ERA had in the mid 1950’s and during the 1953 – 1956 period represented over 25% of the sales and most of the profits for the division. During the 1953 – 70 period, there were three generations of antenna couplers developed; the initial model which used vacuum tubes, an all solid- state unit for the Boeing Jet aircraft developed in 1955 and finally a high tuning speed unit for the General Dynamics B-58 Hustler Bomber developed in 1958.
    The coupler consisted of a variable vacuum capacitor and inductor coil, each driven by servo motors which were tuned to automatically match the antenna impedance to the coaxial transmission cable. The tuning elements were controlled by a discriminator which sensed the resistance and phase at the termination of the coaxial cable to the antenna. The coupler tuned wire, probe and tail cap antennas in the High Frequency (HF) 2-30 MHz range. The 707 used a probe antenna mounted on top of the tail fin so the coupler was exposed to the outside environment where temperatures were frequently below – 65 degrees F. Moreover, the coupler after being in a cold soak at this temperature had to start up an complete the tuning within 10 seconds, a no easy task. In addition, the probe antenna impedance was so miss-matched at low frequencies that the coupling voltage to the antenna was over 20,000 volts. The early units were pressurized with dry nitrogen and sealed with a soldered seal. Later a Teflon coated O-ring seal was developed which was able to hold a vacuum over a long period, which simplified maintenance of the unit.
    In the early 1950’s RCA won an Air Force contract for the development of the new ARC-21 Airborne HF Communication System which included an antenna coupler. During its development, RCA experienced problems in developing the antenna coupler and the Air Force gave ERA a study contract as a fall back. The ERA coupler proved to be superior to the RCA unit thus ERA became the sole source production supplier of the coupler for the system. Initially, it was sold directly to Boeing who sold it as “contractor supplied equipment” in aircraft delivered to the Air Force. Over 7000 units were sold to the Air Force during the 1953-70 period and were used on about 10 different aircraft.  The Coupler assembly line is shown at the right.
         I joined the company in 1953 at the time the first generation coupler was entering production. The coupler engineering staff at that time was small and headed by Fran Biltz under the Communications Group directed by Carl Swanson. Other staff engineers included Leon Sabine, Robert Einfeldt, Bruce Sifford, Manny Block, Howard Peterson, and two technicians, Morris “Pappy” Pappenfuss and Oscar Haymen. Carl Hiat, a development engineer had transferred to manufacturing to assist in the transition of the Coupler into production. Fred Hargesheimer headed marketing and Don Blattie did the contracting. Al Meuller led Customer service, which included the training of the supervisors and technicians of the foreign airlines maintenance shops. {Editor's note: Al was the first VIP Club President in 1980.}
      My initial coupler assignment was conducting the Qualification Test of the coupler and writing the report. Later I was the field test engineer for system tests of the Arc 21 communication tests on the B-47 aircraft at McDill Air Force base. This was followed by my supervision of a coupler field modification program at Smoky Hill Air Force base in Kansas. I returned in 1955 to head a development group and became the project engineer for the 2nd generation coupler which was developed for the Boeing 707 aircraft.     
      In 1955, Boeing developed the 707 Commercial jet aircraft and based on the performance of the ERA Coupler awarded ERA the contract to develop the coupler without a competition. This launched the development of the 2nd generation all solid-state coupler, which was the first of its type in industry. The Boeing 707 initiated Boeing’s return to the commercial aircraft business, which they continue to lead as the world’s largest supplier. The 707 was sold to over 40 airlines worldwide and there was an ERA coupler on every one of them. This was the model 3250 shown at the leftt. The tube-like unit was mounted either in the vertical stabilizer or at the end of a wing. The control unit (rectangular box) was mounted adjacent to the radio set.   
     One of the highlights of the military business was supplying the couplers for the Presidents Air Force One planes. There were six couplers including spares on every aircraft and their installation received special treatment by our engineers and field service staff. Robert Brown, who led our field service group made the initial installation in 1956 at Boeing before they were delivered. The system was upgraded in 1965 and Ernie Griffith a lead engineer on the coupler did the installations at Andrews Air Force Base near Washington DC where the fleet of Presidential aircraft and helicopters are based. I went along to chat with the Boeing representatives and just touring this specially equipped aircraft was worth the trip.
     I was project engineer for the 3rd generation coupler for the Air Force B-58 Hustler Bomber. By the time the B-58 Coupler contract was won in 1958, the engineering staff which then included drafting had grown to 70 people and engineers which were added for the 707 project development included John Moe, Charles Class, Allen Anderson, Mick Alsop, Al Sorenson, Paul Richardson, Howard Chen, and Bob Rife. By this time, the division had become recognized as a specialist in the development of this product to the extent that when Hughes won the contract for the development of the new ARC-68 HF Communication system, they selected us as the coupler supplier, rather than develop it themselves.
     While the initial coupler business was with the Air Force and Boeing, in 1967 the company was successful in displacing Collins Radio as the supplier of the Coupler on the Lockheed P-3C Patrol aircraft for the Navy. Winning this contract was a milestone in extending the airborne coupler business to other services. In 1984, I visited Sperry Marine systems 15 years after they the Coupler Business had been transferred to them and supplying couplers for the P-3C was the major source of their revenue for the coupler military business. The P-3 coupler is shown here. [Marc Shoquist] 
    The antenna coupler is very much a part of the military history of ERA/Univac/LM. I think that the first one was designed for the KC130 "flying filling station", the prototype of the Boeing 707. The USAF let Boeing build three 707s on government tooling and then made Boeing build their own tooling for the commercial plane. This gave Boeing several years to test fly those planes. In the early 1930's Boeing had built a few prototype B-17s. The depression stopped the production. A Dr. Reynolds invented modern flight testing and spent years working on those prototypes. That is why the B-17 was such a good plane. Dr. Reynolds designed the B-29 at the start of WW II. The first prototype killed him. His niece worked for Remington Rand Univac about 1958. I met her because her parents lived across the street from my parents in Tegucigalpa, Honduras. It's a small world. At one time Margaret might have been the most knowledgeable person in the plant on transistor physics as a result of her programming in that area. [Harry Wise]
The photo at the left was taken in the 1950s at the then ERA plant 3, located on University Avenue between the Cleveland and Raymond intersections.

Αυτή είναι η ιστορία του αυτόματου κάπλερ για κεραίες αεροπλάνου της ERA. Στο διάστημα 1953-1970, κατασκευάστηκαν 12000 κομμάτια σε τρεις βελτιώσεις της βασικής ιδέας. Το κάπλερ αποτελείτο από έναν μεταβλητό πυκνωτή κενού κι ένα μεταβλητό πηνίο, τα οποία μεταβάλλονταν με σερβομοτέρ για να επιτύχουν τον κατάλληλο συντονισμό και να προσαρμόσουν την σύνθετη αντίσταση της κεραίας με αυτή του ομοαξονικού καλωδίου. Το κάπλερ αυτό μπορούσε να συντονίσει την όποια κεραία τύχαινε να έχει το αεροπλάνο στην μπάντα των HF 2-30MHz. Επί του προκειμένου το 707 χρησιμοποιούσε κεραία ακίδας στην κορυφή του πίσω πτερυγίου κι έτσι το κάπλερ ήταν εκτεθειμένο σε εξωτερικές θερμοκρασίες της τάξης των -53° Κελσίου. Έπειτα το κάπλερ θα έπρεπε να ξεκινήσει να συντονίζει μέσα σε 10 δευτερόλεπτα από την εντολή ενώ ταυτόχρονα ήταν παγωμένο απ΄ τις εξωτερικές θερμοκρασίες. Επιπροσθέτως ήτο και το γεγονός ότι στις χαμηλές συχνότητες ήταν τόσο μεγάλη η δυσπροσαρμογή έτσι ώστε εμφανίζονταν τάσεις της τάξης και πάνω των 20.000 Βόλτ. Οι πρώτες μονάδες συμπίεζαν ξηρό άζωτο και σφράγιζαν τον δακτύλιο με κόλληση και κολλητήρι. Αργότερα χρησιμοποιούσαν στεγανοποιητικό δακτύλιο από τεφλόν, πράγμα που απλοποιούσε την συντήρηση αφού το κενό μέσα στο κάπλερ διατηρείτο για πολύ διάστημα.
Αυτό είναι σε γενικές γραμμές το σκεπτικό και η λειτουργία του κάπλερ και της τότε κεραίας των αεροσκαφών αφού σήμερα χρησιμοποιούν το κάθετο τμήμα του πίσω πτερύγιου ως κεραία. Έψαξα και βρήκα φωτογραφίες στο διαδίκτυο με κεραίες αεροσκαφών αλλά σας εφιστώ την προσοχή σε δύο βασικές λεπτομέρειες. Οι κεραίες είναι πολύ μικρές ως προς το μήκος κύματος και "πετούν" πολύ ψηλά στην ατμόσφαιρα μακριά από εμπόδια και παρεμβολές! 
Ίσως η ανάρτηση αυτή να δώσει το κέντρισμα σ' έναν φίλο ραδιοερασιτέχνη και τεχνικό της ΟΑ να μας γράψει μερικές αράδες περισσότερες γιαυτό το θέμα.
Αεροσκάφος 707 της ΟΑ με την probe antenna.


Fin tail antenna.


A modern version of fin tail antenna.