Homebrewing a Sirio Gainmaster using RG58 and 2.5mm wire.

The place to talk about specific radios, equipment and accessories. Do you prefer the latest generation of rigs and antennas or do you like the classics? Discuss it here!
kamikazeandi
Regular
Regular
Posts: 9
Joined: 13 Jun 2013, 10:48

Re: Homebrewing a Sirio Gainmaster using RG58 and 2.5mm wire

Post by kamikazeandi » 28 Jun 2014, 18:18

Hello,
yesterday I was on the "Ham radio" for the first time and probably the last time! ;)
For me, the show was a little disappointing when you know big fairs like the "Aero" in Friedrichshafen, where I was this year also. The only interesting topics for me were the stand-alone full functionell 5W-SDR-TRX FDM DUO from Italy, with which one I could play, and a SDR-TRX-series from Russia, I did not know. The big 125W-SDR-TRX SunSDR-MB1 (160m to 2m - max 80MHz Panadapter) even has touch-screen (http://www.sunsdr.com/en/home.html). The transceiver makes a very good impression, but unfortunately for my wallet a little too cheap (3700 EUR). ;)
End "Off topic"!

The low-loss coax cable I did not get as much as some other things for other antenna projects. So I must now order coax cable.
OK, I'll start with 11 turns in the stub and test approach me. Thank you for your reply and the good idea, Psi.
Also, now a bit more work coming back into my job to me. So my new building of the gain master can take a little. But then I will report!
Regards,
Andi

Python
New User
New User
Posts: 3
Joined: 10 Sep 2014, 06:59

Re: Homebrewing a Sirio Gainmaster using RG58 and 2.5mm wire

Post by Python » 13 Sep 2014, 18:00

Hello from Finland, made a homebrew gm two weeks ago and im getting very good reports now compared to j-pole and slimjim antennas i have. Old friends ask me "what have you done to your equipment?" Stations that hardly heard me before tell im coming s3-5 or so. Conditions have been great this summer, wish i had this hbGm done earlier. Big thanks to you all who took part to this conversation and research.

Coaxial was Urm67 PE cable, it has same vf and capasitance as rg58, but attenuation is better. Like rg213, not the best but good enough. The cable is very stiff, so i made a coil of 5 turns on 105 mm plastic tube former. Coil is not axial with the pole, but on the side of it like a reel on the fishing pole, looks ridiculous ... works ok, no common modes. 5r on 105 mm has good reactance on cb band. Stiff cable was hard to work a good T-joint on the matching stub and lower radiator. Used a lot of black glue-sealant ( dont know what you call it in UK) on it to make it rigid. Its the stuff builders use when glueing things together, not silicone gasket thats too soft.

Dimension are a bit longer than in Psidocs original Gm: lower radiator 3.51 meters, upper is about 3.56 meter. Easy to adjust , cut off cable ties and roll the coil lower and you get longer lower, upper rad you can solder more wire " on the field" with cigarette lighter... so tested different lengths. Stub point dont change this way but maybe not big problem.

I suspect that when you glue thin wire on the glassfiber pole its electrical length , VF , changes, i mean it must be longer than in free space? Have noticed this some times with thin wire made antennas glued on poles, but not sure, so im asking if anyone have realized same thing or am i totally wrong or theres something else going on. SWR is now very good, 2 low points almost 1:1 and the CB band just midle of them 1:1,2. Maybe this upper length thing is not very important at all? What about radiation pattern with longer upper rad?

The best thing to do may be to make upper radiator of the same coax as lower and same length.
But anyway, these lengths work well on CB band based on reports from stations 30-100 km away.

73 to all, Python

vkrules
Regular
Regular
Posts: 38
Joined: 28 Sep 2013, 00:10
Call Sign: vk4aap

Re: Homebrewing a Sirio Gainmaster using RG58 and 2.5mm wire

Post by vkrules » 20 Sep 2014, 00:53

The ant is so broadband that slight differences in length wont make much difference it will just move the swr curve a little higher or lower. Anyway a little longer is better than a little shorter . Have a look at the ENZEC model posted earlier. As for the pole changing the length I haven't seen that . Pole is only on one side not surrounding the radiator so Vf shouldn't change significantly . Make sure you do not use carbon fiber pole . If you are unsure of poles construction , take a small scraping of fiber material and place in microwave oven for a few seconds, if it gets hot material is carbon.Changing the gauge of the wire will change the length .Have fun my gainmaster is still in use daily.

User avatar
slamjam
Radio Addict
Radio Addict
Posts: 677
Joined: 02 Nov 2010, 18:52
Call Sign: 26DT871
Location: Suffolk JO02

Re: Homebrewing a Sirio Gainmaster using RG58 and 2.5mm wire

Post by slamjam » 16 Oct 2014, 12:54

Hi any chance of some dimensions for a 15m version?
IC-756PRO - IC-756PRO 3 - FT-1000D Classic - FT-990 - Acom 1000 - TS-2000 - TS-790e 2/70/23cm- TS-850SAT + XV144 -Superstar 360FM - Galaxy Saturn 2 - Icom ICR1000

User avatar
bigpimp347
Legend
Legend
Posts: 8416
Joined: 08 Aug 2009, 10:23
Location: J26 Nottingham
Contact:

Re: Homebrewing a Sirio Gainmaster using RG58 and 2.5mm wire

Post by bigpimp347 » 28 Dec 2014, 19:57

a few pictures of the Gain Master naked :)

Coax to tuning stub.

Image


Image

top section coax capacitor.

Image

Image

certainly could have been lacquered or insulated better than just heat shrink tubing..
http://livecbradio.co.uk UK's only 24/7 live stream

User avatar
Irishman1127
Moderator
Moderator
Posts: 4444
Joined: 23 Jan 2011, 12:34
Call Sign: EI7KO
Location: Central Ireland

Re: Homebrewing a Sirio Gainmaster using RG58 and 2.5mm wire

Post by Irishman1127 » 28 Dec 2014, 20:02

Not what you'd expect for the money eh? mark...
CQ CQ CQ DX

User avatar
bigpimp347
Legend
Legend
Posts: 8416
Joined: 08 Aug 2009, 10:23
Location: J26 Nottingham
Contact:

Re: Homebrewing a Sirio Gainmaster using RG58 and 2.5mm wire

Post by bigpimp347 » 28 Dec 2014, 20:30

£120 for a couple of bits of coax and some wire..!!
oh and a poorly built up bit of fiberglass tube and a plant pot to use as a choke former..!!

terrible when you think about it..
http://livecbradio.co.uk UK's only 24/7 live stream

kamikazeandi
Regular
Regular
Posts: 9
Joined: 13 Jun 2013, 10:48

Re: Homebrewing a Sirio Gainmaster using RG58 and 2.5mm wire

Post by kamikazeandi » 07 Feb 2015, 01:17

PsiDOC wrote: .. I'd go with 11 turns at 100mm, if the swr starts acting strange - Shooting up quicker than you'd expect - at either end then unwrap half a turn and try again... Then unwrap andother half turn etc. You know the drill. But with 11 I think you'll be very close if not there.

Si
Hello PsiDOC,
long time ago. That's not so funny! Sorry for that!
Now I have build a new GM, completely with H2010 (vf=0.83), diameter 10.2mm with the following dimensions:
GainMaster H2010-2.png
I've started with 11 turns with a choke at 100mm diameter but not so happy with the SWR:
GM_H2010_vs_RG-213.jpg
I have used 2 different SWR-meters, the one in my FT-857D and an old Wipe 110, that is a bit more sensitivly.

The temperatures these days are not so friendly here in West-Germany, and for now, i will let the GM at the mast on the roof. But as soon as the temperatures will rise a bit, I'll climb up again and try 10 turns at the choke.

Or do you have a better idea? Maybe shorten the lengths? Cut the stub a bit?
Or maybe you see a big mistake in my calculations?

Andi
You do not have the required permissions to view the files attached to this post.

INTERCEPTOR
Regular
Regular
Posts: 46
Joined: 02 Nov 2014, 12:48
Call Sign: INTERCEPTOR

Re: Homebrewing a Sirio Gainmaster using RG58 and 2.5mm wire

Post by INTERCEPTOR » 02 Mar 2015, 18:09

kamikazeandi wrote: Can we extend this GainMaster to a broadband vertical SKYPPER for the 10m to 12m band?
Regards Andi
PsiDOC wrote:Andi,
RE: The skypper no that's not crazy. It'll be interesting to see if we can model it out to a 5/8 wave broadband antenna, although putting the Gainmaster on it's side does give you about 8 dbi in 2 directions on it's own. ;)

Si
I have read this thread but I don't full understand all the technical side really, but I was interested when I read the above quote.

Has anyone tried the antenna horizontal/flatside?

Is it as simple as mounting it horizontal and using it directionally? How does it perform? Would the SWR change?

Hopefully I will get the opportunity to try this antenna for myself soon once I learn more.

Thanks for taking the time to discuss this and for your time experimenting.
Image

sec1223
Top Poster
Top Poster
Posts: 1683
Joined: 28 May 2010, 09:28
Location: west yorkshire

Re: Homebrewing a Sirio Gainmaster using RG58 and 2.5mm wire

Post by sec1223 » 06 Mar 2015, 19:01

has anyone got a definitive build yet?.

iv read so many versions now its doing my tits in.
cant stand IGNORANT b******ds

INTERCEPTOR
Regular
Regular
Posts: 46
Joined: 02 Nov 2014, 12:48
Call Sign: INTERCEPTOR

Re: Homebrewing a Sirio Gainmaster using RG58 and 2.5mm wire

Post by INTERCEPTOR » 07 Mar 2015, 19:17

sec1223 wrote:has anyone got a definitive build yet?.

iv read so many versions now its doing my tits in.
I'm confident that if you follow PsiDOC's instructions on page 1 that you will have a perfectly operational antenna for 10/11 Meter band.

The discussion has,on the later pages, been about using the antenna on other bands.

What bands are you going to use?

Are you going to make this antenna?

I will be making one soon....once I have some time.

Please let me know if you make this antenna, I would like to know how you find it perform. :thumbup:
Image

User avatar
bigpimp347
Legend
Legend
Posts: 8416
Joined: 08 Aug 2009, 10:23
Location: J26 Nottingham
Contact:

Re: Homebrewing a Sirio Gainmaster using RG58 and 2.5mm wire

Post by bigpimp347 » 08 Mar 2015, 21:37

or just get a gain-master and dissect it and get all the measurements..
like i have, if i get time i'll do the write up to go with the pictures..
http://livecbradio.co.uk UK's only 24/7 live stream

User avatar
lambrettadave
Top Poster
Top Poster
Posts: 1400
Joined: 11 Apr 2011, 15:50
Location: sunderland

Re: Homebrewing a Sirio Gainmaster using RG58 and 2.5mm wire

Post by lambrettadave » 08 Mar 2015, 23:47

bigpimp347 wrote:or just get a gain-master and dissect it and get all the measurements..
like i have, if i get time i'll do the write up to go with the pictures..
I will enjoy reading that Mark
CALL SIGN 26TM455 OPERATOR DAVE QTH SUNDERLAND

http://www.flickr.com/photos/88011785@N06/ for CB magazine.reviews

http://www.youtube.com/user/lambrettadave7 for some vids of my radios.

DJT979
New User
New User
Posts: 3
Joined: 23 May 2015, 20:46
Call Sign: DJT979

Re: Homebrewing a Sirio Gainmaster using RG58 and 2.5mm wire.

Post by DJT979 » 23 May 2015, 23:11

Hallo, I can´t see the pictures from the first post, anybody saved them and would send them to me?
I like to homebrew this antenna for me here :D

Regards, Dennis

INTERCEPTOR
Regular
Regular
Posts: 46
Joined: 02 Nov 2014, 12:48
Call Sign: INTERCEPTOR

Re: Homebrewing a Sirio Gainmaster using RG58 and 2.5mm wire.

Post by INTERCEPTOR » 27 May 2015, 19:39

DJT979 wrote:Hallo, I can´t see the pictures from the first post, anybody saved them and would send them to me?
I like to homebrew this antenna for me here :D

Regards, Dennis
Dennis I printed some copies of the Pictures PsiDOC kindly created.

I have pictured them with my phone.

If you cant see anything on the picture ask and I will tell you what is says.

I have this antenna as my only home antenna and it seems to work ok. My SWR is about 1.6 on the UK 40 Channels FM AND ABOUT 1.2-1.3 on CEPT/MID BAND.

It was my first antenna build and I solder joined everything and used really thick RG213 coax for everything except top radiator which was a couple of pieces of wire soldered together! BUT IT WORKS! If it was made as well as others on here have done it is probably as good as any factory antenna (or better!)

Please let us know how it goes for you.


Image

Image[/quote]
Image

Post Reply

Who is online

Users browsing this forum: No registered users and 7 guests