Upgrading to Discone...

barnicles

Does anyone know how to go about doing a discone for Alinco DJ-X3?

Looking at rocketradio.co.uk

barnicles

http://www.rocketradio.co.uk/scanner-discone-se-900-antenna-86-p.asp

What about this + RG213?

watty

Looks & sounds the buisness. Yes.

barnicles

What connectors do you need for connecting the RG213 to the discone and for connecting to Alinco Dj X3 and Uniden Bearcat 72xlt?

watty

Discones can come with socket for PL529 or N-Plug. The PL529 is more likely.

I'd put a PL529 on both ends of RG213. Fold back the braid so you screw plug onto cable and solder center. Soldering the braid is not simple, so use the folded back idea. Tape outdoor joints with the Satellite connector rubber (amalgamating) tape or rubber pipe repair tape.

Use a 1m length of RG58 or RG8 patch cord to 72XLT etc as the RG213 is too heavy.

Use adpators such as below
http://www.rocketradio.co.uk/pl259-to-bnc-adaptor-938-p.asp to radio

barnicles

What about the alinco?

watty

The Alinco needs BNC to SMA. Use the PL529 to BNC of the 72XLT.

http://www.maplin.co.uk/module.aspx?moduleno=32015


use this to connect heavy stiff RG213 to a short 1m PL529 RG8 or Mini8 or RG58 patch cable
http://www.maplin.co.uk/Module.aspx?ModuleNo=1622



Patch cable:
http://www.rocketradio.co.uk/mini-rg8-rg8x-patch-lead-10m-with-fitted-pl259-uhf-connectors-786-p.asp

barnicles

Can you make a list of what i need to get, watty?

Much apprecitaed,
I'll be putting the discone in the attic.

Thanks

watty

Attic a bad idea.
about 6dB to 18dB loss
Detunes discone badly.

barnicles

watty wrote: »

Attic a bad idea.
about 6dB to 18dB loss
Detunes discone badly.

Near a window?

It's my only option.

watty

Experiment

what about a small light pole clamped to window sill or frame and Discone on it?

Antenna

watty wrote: »

Attic a bad idea.
about 6dB to 18dB loss
Detunes discone badly.

If its hung in the clear (not near any wires/ metal objects) and no foil backed type insulation behind the roof tiles, attic may well prove OK for VHF, with little loss compared to outside.

An omnidirectional aerial isn't going to be 'detuned' as easily as a directional aerial by nearby objects anyway

Using it indoors even near a window is going to be less than attic for signals from most directions

If you are interested in UHF, outside and higher is more important, but attic may still be OK, depending on what you want to hear.

It will of course last 'forever' in the attic, no need to worry about weather damage.

I say the above for receiving. Barnicles, if you are going to be using it for amateur transmitting do put it outside, unless tiny power, you would be much more likely to have interference problems having it in the attic

watty

A discone or a colinear are both detuned more easily by nearby objects (capacitance) than a 1/4 wave.

More of an issue for transmitting.

barnicles

Won't be transmitting

It will be in the attic.

A list of what i need?

watty

25W or 50W soldering Iron
PL529 plug x 2 for RG213
RG213 cable or similar from attic to where you want radio(s)

Screw socket joint between two PL520 plugs
Mini8, RG58 or RG8 patch cable abouut 1m, PL529 both ends
Adaptor that takes PL529 and plugs onto BNC socket (for scanner with larger socket)
BNC to SMA adaptor to convert small radio socket to be a BNC.

And the discone!

Nylon builders orange cord or similar to suspend discone from main beam of attic. (leave at least 25cm gap between top rods of discone and roof.

Ideally at least 2m away from any other things in attic.

gerryk

Try to get RG8X (Mini8) instead of RG213. The loss figures are similar, and it's much easier to work with, lighter and more flexible.

watty

It's certainly lighter and easier to work with.

Have you links illustrating the loss of each?

(on my longer run to mast with 2m/70cm Colinear, I use LMR400 along the ground and then RG213 up the mast)

LMR400 is cheap easy to work with alternative to Heliax. Though not quite as good loss. Hacksaw, knife, file and two spanners fits the compression type waterproof N-Connectors.