Noun[edit]
bulge (plural bulges)
- Something sticking out from a surface; a swelling, protuberant part; a bending outward, especially when caused by pressure.
It was not particular obvious at first glance and it was very confusing measuring continuity and reading low loss(with a pinch of salt) with the AA. Not to mention that I still had an excellent reception !
But it was malfunctioning, and I will tell you the whole story.
There was no problem working with 5 or 10 Watts last Sunday during the QRP Spring Gathering. Turning rig's power high it was a come and go situation and using the Lin Amp to clear the QRG for the fellow qrpers, it was almost infinite swr.
First I check for electrical continuity between both PL-259 and strange enough there it was. (There it was the problem too!)
Then I redone the solders at my homebrew balun just to be on the safe side but the malfunction persisted.
After that, I used my MFJ-259 Antenna Analyser to see the loss of the 1 meter of coax cable I am using to feed the output of my tuner to the current balun outside of the shack. The losses was 0.6db. Sounds reasonable but for a length of only 1 meter of coax, it was a bit odd.
So as a last resort I started running my finger tips onto the cable trying to feel something odd and there it was. A couple of centimetres from the balun side, I felt something that had to go for a thorough inspection even if it meant a scalpel, a pair of cutters and a vice!
And there it was ladies and gents.
An RF bulge, created from an RF voltage peak due to excessive resistance and reactance at a given frequency.
I cut and discard the damaged piece of coax cable and things are back to normal now!
This method of feeding a balun and ladder-line is described by Doug W1FB in his book, W1FB's Antenna Notebook, where he propose the connection of the in-shack tuner with the balun outside, using a length of coaxial cable no more than 8 feet. Mine was 3ft!
But it was malfunctioning, and I will tell you the whole story.
There was no problem working with 5 or 10 Watts last Sunday during the QRP Spring Gathering. Turning rig's power high it was a come and go situation and using the Lin Amp to clear the QRG for the fellow qrpers, it was almost infinite swr.
First I check for electrical continuity between both PL-259 and strange enough there it was. (There it was the problem too!)
Then I redone the solders at my homebrew balun just to be on the safe side but the malfunction persisted.
After that, I used my MFJ-259 Antenna Analyser to see the loss of the 1 meter of coax cable I am using to feed the output of my tuner to the current balun outside of the shack. The losses was 0.6db. Sounds reasonable but for a length of only 1 meter of coax, it was a bit odd.
So as a last resort I started running my finger tips onto the cable trying to feel something odd and there it was. A couple of centimetres from the balun side, I felt something that had to go for a thorough inspection even if it meant a scalpel, a pair of cutters and a vice!
And there it was ladies and gents.
An RF bulge, created from an RF voltage peak due to excessive resistance and reactance at a given frequency.
I cut and discard the damaged piece of coax cable and things are back to normal now!
This method of feeding a balun and ladder-line is described by Doug W1FB in his book, W1FB's Antenna Notebook, where he propose the connection of the in-shack tuner with the balun outside, using a length of coaxial cable no more than 8 feet. Mine was 3ft!
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Ονομάζομαι Τάκης Περρέας και αυτό είναι το προσωπικό μου ιστολόγιο, όπου “ιστολόγιο” το Δικτυακό ημερολόγιο!
Εδώ γράφω τις απόψεις μου, τις θέσεις μου, τις μελέτες μου και γενικά ό,τι έχει να κάνει μ' εμένα!
Δεν ζω από το ιστολόγιο, αντίθετα μου αφαιρεί αρκετό χρόνο από την καθημερινότητά μου. Δεν περιμένω να πλουτίσω λοιπόν ούτε από επισκέψεις, ούτε από “κλικ” σε σελίδες!
Με δεδομένη την ανυπαρξία σχολιασμού και ερωτήσεων, επιτρέπω πιά, μόνο σε μέλη να κάνουν σχόλια και ερωτήσεις. Στην περίπτωση που πραγματικά θέλετε να σχολιάσετε ή να ρωτήσετε, στείλτε ένα e-mail για να εγγραφείτε αυτόματα μέλος!
Κάντε όσες τεχνικές ερωτήσεις θέλετε και θα προσπαθήσω να απαντήσω σε όλες με τον καλύτερο και επεξηγηματικότερο τρόπο.
Αυτός είναι ο λόγος άλλωστε, για τον οποίο το ξεκίνησα (άσχετα αν μερικές φορές εγώ ο ίδιος ξεμακραίνω)!