The Cadet Rx!

At the Kempton Park Rally November of 2012, RSGB had on sale old kits constructed and presented in the RadCom.
I fancied a little fellow and I had bought it without any second thought. After all it was, and still is, a piece of History!
It was obviously a receiver, more likely a Direct Conversion Receiver(DCR) one. The only distinction was a name printed in dymo tape.
THE CADET!
For a couple of years I searched on internet for "the cadet" but nothing more than the well known OPEL car model.
I was doing a search the other day and I was very persistent this time so luck was with me. There was a description of a 3 Band HF DC radio featured in an old SPRAT issue which in turn it was based on the Cadet radio as it was featured in RadCom October of 1973! Wow!
I am lucky to have the complete volume of RadComs up to present day so a trip back to 1973 was a matter of a couple of clicks away!
And there it was!

It is indeed a Direct Conversion receiver for the 20 and 15 meter bands designed by a listener! Mr. J. Young BRS33339! Imagine the construction level of the newcomers to the hobby that the radio you can see in full colour, it was easy enough to be built by them! It was and still is an excellent piece of kit of a bygone era.

I can assure you that although it lacks of TLC, i.e. spray at the Balance pot or clean & grease the variable caps bearings, it receives amazingly well!

21Megs are practically dead for now but on 20 I can hear stations I am copying with my dedicated radios!

Ladies 'n' Gents... The Cadet!

A fine piece of Radio History!

Πριν μερικά χρόνια σε ένα πραγματικό Ραδιοερασιτεχνικό πανηγύρι, το Kempton Park Rally, είδα στον πάγκο της RSGB να πωλούνται παλαιές κατασκευές οι οποίες είχαν δημοσιευτεί στο περιοδικό RadCom και τώρα μάλλον τους έπιαναν τον χώρο αφού δεν ήταν δα και μουσειακά κομμάτια!

Ακόμα και για τους βερνιέρους άξιζε να το αγοράσω το μικράκι για το οπίο κανένας δεν είχε να μου δώσει περισσότερες πληροφορίες πέραν του εμφανούς, το ότι ήταν δέκτης δηλαδή(!) και μάλιστα Δέκτης DC!

Δεν θυμάμαι το ποσό το οποίο είχα αγοράσει τον δέκτη, υποθέτω ότι ήταν κάπου στις 10 με 15 λίρες. Για μια κατασκευή παρουσιασμένη στο RadCom και μέσα από την αποθήκη της RSGB σίγουρα δεν ήταν μεγάλο το ποσό!

Παρέα με τις άλλες αγορές της ημέρας είχε επιστρέψει σπίτι για να καταχωνιαστεί σε μιά γωνιά του junk-room και τελικά να επιστρέψει μαζί μου στην Ελλάδα. Αφού μάζεψε κι εδώ αρκετή σκόνη αποφάσισα να του "ρίξω μιά ματιά".

Και κόλλησα!

Ακόμα και με μη απόλυτα ευθυγραμμισμένο δέκτη άκουγε! Και όχι μόνο άκουγε αλλά άκουγε ωραία και με ποιότητα ήχου! Όσες λιγότερες βαθμίδες και ετεροδυνώσεις σ' έναν δέκτη τόση καλύτερη η πιστότητα και η ποιότητα του ήχου, χωρίς φυσικά να υστερεί σε ευαισθησία αφού δεν υπάρχουν απώλειες στις βαθμίδες!

Σειρά έχει το ψέκασμα και ο καθαρισμός του ποτενσιόμετρου του Μείκτη και λίγο καθάρισμα/γρασάρισμα στα κινούμενα μέρη των μεταβλητών και των βερνιέρων. Ισως και αλλαγή του AF ενισχυτή για να το συνδέω με μεγάφωνο κι όχι με τα ακουστικά, και να ακούω με τον ίδιο δέκτη έτσι όπως άκουγαν οι συνάδελφοι το 1973!

Ένα κομμάτι πραγματικής Ιστορίας!

QSLing!

A QSL card is the final courtesy of a QSO - or is it?

 QSLing was the norm when I came into the Hobby in the late 1960s. In those days I was A3699, a short wave receiving station Member of the RSGB. I remember getting some cards printed by A B looe,in Cornwall, paid for by my father. I wish I had one left but they have all gone.
 In those days QSLing direct was the only for something like Heard Island or similar and 99% of all QSL cards went via the bureau. We had our own bureau in Scotland at that time run by GM3ITN and I used to wait with great anticipation for an envelope.
 DX seemed more plentiful in those days. For example, most of the islands in the Pacific were still manned by US military personnel and many were amateurs. Very few islands were deemed out of bounds and Scarborough Reef had not yet surfaced.
 Ah, those were the days. Life and amateur radio was simple – no computers,log books were carefully written up, QSL cards were shown off at the local club.
 What difference a few decades make. Computers – you either love them or loath them – are now standing in most shacks. We have automated and semi automated stations, computers making QSOs with other computers(WSJT etc) and many QSOs achieved. Is the QSL card exchange still relevant? And why do we QSL today? With up to 400 watts (depending on your licence) along with multi element Yagis, we can make several thousand QSOs in the 48 hour period of the CQ World Wide contest for example. Do we really need to follow that up with a written postcard confirmation?
 QSL card production and printing is now much less expensive that is used to be and, after the contest, a few button presses and, hey presto, a whole box full of labels just ready to be stuck on the cards and sent to the bureau.
 For my sins, I am a volunteer sub manager for the RSGB QSL Bureau. I have slowly come to realise that QSL card can be a wasteful activity. I am now privy to that waste every quarter when I consign about 30-40% of all cards in my box to my recycling bin. The only people making a profit from all this is the QSL card printers.
 There appears to be a fair number of Scottish stations(I can't speak for the rest of the UK) who are still sending out a card for each and every QSO they make. This is especially so for special event stations who, on occasion, go to extreme and probably expensive lengths to produce a colourful QSL card. How do I know this? Simply because of the number of cards I see going through the bureau marked “undeliverable – not a member of... (whatever Society is applicable)”.
 In every box I get from the bureau there could be up to a hundred cards for G or GW stations who have come up to Scotland either to operate vacation style, or portable or even mobile. They make many QSOs using the GM prefix, but never think to send an SASE to the bureau. I do my best to chase them up, but many are “name and address withheld”. Several clubs come to Scotland each year to activate an island or take part in a contest. Through continuous budgeting, most of these now have appropriate measures for QSL cards in place.
 Back in the old days, you had to be a member of your National Society to send cards out via the bureau but you did not have to be a member to receive cards via the bureau. All you had to do was  keep the bureau with sufficient self addressed and stamped envelopes. This was changed and here in the UK you need to be an RSGB Member to receive cards or pay an annual fee.
 Postage is expensive and bureaux are shipping these cards backwards and forwards, eventually to be destroyed as the recipient isn't a Society Member.
 For me herein lies an anomaly in the process. Every bureau has its own set of rules for delivering and returning cards, some return only “silent key” cards, some perhaps do not return any cards and they are destroyed at source. I find this last example unhelpful as it just encourages second and third tries for a QSL card. However I do appreciate that to re-ship what is really thousands of unwanted cards is an expensive business and somebody has to pay. That “somebody” is us the Members of the RSGB in our case.
  Please review our QSLing policy. Do you need to send cards for a contest contact? Even if you do, does it have to be one for each band? Special event stations often put 'no return card required' on their outgoing card, but if the recipient is not a member of a National Society, the card will not be deliveredin the first place. 
 It is much too easy to just print QSL labels in bulk, or to tick OQRS in Club Log or whatever.Do you honestly want the card and do you have the means in place for it to be delivered.
 Please think before you ink!

THE QSL BUREAU REPLIES 
Tom's unsolicited letter is extremely interesting and his experience is repeated throughout the network of 70 QSL volunteers. Tom rightfully points out that unwanted and uncollected cards cost every member of the Society, including non-QSLers. It's extremely disheartening for out band of QSL volunteers (without whom the system cannot operate and who give of their time to help other Members) to see some 50% of cards go to recycling.

 Like Tom, the daily evidence at the RSGB QSL Bureau is that 100% outgoing QSLing is wasteful and introduces unnecessary delays. There other 21st century options available.  

Tom Wylie GM4FDM
RadCom September 2015

Αξίζει ο κόπος και το κόστος του να στέλνει κάποιος QSL κάρτες.

συγκαλυμμένα ο Αρθρογράφος αλλά και ο "Μπύραρχος" λένε πως όχι!

Σε γενικές γραμμές!

Μεγάλο κόστος, μεγάλος φόρτος εργασίας, συναινούν στην αλλαγή των συνηθισμένων χάρτινων με ηλεκτρονικών καρτών!

The Tripus!

What is a Tripus?

Well, some might know and some might have guessed that it is an invention of Reverence George Dobbs G3RJV. George found that he was constantly going to rallies and seeing meters that he could not check or determine their sensitivity. So he designed the Tripus which have taken on stage further by adding another cell, thus enabling it to check LEDs and seven segment displays.

This simple unit consisting of two cells, four resistors and three crocodile clip on leads which are all held together with tape.

The circuit diagram shows the unit works. When the Black and the Red leads are shorted together, 10miliamps flows across the circuit and when the Black and Yellow leads shorted together,100 microamps will flow.

When testing meters, start with the Black and Yellow leads and if the meters reads half scale the movement sensitivity is 200μA FSD(Full Scale Deflection). If the meter flies over to FSD it is more sensitive than 100microamps, but as the most sensitive meter that you are likely to find will be 50microamps, the meter should not be damaged.

If the meter hardly deflects at all, then its sensitivity is obviously low, and this is where to 10miliamp Red lead can be used! The result obtained enables the sensitivity to be estimated in the same way as with the Yellow lead.

For testing LEDs we use the 10mA lead and this could be enough to illuminate all colours if the battery is fully charged. We can also tell if seven segments displays are common anode or common cathode, as we know the polarity of the battery within the Tripus.

For charging my Tripus, I clip the Black and the Yellow leads onto my nicad charger and charge in the normal way for the cell size used.

And why is it called the Tripus?

Well, it only has three legs!

Ian Keyser G3ROO/Radcom 9402/sv3auw

Μια μικρή και εύκολη κατασκευή για τον έλεγχο των οργάνων και LEDs τα οποία εμφανίζονται στα ham-οπάζαρα.

Ζωντανά ή πεθαμένα! 

Ε, άμα πιά!

Η εσωτερική κεραία μου, είναι ΣΥΝΗΘΩΣ, καλύτερη από το off-center-fed ή windom δίπολό μου!

Για πες μας λοιπόν να μάθουμε κι εμείς οι αδαείς οι οποίοι αγοράζουμε το RadCom  να "ξεστραβωθούμε" με τα reviews/παρουσιάσεις των κεραιών τα οποία κάνεις.

Φταίει το δίπολο που δεν ακούει?

Φταίει το δίπολο γιατί είναι Windom?

Φταίει ο εγκαταστάτης?

Ε???

για πες...

για πες...

"...an outdoor OCF dipole for 20-10m, but switched to my indoor dipole which is usually better..."

An indoor antenna USUALLY better than an outdoor antenna?

Wow!

What's the problem Steve?

Is it this particular antenna, is it the OCF, what?

Then again why don't you use one of these  antennas you review in Radcom and they get excellent scores?!

Like this Halfwave length of 7 meters, Ground Plane with NO radials, Moonraker GP-2500?

Or any other metal stick with lots of coax cable rolls as feeder?

Enlight us please!

kind regards and 73

Panos

sv3auw/m0lpt

---

From: steve95446
To: GQRP@yahoogroups.com
Sent: Sunday, 21 October 2012, 17:00
Subject: [GQRP] 10m CW

Well blow me! I say that 28.060MHz isn't getting much use, send out a CQ and Ed W1GUE (New Hampshire) comes right back, running 5W from a TS480 to a dipole.

I was running 5W to an outdoor OCF dipole for 20-10m, but switched to my indoor dipole which is usually better. 

The MFJ Mag Loop in the loft is similar too.

A lot of QSB, and he reported QRM, but we made it.

This is fun! Should make more of an effort to get on the band really.

Steve G0KYA

Η απάντηση του Steve. 
Εξωτερική Windom μήκους 10m και εσωτερικά full size δίπολα!
Με τα εσωτερικά δίπολα "να σπάνε δοκάρια"!
Σε αυτή την περίπτωση απλά ντρέπεσαι να πεις ότι έχεις εξωτερική(!) κεραία!

Hi Panos,

Well, the current antenna outside is a commercial 10m long OCF dipole that works on 20, 15m and 10m with a 4:1 balun and can be pushed onto 17m with an ATU.

It works well as a compromise antenna on the bands above 20m. 

In the loft are parallel-fed dipoles for 40m, 20, 17 and 10m (with the 40m zig-zag dipole working as three-half waves on 15m).

There is also an MFJ 1786 mag loop in the loft and a 20m EH.

The dipoles (which were featured in the GQRP antenna book) work very well, and are slightly higher than the outdoor antenna. But you have to be careful with EMC pproblems and so it is best to reduce power (not a problem with QRP).

The coax run is shorter to the loft and they are not a compromise, which may explain why they are often better. Also the radiation pattern on the OCDF on 10m breaks into lobes, whereas the loft-mounted 10m dipole beams east-west.

I worked T32C on 10m SSB with the loft antennna, much to my surprise, although it took 100W to do it.

I also have a 99ft W5GI "Mystery Antenna" dipole for 80 and 40m over the roof, which has been tested for the past six months and works well on those bands, but isn't so good higher up.

If you read some of my reviews you will see that I often compare the tested antennas with the dipoles. If the antenna under test is not as good I always say so. I can't comment on individual antennas, but you have to read the results to make up your own mind as to their efficiency.

This is the third house where I have used indoor loft-mounted dipoles and they have often beaten external antennas - notably a 2-element minibeam on 20m that cost more than £450 and was supported on a 10m Altron mast. That was annoying!

I have to yet to find the ultimate outdoor stealthy multi-band antenna, but the quest goes on!

I think I am going to have to knock up some parallel-fed dipoles for 20-15-10m to replace the OCFD.

Steve G0KYA

Σκέψεις!

Σκεπτόμουν όλο το Σ/Κ για το αν θα έπρεπε να στείλω αυτό το e-mail.

To RadCom and Practical Wireless

 

If you are in a competition of who is going to deceive new comers to buy CB boxes as RADIOS and metal junk as ANTENNAS, you are in a good way.

The next generation of RadioAmateurs will do appreciate that and will be grateful of your efforts.

Panagiotis

SV3AUW/M0LPT

Προς το RadCom και το Practical Wireless

Αν εσείς οι δύο είστε σε διαγωνισμό για το ποιός θα ξεγελάσει τους νεοεισερχόμενους να αγοράσουν CB για πομποδέκτες και μεταλλικά σκουπίδια για κεραίες, είστε σε καλό δρόμο.

Η επόμενη γενεά Ραδιοερασιτεχνών θα το εκτιμήσει αυτό και θα είναι υπόχρεη για τις προσπάθειές σας.

Τελικά δεν αξίζει τον κόπο.

Αν στην χώρα του Louis Varney G5RV, Les Moxon G6XN και πάρα πολλών άλλων(G3TSO, G3PLX, G3XJP, G1FTU...)

επιβιώνουν τέτοια περιοδικά με τέτοιους εκδότες, I rest my case που λένε εδώ, παύω να μιλώ.

Όσο μπορώ και δύναμαι, από την θέση μου θα προσπαθώ να διορθώνω τα κακώς κείμενα.

Από κάποιο σημείο και μετά, όποιος δεν έχει μυαλό έχει... λεφτά (για ξόδεμα)!

Τα ράδιο-νέα από τις Αποικίες!

Μετά από απουσία ενός περίπου μήνα, χρειάστηκε να επιστρέψω για μιά εβδομάδα στις αποικίες.

Το γραμματοκιβώτιο ήταν γεμάτο από αλληλογραφία. Μεταξύ αυτής ήταν και τα νέα τεύχη, Ιουνίου, του RadCom και του Practical Wireless.

Οι πάρα-κάτω φωτογραφίες αναφέρονται στην Ελληνική πρωτιά του SV2DCD στους 70MHz όπως και του SV8CS με τον ZS6NK!

ΠΑΝΤΑ ΤΕΤΟΙΑ ΠΑΙΔΙΑ!!!

Το δε Practical Wireless μας δίνει τον τρόπο να μειώσουμε την ισχύ ενός FT-817, ή όποιου άλλου πομποδέκτη, επεμβαίνοντας στο κύκλωμα ALC.

Πως αλλιώς θα είμαστε σύννομοι με την προτροπή τουν χρυσοκάνθαρων μανδαρίνων με το “καμμένο ακατοίκητο” για τον περιορισμό της ERP ισχύος σε 146 watts?!!

Αφού φυσικά θα χρησιμοποιούμε την super-duper κατευθυνόμενη κεραία Βραχέων με κέρδος 16.9897db ή πολλαπλασιάζοντας 50 φορές την ισχύ εξόδου του Π/Δ?!

Τον γνωρίζετε?

Από μικρός φαινότανε, τι σόι ...εφευρέτης θα γινότανε!!!

Είναι ο Sir Clive Sinclair σε νεαρά πλην δημιουργική ηλικία!

Μίνι δέκτης με το σχέδιό του!

RadCom October 2009

Το τελευταίο τεύχος του RadCom και τα περιεχόμενά του.

Κάντε κλικ στην φωτογραφία για μεγέθυνση.

Η σύγκριση και τα συμπεράσματα δικά σας!