Category: Antennas

HAMsmithing – DIY Walking Stick/Antenna Mast

A week ago I has a try of my Walking Stick/Antenna Mast made of PVC pipe. My plans changed down the road and the test was limited to the antenna fitment/adapter section of it.

I had it redone to fix a dimensional mistake, and so I took the chance to grab some photos of the whole stick/mast build.


This is how the two sections are connected together. They are 25 and 20mm electrical conduit pipes cut a bit longer than usual waking baton length (you will need the extra length walking downhill).

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My own take into Winter Field Day

By the end of each January it is Winter Field Day time. Where HAM operators run their radios under field conditions. Some are as bold as to do this on the wild, in a tent on the snow.

Inspired by the concept, I had my own version of two days ago. No, I do not do HF yet, and it wasn’t actually winter. Over here we have a spell of spring-like sunny days on the last third of January, and that day it was 14 degrees C at 3000ft.

So I took the road to the gazebo I frequent somewhere on our mountain. I had taken most of my VHF equipment with me and a new DIY antenna pole to test. Also scheduled were cutting two new wire dipole antennas, using the RTL-SDR receiver with my phonen and maybe testing my simplex repeater too. And add some bush crafting in the process.

I spend Friday and Saturday making the pole and organizing my gear.


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Το δικό μου Winter Field Day

A note for the foreign readers. The same article will appear in English very soon.

Κάθε χρόνο προς τα τέλη του Ιανουαρίου διεξάγετε ένα διεθνές ραδιοερασιτεχνικό event, όπου οι ραδιοερασιτέχνες μεταφέρουν τον εξοπλισμό τους έξω, στο ύπαιθρο, και τους λειτουργούν με ότι μέσα μπορούν να κουβαλήσουν. Το event έχει και διαγωνιστική χροιά, αλλά ο καθένας μπορεί να μετέχει όπως μπορεί.

Δυστυχώς δεν κατάφερα να συμμετέχω αυτό το ΣΚ, αλλά χθες πήρα τον εξοπλισμό μου και κατευθύνθηκα προς το συνηθισμένο κιόσκι κάπου στο βουνό μας.

Σκοπός μου ήταν να δοκιμάσω ένα νέο ιστό κεραίας, να κατασκευάσω 2 νέα δίπολα και να τσεκάρω την λειτουργία ενός ακόμη, μακριά από τον ηλεκτρονικό θόρυβο της πόλης, αλλά και να περάσω καλά.

Όλα ξεκίνησαν με την προετοιμασία του εξοπλισμού μου. Για πρώτη φορά θα έπρεπε να πάρω μαζί μου σχεδόν το σύνολο του και θα έπρεπε να τον οργανώσω κατάλληλα.

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HAMsmithing – DIY Receive-only Antennas for RTL-SDR Dongles

So, after putting my cell phone in to use and running RTL-SDR radio listening apps, it was time to make 2 antennas for the dongle, the original one being Poor.

So I got me a coffee, nerves of steel, and started soldering on two MCX window Connectors for RG-174 cables.

The wire was sourced from a surveillance camera installation cable. It has 3 single conductors and a coax wire that seems to be RG-59 75ohm one.

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A Small, Pocketable Antenna Kit for Handheld Radios

I call it the Giveaway Antenna Kit. Because it has the capability to be adapted to any handheld radio, that is, the antenna connector style of any handheld radio. So you can have it in your larger radio kit, and give it away to anyone in need without bothering for compatibility with his radio.

The basic idea stems from this idea by Bret of Survival Comms Youtube Channel . The use of the handheld radio’s own (actually aftermarket improved) antenna on a groundplane kit. In my built, the groundplane (radials’) kit is much simpler and easier to use. You just attach the antenna kit wire to fit your HT.



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Ενα μικρό Κιτ Εξωτερικής Αντένας για το Φορητό σας Ασύρματο

Οι φορητοί μας ασύρματοι υστερούν στην αποτελεσματικότητα τους για δύο λόγους. Έχουν μέτρια , έως κακή κεραία, και δεύτερον έχουν χαμηλή ισχύ.

Μπορούν όμως να βελτιωθούν προσθέτοντας μια καλύτερη κεραία (κάντε το οπωσδήποτε) και επίσης -αν μένουμε σταθεροί- μια κεραία βάσης.

Η ιδέα μου βασίζεται στην ιδέα του Bret από το Survival Comms. Στην ουσία μετατρέπει την βελτιωμένη κεραία του φορητού ασυρμάτου σε μια groundplane κεραία βάσης, κατασκευάζοντας ένα προσαρμογέα με radials.


Η κατασκευή μου προχωρά παραπέρα δημιουργώντας ένα εύκολα κατασκευάσιμο κιτ radials.

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HAMsmithing – September 2017

Just as September was ending, I spent quite some time on small HAM projects.

1. I received the connectors and cables I ordered, so I sat down making cables for each DIY antenna I have.

2. I used some leftover PVC pipe to add 2 more sections in my collapsible antenna pole. Each section is 130cm (about 1.5 yards long), the wider my car trunk will allow. That makes for about 7 yards total height, just short of what one would need to make a sloping longwire antenna.

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A Practical Interpretation of Antenna Gain, donuts included.

Antenna gain is not an easy notion for a new radio operator to pick up. Some even go as far as supposing that the antenna gain shows the increase in radio power.

But is not that the actual energy radiated is increased by the better antenna, this is not allowed by the law of the conservation of energy. It is because the radiated energy is handled, shaped-formed and directed better towards you.

A look at wikipedia tells us: ” In electromagnetics, an antenna’s power gain or simply gain is a key performance number which combines the antenna’s directivity and electrical efficiency. In a transmitting antenna, the gain describes how well the antenna converts input power into radio waves headed in a specified direction. In a receiving antenna, the gain describes how well the antenna converts radio waves arriving from a specified direction into electrical power.”

Now this explanation is correct but let’s make it simpler.

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