Ropex Active Antenna - UK Vintage Radio Repair and Restoration Discussion Forum

Jolly 7 · 16th Apr 2018, 2:46 pm

Here is an active HF antenna that came without a power supply. The text printed on it says both shortwave and from 20 kHz to 160 MHz, which seems quite impressive. However, I have only tested it for MW and SW listening, using a homebuilt 12V power supply. Does anyone have experience of using this antenna and maybe a power supply to share a picture of ? It would be nice to know a little more about this antenna. It does seem quite sensitive, but background electrical noise is marring reception at times, even when mounted outdoors.

Jon_G4MDC · 16th Apr 2018, 7:32 pm

It is a puzzle - never seen one like it.
Suspect it could be some sort of vertical whip with an active preamp below.
It will do what it does.

I would probably put it on a non conducting pole, fed by coax with some kind of choke in the feed cable. (Noise isolation from below)

If it is good - enjoy. If not then increment last letter X>Y.

Please let us know how you get on.

Jolly 7 · 16th Apr 2018, 9:59 pm

I am using RG58 coax cable. Guess I will make a ferrite ring choke to try filter out some of the RFI. With the dry weather round the corner this is a good time to experiment with non waterproofed components, although propagation conditions for MW may have passed their peak with the arrival of spring.

HamishBoxer · 17th Apr 2018, 7:55 am

The only Ropex I found on Google was a 136Khz tx from 1999.

G8HQP Dave · 17th Apr 2018, 10:28 am

More pictures might help someone identify it. It could be a 'badge-engineered' item more commonly known under a different brand.

G3VKM_Roger · 17th Apr 2018, 12:33 pm

Quote:

Originally Posted by HamishBoxer

The only Ropex I found on Google was a 136Khz tx from 1999.

Beat me to it! I think I saw one or two of these antennas in use on small craft back in my seagoing days. Wasn't the TX made in Holland?

Cheers

Roger

Jolly 7 · 17th Apr 2018, 2:35 pm

Some more pictures.....

G8HQP Dave · 17th Apr 2018, 3:36 pm

Results of my Googling:
Ropex are (or were?) Dutch, but there seems to be almost nothing about them on the web. I found a French radio amateur asking for info on the DX-100 antenna some years ago - with no apparent answer. You could try asking Nevada, who sold their 136kHz transmitter in the UK.

dsergeant · 17th Apr 2018, 5:57 pm

Probably a commercial version of the PA0RDT whip antenna since that originated from Holland. Do a Google. And yes, I am aware of the Ropex 136kHz rig so probably the same firm.

HamishBoxer · 17th Apr 2018, 7:57 pm

No Roger,I do not know if indeed it was made in Holland.Think it was by a "G" call sign.

16th Apr 2018, 2:46 pm	#1
Jolly 7 Octode Join Date: Feb 2018 Location: Southampton, Hampshire, UK. Posts: 1,061	Ropex Active Antenna Here is an active HF antenna that came without a power supply. The text printed on it says both shortwave and from 20 kHz to 160 MHz, which seems quite impressive. However, I have only tested it for MW and SW listening, using a homebuilt 12V power supply. Does anyone have experience of using this antenna and maybe a power supply to share a picture of ? It would be nice to know a little more about this antenna. It does seem quite sensitive, but background electrical noise is marring reception at times, even when mounted outdoors. Attached Thumbnails

16th Apr 2018, 7:32 pm	#2
Jon_G4MDC Nonode Join Date: Nov 2015 Location: Welwyn Garden City, Hertfordshire, UK. Posts: 2,015	Re: Ropex Active Antenna It is a puzzle - never seen one like it. Suspect it could be some sort of vertical whip with an active preamp below. It will do what it does. I would probably put it on a non conducting pole, fed by coax with some kind of choke in the feed cable. (Noise isolation from below) If it is good - enjoy. If not then increment last letter X>Y. Please let us know how you get on. Last edited by Jon_G4MDC; 16th Apr 2018 at 7:38 pm.

16th Apr 2018, 9:59 pm	#3
Jolly 7 Octode Join Date: Feb 2018 Location: Southampton, Hampshire, UK. Posts: 1,061	Re: Ropex Active Antenna I am using RG58 coax cable. Guess I will make a ferrite ring choke to try filter out some of the RFI. With the dry weather round the corner this is a good time to experiment with non waterproofed components, although propagation conditions for MW may have passed their peak with the arrival of spring.

17th Apr 2018, 7:55 am	#4
HamishBoxer Dekatron Join Date: Aug 2007 Location: W.Butterwick, near Doncaster UK. Posts: 8,932	Re: Ropex Active Antenna The only Ropex I found on Google was a 136Khz tx from 1999. __________________ G8JET BVWS Archivist and Member V.M.A.R.S

17th Apr 2018, 10:28 am	#5
G8HQP Dave Rest in Peace Join Date: Sep 2008 Location: Solihull, West Midlands, UK. Posts: 4,872	Re: Ropex Active Antenna More pictures might help someone identify it. It could be a 'badge-engineered' item more commonly known under a different brand.

17th Apr 2018, 2:35 pm	#7
Jolly 7 Octode Join Date: Feb 2018 Location: Southampton, Hampshire, UK. Posts: 1,061	Re: Ropex Active Antenna Some more pictures..... Attached Thumbnails

17th Apr 2018, 3:36 pm	#8
G8HQP Dave Rest in Peace Join Date: Sep 2008 Location: Solihull, West Midlands, UK. Posts: 4,872	Re: Ropex Active Antenna Results of my Googling: Ropex are (or were?) Dutch, but there seems to be almost nothing about them on the web. I found a French radio amateur asking for info on the DX-100 antenna some years ago - with no apparent answer. You could try asking Nevada, who sold their 136kHz transmitter in the UK.

17th Apr 2018, 5:57 pm	#9
dsergeant Octode Join Date: Mar 2006 Location: Bracknell, Berkshire,UK. Posts: 1,172	Re: Ropex Active Antenna Probably a commercial version of the PA0RDT whip antenna since that originated from Holland. Do a Google. And yes, I am aware of the Ropex 136kHz rig so probably the same firm.

17th Apr 2018, 7:57 pm	#10
HamishBoxer Dekatron Join Date: Aug 2007 Location: W.Butterwick, near Doncaster UK. Posts: 8,932	Re: Ropex Active Antenna No Roger,I do not know if indeed it was made in Holland.Think it was by a "G" call sign. __________________ G8JET BVWS Archivist and Member V.M.A.R.S