Chaps, Newbie to the magic band....
I have an old 27Mhz Ringo & want to get it up on 50mHz. Seen a few ideas, but finding the "ring" size to be my failing point. (one web site in Italian only, anda mea speaka not la Italiano)
Plenty of diagrams to make into a J-Pole (which is no biggie to do) but with limited recreational time & keenness to make some noise, is this possible?
All comments welcome.
I have been offered a CB ringo. I had thought I might modify it for 6. I'm interested in the outcome of this. I posted a message on this forum about a station master that I converted to 6, so I guess a method similar to what I used could be used to mod a ringo.
The article at the end of the link translated with Google Translator is as follows:
SHAK - TWO 50 Mc
ANTENNA (I8SKG)
After describing the changes to take our RTX-TWO SHAK to operate on the frequency of MC 50, the accessories (calibration circuit and limiting the scale of disturbances Pulse), and the PA for the SSB, I describe a modest and not very difficult to bring change to work in Banda Mk 50, an antenna 27 of RINGO.
The choice of a vertical antenna, in my opinion, it is convenient for use in VHF, and especially for the Mk 50, for those who find themselves surrounded by mountains that prevent successful use of a directional antenna (it's my case for the note).
On the other hand, for the experts working on the 50, it is known that the links in DX occur with the E Sporadic, and that therefore even just a spit of antenna, when this phenomenon is present ..
In closing Sporadic E connections are, as for the 144,-sight, or nearly so.
Now we come to our antenna to change.
The operation was performed on a RINGO the ECO ANTENNAS, namely Article 5 of the catalog.
Main operation is the sawing in the middle of the coil arrangement at the base, so that two turns of which it is formed, it would become, without altering the diameter.
The development is carried out as usual: With much patience, in possession of the SWR meter, adjust roughly the height as indicated in the attached drawing, reaching about 3.95 m: the coil core.
The bridge of connection between the antenna connector and the coil of modified base, is connected with its clamp to about 2/3 of it, side mass.
This way as the original. All the antenna I have spaced about 80 cm. from the metal railing of my balcony, and here we may refer to the attached drawing for more specific details.
All indications suggest that it is obvious that they are indicative, and certainly those with experience on the development and installation of such antennas, know well how to operate.
The course will be a minimum of ROS by acting both on the length of the antenna, about moving the jumper on the roll of basic agreement.
I also suggest not to raise too much of the antenna from the balcony, with an orientation on the 80 cm. suggested, because, no lifting more than you gain a lot on the horizon, and you can create a problem basic agreement on the coil.
Hoping to have expressed a need, wish you good work and good DX.
Well... for what it is worth, I have reduced the length of the main radiating element but simply mounted the antenna on a fence pole (metal) just to see (rather hear) if there is anything out there to listen to.
For a giggle I tried keying the nominated operational repeaters in the Sydney area with no success.
But have had the mute open on various channels, but no intelligent life forms yet found!
Maybe in the coming weeks when my work-life slows down a bit I'll revisit this project & advise of my results.
Best CB antenna I have used on 50MHz is an Archer (Tandy/Radio Shack) three radial 5/8 Groundplane...leaves the Stationmaster and Ringo variants for dead, scarce as hens teeth now...Jack VK2XQ in Sydney.
Total length of antenna including coil 3950mm (approx)
First turn of the original coil was used with an OD of 205mm.
6mm OD aluminium tube used for coil.
This antenna was mounted with the coil 800mm about above a handrail.
The end fed antenna is a high impedance at the ends. In this case this is matched using a tunned circuit which is tapped so as to achieve the required transformation ratio from the 50 ohm feeder to the antenna impedance. For such a system to work properly it must be connected to a nominal counterpoise earth of at least 0.05 wavelength (mounting mast usually sufficient). The coil is resonated at the required frequency to achieve the match. The capacitance required for resonance is provided by the anenna base and the mounting plates for the coil.
An alternative to the coil matching system is to make use of a tapped quater wave coax stub. I have successfully converted a 10M Benelec endfed to this by replacing the coil by a tapped coax stub mounted in the space originally occupied by the coil. The results were much better than the original coil which was wound on lossy PVC conduit. I have used the same method to matched a full length 27MHz mobile whip mounted on a standard Australia HF mobile antenna base to function as a 6M half wave on my car. In this case the coax stub was shorter than the expected quarter wave (after allowing for velocity factor). This is attribute to the length of the antenna used and the capacity present in the HF base. In the short time I have had it, I have already managed to work DX on it with North coast of VK6 from Perth as well as to VK5.
There is an article of mine in VKlogger on the 6M coax matched half wave with more details.
To match the antenna using a coax stub you need coax, patience and some luck. In the case of the 6M mobile antenna, the first two bits of scrap coax I picked up of the bench provided an almost perfect match. I was not so lucky with the 10M one however.
An antenna analyser suitably interpreted will greatly assist in matching the antenna.
Mark, I looked up today (this afternoon) and what do I see... a ringo.
A dual band 10m/6m ringo.
I was going to take a photo of it for you, but since Dave VK2JDS owns it and he's on this forum (and sitting beside me) you can ask him for a picture or planes of it
Hi All... been thinking that the J-Pole style is the way to go.
Did it for my 2m/70cm dual band & that has given me more hype to have a go on a 6m version.
News at 11...
OK, this may well be the last post in this topic.
After thumbing through many diagrams, sketches & other on line sites, I bit the bullet (or should that be a PL259 ) & stripped down the 27mhz CB Ringo to form a J-Pole.
Construction was completed within a day & having some days off ( 'cause I work damn hard) the antenna is now up at about 5-6m above ground level (above the HF dipoles feed point).
V.S.W.R is very acceptable at 1.5:1 & 2 repeaters have been heard, VK2RWI @ Dural keyed & workable & VK2RBM @ Lawson(?) not keyed cause me thinks this repeater now has a 91.5Hz tone access. (I ain't got no tones... yet).
Oh and yes I heard the broadcast on Sunday morning on 52.525 from Dural, all be it very noisy PRIOR to the new elevation (today).
I'm up for a contact or two or three....
So far I'm leaving the box run on the VK2RWI repeater, then I'll move off to 52.525 for a simplex contact.
So call me if you dare! It's time to wake 6m up on FM.
Mark.
Here is pic of the antenna above the HF dipole feed point.
The tree is NOT mine but if it were, it'd have a bloody good hair cut!!
BTW the 2 straps to the top of the outrigger are non-metalic, they are made of plastic orange tongue, between sheets of compressed particle flooring.
Very rugged & makes a good insulator!!
