UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > Specific Vintage Equipment > Vintage Amateur and Military Radio

Notices

Vintage Amateur and Military Radio Amateur/military receivers and transmitters, morse, and any other related vintage comms equipment.

Reply
 
Thread Tools
Old 6th Oct 2019, 9:30 am   #1
ORAWA01
Pentode
 
Join Date: Apr 2011
Location: Stirlingshire, UK.
Posts: 184
Default Top band 1.8Mhz antennas

I was tuning around the top band the other night, and wow, it was very busy. I heard DL, DF, DD, F, LY, UY, ON, IZ, IK, EA .... and some ssb nets.
It will get even better with the winter coming.
Do you use the top band? What antennas do you have / use?

What antenna would be good for the band especially in limited space of garden like mine about 20m x 20m?
ORAWA01 is offline   Reply With Quote
Old 6th Oct 2019, 9:42 am   #2
HamishBoxer
Dekatron
 
HamishBoxer's Avatar
 
Join Date: Aug 2007
Location: W.Butterwick, near Doncaster UK.
Posts: 6,951
Default Re: Top band 1.8Mhz antennas

I do use it as a RSGB news reader.I will be on tonight at 2130 1.990Mhz.

I am using a folded dipole at 30 feet, though not the best.
__________________
G8JET BVWS Member and V.M.A.R.S
HamishBoxer is offline   Reply With Quote
Old 6th Oct 2019, 10:36 am   #3
ORAWA01
Pentode
 
Join Date: Apr 2011
Location: Stirlingshire, UK.
Posts: 184
Default Re: Top band 1.8Mhz antennas

I will listen out for your transmission on the band tonight, and update with sig. report here.
ORAWA01 is offline   Reply With Quote
Old 6th Oct 2019, 11:23 am   #4
G3VKM_Roger
Heptode
 
G3VKM_Roger's Avatar
 
Join Date: Jun 2012
Location: Southeast Norfolk, UK.
Posts: 547
Default Re: Top band 1.8Mhz antennas

Quote:
Originally Posted by budkor22 View Post
What antenna would be good for the band especially in limited space of garden like mine about 20m x 20m?
I use a 100 ft end-fed wire here, with insulated Flexweave. Vertical section is about 24 ft and I have six 33ft radials in the lawn. My plot is slightly smaller than yours but I have a tolerant neighbour who lets me use a tree in his garden to hold the far end up.

I use an SGC Smartuner which is located in a separate shed about ten feet from the radio shack. That set-up works OK on an IC-746 but also on my vintage gear like a Codar AT5 and KW-160.

73

Roger/G3VKM
G3VKM_Roger is offline   Reply With Quote
Old 6th Oct 2019, 11:34 am   #5
G6Tanuki
Dekatron
 
G6Tanuki's Avatar
 
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 7,783
Default Re: Top band 1.8Mhz antennas

Get up as much wire as you can! Then end-feed it against a good earth (lots of buried wires, and/or anything else metal)

One trick worth trying - to help make the wire look more like a 1/4-wave (so you get a healthy RF current flowing in the outdoor radiating bit rather than merely circulating in the ATU) is to bring the far end down the support and then zig-zag-load it: the zig-zag wires only need to be separated by a few inches. Essentially you're 'folding up' the far end of the wire (the bit which carries little current so contributes little to the actual radiation).
G6Tanuki is offline   Reply With Quote
Old 6th Oct 2019, 1:01 pm   #6
G3PIJpeter
Pentode
 
Join Date: Nov 2011
Location: Chippenham, Wiltshire, UK.
Posts: 161
Default Re: Top band 1.8Mhz antennas

Quote:
Originally Posted by G6Tanuki View Post
Get up as much wire as you can! Then end-feed it against a good earth (lots of buried wires, and/or anything else metal)
Loaded counterpoises are a good substitues for buried earths - a good deal less work for the same or better efficiency (see Moxon's book). I run mine around fences and tune with a series switched inductor with variable capacitor (add a current meter to the counterpoise 'earth' lead and tune for max).

Quote:
Originally Posted by G6Tanuki View Post
... bring the far end down the support and then zig-zag-load it: the zig-zag wires only need to be separated by a few inches. Essentially you're 'folding up' the far end of the wire (the bit which carries little current so contributes little to the actual radiation).
That trick was first discovered pre-war with a short loft aerial for Top Band. Also, Pat Hawker raised the subject in the 1980s. I have attached copies of the two papers that he referenced.

Peter (G3PIJ)
Attached Files
File Type: pdf meander dipole.pdf (576.1 KB, 66 views)
File Type: pdf meandered line antennas.pdf (113.8 KB, 54 views)
G3PIJpeter is offline   Reply With Quote
Old 6th Oct 2019, 2:11 pm   #7
G6Tanuki
Dekatron
 
G6Tanuki's Avatar
 
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 7,783
Default Re: Top band 1.8Mhz antennas

Yes, the "meander loading" approach works - you'll see something similar (implemented on a PCB) used for the integrated antennas in cellphones, Wifi routers etc.

Another option for the OP would be a short loaded vertical - again, the 'loading' can be done not by the traditional coil-and-capacity-hat method but by making up an insulating frame to support a large-pitched flat-helix of wire.

This method reduces the peaky 'really-narrow-bandwidth' issue that generally arises with very short inductively-loaded antennas.
G6Tanuki is offline   Reply With Quote
Old 6th Oct 2019, 4:18 pm   #8
G3PIJpeter
Pentode
 
Join Date: Nov 2011
Location: Chippenham, Wiltshire, UK.
Posts: 161
Default Re: Top band 1.8Mhz antennas

Quote:
Originally Posted by G6Tanuki View Post
Yes, the "meander loading" approach works ....
Another option for the OP would be a short loaded vertical - again, the 'loading' can be done not by the traditional coil-and-capacity-hat method but by making up an insulating frame to support a large-pitched flat-helix of wire.
A development was the 'sardine can-opener' in Radcom 1980s or so - possibly Ian White 'In Practice' or else 'Eurotec' translated from Dutch or German. Basically folding up the top 50-60% of a quarter-wave (or longer) vertical to make a 'T' shaped aerial with a non-radiating horizontal top portion.

Peter (G3PIJ)
G3PIJpeter is offline   Reply With Quote
Old 6th Oct 2019, 8:22 pm   #9
Andrew2
Octode
 
Join Date: Mar 2010
Location: Dukinfield, Cheshire, UK.
Posts: 1,502
Default Re: Top band 1.8Mhz antennas

I use a 40 foot vertical 'roach pole' antenna, inductively loaded about 30 feet up. A small adjustment coil at the base allows me to put the resonant point anywhere within the band. The 'earth mat' as I optimistically call it is about 100 sq ft of sturdy wire netting buried in the garden.
It seems to work reasonably well when fed with 30 watts of SSB from my homebrew transceiver and helps keep our local 1963 kHz AM net alive too.
The section above the loading coil consists of four parallel wires in an attempt to provide a bit more top capacitance.

This aerial is for transmit only as receiving on it is very noisy, so I use a Wellbrook loop for that.

I've tried the 'spiral top' idea and it worked a bit better, but the physical loading on the roach pole made me a bit queasy.
Attached Thumbnails
Click image for larger version

Name:	TB vert1.jpg
Views:	73
Size:	7.4 KB
ID:	191406  
__________________
Andy G1HBE.

Last edited by Andrew2; 6th Oct 2019 at 8:27 pm.
Andrew2 is offline   Reply With Quote
Old 6th Oct 2019, 10:42 pm   #10
ORAWA01
Pentode
 
Join Date: Apr 2011
Location: Stirlingshire, UK.
Posts: 184
Default Re: Top band 1.8Mhz antennas

Quote:
Originally Posted by HamishBoxer View Post
I do use it as a RSGB news reader.I will be on tonight at 2130 1.990Mhz.

I am using a folded dipole at 30 feet, though not the best.
I was trying to listen to the freq at the time, but QRN was 59+10, so I could not hear any stations at all.

Last time when I was listening to the top band, it was between 12pm - 1am, and the band was quiet.

Tonight, using the same antenna = 40m long wire loop, and same radio, QRN and RFI level was so high. Too many people around this area must be running some sort of electric appliances around that time.
ORAWA01 is offline   Reply With Quote
Old 6th Oct 2019, 11:21 pm   #11
Bazz4CQJ
Nonode
 
Bazz4CQJ's Avatar
 
Join Date: Apr 2009
Location: Oxfordshire, UK.
Posts: 2,524
Default Re: Top band 1.8Mhz antennas

Quote:
Originally Posted by Andrew2 View Post
I use a 40 foot vertical 'roach pole' antenna, inductively loaded about 30 feet up. This aerial is for transmit only as receiving on it is very noisy, so I use a Wellbrook loop for that.
Mmm...when the "QRN is 59+10", a magloop may be the way forward on receive?

B
__________________
We know there are known unknowns. But there are unknown unknowns ones we don't know we don't know.
Bazz4CQJ is offline   Reply With Quote
Old 6th Oct 2019, 11:55 pm   #12
Andrew2
Octode
 
Join Date: Mar 2010
Location: Dukinfield, Cheshire, UK.
Posts: 1,502
Default Re: Top band 1.8Mhz antennas

Indeed Bazz. I've been plagued by local noise for years and after trying all the usual ideas I shelled out for an early Wellbrook 1530 loop. To say I was amazed is an understatement. Even with the loop indoors I saw a huge drop in noise levels. When it went outside on a rotator it was even better, and for the first time in years I could hear MW and Topband signals against a quiet background.
Since then I've made a number of loops including one for VLF, as the 1530 starts to drop off below ~30 kHz.
Attached Thumbnails
Click image for larger version

Name:	photo 7 small.jpg
Views:	61
Size:	91.1 KB
ID:	191418  
__________________
Andy G1HBE.
Andrew2 is offline   Reply With Quote
Old 7th Oct 2019, 12:45 am   #13
Bazz4CQJ
Nonode
 
Bazz4CQJ's Avatar
 
Join Date: Apr 2009
Location: Oxfordshire, UK.
Posts: 2,524
Default Re: Top band 1.8Mhz antennas

Yes indeed, I built the "Wellgood" clone a few months ago and I've only tried it indoors on 80m, but found it worked very well. So, I'm heading in the same direction as you; planning to put up an inverted V for 80m later this month for transmitting, but expecting the magloop to beat it for reception. The noise level here on "wire antennas" is around S8, so only quite local stations will get through that.

B
__________________
We know there are known unknowns. But there are unknown unknowns ones we don't know we don't know.
Bazz4CQJ is offline   Reply With Quote
Old 7th Oct 2019, 7:47 am   #14
ORAWA01
Pentode
 
Join Date: Apr 2011
Location: Stirlingshire, UK.
Posts: 184
Default Re: Top band 1.8Mhz antennas

QRN cleared off at 11:30pm, and the band was quiet and I heard many SSB rag chewing stations.

Also I heard F6ARC working USA stations on 1.830 Mhz CW. I could not hear any US stations.

https://www.qrz.com/db/F6ARC
ORAWA01 is offline   Reply With Quote
Old 7th Oct 2019, 8:20 am   #15
HamishBoxer
Dekatron
 
HamishBoxer's Avatar
 
Join Date: Aug 2007
Location: W.Butterwick, near Doncaster UK.
Posts: 6,951
Default Re: Top band 1.8Mhz antennas

Well,I got into GM land last with Jim GM4NTL hearing me ok ,(another RSGB reader).

Still intend to try a couple of other options at this end though with the aerial set up.
__________________
G8JET BVWS Member and V.M.A.R.S
HamishBoxer is offline   Reply With Quote
Old 7th Oct 2019, 8:48 am   #16
ORAWA01
Pentode
 
Join Date: Apr 2011
Location: Stirlingshire, UK.
Posts: 184
Default Re: Top band 1.8Mhz antennas

Quote:
Originally Posted by HamishBoxer View Post
Well,I got into GM land last with Jim GM4NTL hearing me ok ,(another RSGB reader).

Still intend to try a couple of other options at this end though with the aerial set up.
The QRN here must have been purely locally generated one, as it is quite densely populated residential area.
ORAWA01 is offline   Reply With Quote
Old 7th Oct 2019, 10:11 am   #17
HamishBoxer
Dekatron
 
HamishBoxer's Avatar
 
Join Date: Aug 2007
Location: W.Butterwick, near Doncaster UK.
Posts: 6,951
Default Re: Top band 1.8Mhz antennas

I am afraid it is a major problem noise and not sure what is the answer.
__________________
G8JET BVWS Member and V.M.A.R.S
HamishBoxer is offline   Reply With Quote
Old 7th Oct 2019, 11:34 am   #18
AndyWright
Triode
 
Join Date: Feb 2012
Location: Bishop Auckland, County Durham, UK.
Posts: 33
Default Re: Top band 1.8Mhz antennas

I use a 150' inverted L here for 160 and 80m matched with a homebrew remote controlled L network. The L has a 35 ft vertical section. This has given me over 100 countries on topband including VK.

For receiver I use a K9AY loop which offers much better signal to noise than the transmit antenna. There are some picture on my QRZ home page.

Andy G4OJY
AndyWright is offline   Reply With Quote
Old 7th Oct 2019, 12:38 pm   #19
GW3OQK Andrew
Pentode
 
GW3OQK Andrew's Avatar
 
Join Date: Apr 2011
Location: Swansea, Wales, UK.
Posts: 119
Default Re: Top band 1.8Mhz antennas

Inverted L always seems most practical for the band. 10m up and 20m across with a tuner at the base would work OK.

I notice some use QRN for locally generated interference instead of QRM. QRN means natural atmospherics.
73
Andrew
GW3OQK Andrew is offline   Reply With Quote
Old 7th Oct 2019, 12:50 pm   #20
ORAWA01
Pentode
 
Join Date: Apr 2011
Location: Stirlingshire, UK.
Posts: 184
Default Re: Top band 1.8Mhz antennas

Quote:
Originally Posted by GW3OQK Andrew View Post
Inverted L always seems most practical for the band. 10m up and 20m across with a tuner at the base would work OK.

I notice some use QRN for locally generated interference instead of QRM. QRN means natural atmospherics.
73
Andrew
Thanks for the correction.
I used to think QRN meant static noise both natural and man made.

I should have said RFI.?
ORAWA01 is offline   Reply With Quote
Reply

Thread Tools



All times are GMT +1. The time now is 5:33 am.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Copyright ©2002 - 2019, Paul Stenning.