.

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

Tuesday, 23 October 2012

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