SIGMA antennas for 43 MHz

From what I can tell, there are two main companies making antennas for the Italian 43 MHz CB market... SIRIO and SIGMA ANTENNE.

At the moment, SIGMA have three models...

GP 43
This is a basic quarter wave ground plane. Note that the gain is quoted as 2.5 dB but that is probably dBi as opposed to dBd.

BALCONY 43
This is very much a compromise antenna and is aimed at those with restricted space. It is probably slightly directional in the direction of the small radials.

TURBO 43
This is the five-eight wave ground plane and is made for 43 MHz. It's not obvious if there is enough tubing for it to made long enough to get down to 41 MHz.

The 1:1.5 VSWR bandwidth is claimed to be 1.64 MHz at 43.440 MHz.

At the slightly lower frequency of 42.0 MHz, it might be roughly 1.6 MHz which is pretty similar to the SIRIO model with 1.4 MHz bandwidth.

I suspect that like the SIRIO, the smaller GP43 might be better in terms of surviving high winds and for general listening around the low part of the VHF spectrum (30-50 MHz).

SIRIO Quarter Wave Ground Plane Antenna for 40 MHz

While it is pretty easy to build an antenna for 40 MHz, the difficulties of mechanical strength and waterproofing are always a problem. Some may considering buying a commercial antenna and this is an example of one from SIRIO.

The SIRIO GPA is a basic quarter wave ground plane antenna and there are several models available to cover various frequency ranges.

GPA 27-45: 27 … 45 MHz Tunable
GPA 40-70: 40 … 70 MHz Tunable
GPA 66-108: 66 … 108 MHz Tunable
GPA 108-136: 108 … 136 MHz Tunable
GPA 135-175: 135 … 175 MHz Tunable
GPA 170-230: 170 … 230 MHz Tunable

As there are no loading coils, it's just a case of adjusting the length of the vertical radiating element and each of the three ground plane radials.

ZETAGI power amps for 43 MHz

ZETAGI is a brand usually associated with CB radio products for 27 MHz although it seems that they also make RF power amplifiers for Italian CB band at 43 MHz.

The B149 and B129 models are shown below. Note that the Irish regulations for 30 to 49 MHz stipulate a maximum power output of 50 watts PEP.

ZETAGI B149

This is designed for 42-44 MHz and runs off 12v DC. It's likely that it will work down to 40 MHz as well although the power may be slightly reduced.

Note the AM / SSB switch on the right is missing and is just a blank plate. It would seem as if this unit is very similar to the B150 27 MHz model and uses pretty much the same hardware for the B149 43 MHz model.

The B149 amplifier is intended for increasing the output power of 43 MHz FM transceivers so there is no need for a TX/RX delay to stop the relay clattering on SSB. As such, it is not suitable for SSB and is more suited for just FM and CW.

ZETAGI B129

Example of Italian CB signals heard at 43 MHz...

The video clip above shows an example of a signal heard on the south-east coast of England of  a 43.3 MHz signal from Italy.

The CB band at 43 MHz in Italy is more of a 'working band' as opposed to the hobbyist nature of the band at say 27 MHz.

There is a short discussion about Italian 43 MHz radio on this forum.

It would also seem that the band is used is used to relay church services in Italy to elderly members of the public at home. Video of 43.575 MHz signal below. In Ireland, this is usually done on the 27 MHz CB band although some churches have been known to use 88-108 MHz!

Italian CB allocation at 43 MHz...

I came across a piece on the web today about an Italian CB allocation at 43 MHz. This is especially relevant considering that the proposed 8 metre radio amateur band in Ireland will go from 40.0 to 44.0 MHz.

The graphic above is from a 2012 brochure from Intek. A close up of the mobile is shown below...

International Versions... Note there seems to be an 'International Version' with 224 channels! With 12.5 kHz spacing, that's about 2.8 MHz of spectrum and it seems to cover 42.300-45.0875 MHz. The power o/p has been increased from 4w to 20w.

List of 43 MHz CB radios... Alan HM-43 4 W, Dragon MX-430 4 W, Intek K-43 4 W, Intek SY-343 4 W, Intek SY-5430M 4 W, Layayette ULTILITY

Wikipedia... Here is some info from Wikipedia...

Italy has a "VHF CB" allocation at 43 MHz, usually called "Apparati a 43 MHz" or "CB 43 MHz". 

Italy, like many other countries, suffers from extremely lax enforcement of radio communications laws, and "freeband" modified equipment covering wider frequency ranges as well as amplifiers are widely available and openly advertised by communications equipment vendors. "Freebanding" occurs with both the 27 MHz area (often as low as 25 MHz and as high as 30 MHz) and the 43 MHz area (as 43 MHz CB equipment is often modified to cover down to 34 MHz and up to 47 MHz, using 12.5 kHz steps). There is evidence of these frequencies being used outside of Italy for illegal "CB-like" operations.

Italian 43 MHz "VHF CB" or "43 MHz CB" allocation. 24 channels, FM mode, 12.5 kHz channel spacing. Each channel has a "recommended use" associated with it. Portable handheld (walkie-talkie), in-vehicle mobile and base station transceivers are available for this band. Channels are numbered in straight sequence, however many transceivers marketed for this band also include a frequency display. Due to the low-VHF band frequency characteristics of this band, it is often used as an adjunct to, or replacement for, the traditional 26–27 MHz CB allocations.

CH - FREQ - USE
1 - 43.3000 MHz – Rescue, Road/Traffic Control, Forestry, Hunting, Fishing, Security
2 - 43.3125 MHz – Rescue, Road/Traffic Control, Forestry, Hunting, Fishing, Security
3 - 43.3250 MHz – Rescue, Road/Traffic Control, Forestry, Hunting, Fishing, Security
4 - 43.3375 MHz – Rescue, Road/Traffic Control, Forestry, Hunting, Fishing, Security
5 - 43.3500 MHz – Rescue, Road/Traffic Control, Forestry, Hunting, Fishing, Security
6 - 43.3625 MHz – Rescue, Road/Traffic Control, Forestry, Hunting, Fishing, Security
7 - 43.3750 MHz – Industrial, Commercial, Agricultural, Crafts
8 - 43.3875 MHz – Industrial, Commercial, Agricultural, Crafts
9 - 43.4000 MHz – Industrial, Commercial, Agricultural, Crafts
10 - 43.4125 MHz – Industrial, Commercial, Agricultural, Crafts
11 - 43.4250 MHz – Industrial, Commercial, Agricultural, Crafts
12 - 43.4375 MHz – Industrial, Commercial, Agricultural, Crafts
13 - 43.4500 MHz – For safety of life at sea, Marine Use (Ship-to-Ship/Ship-to-Shore), Marinas and Harbors
14 - 43.4625 MHz – For safety of life at sea, Marine Use (Ship-to-Ship/Ship-to-Shore), Marinas and Harbors
15 - 43.4750 MHz – For safety of life at sea, Marine Use (Ship-to-Ship/Ship-to-Shore), Marinas and Harbors
16 - 43.4875 MHz – For safety of life at sea, Marine Use (Ship-to-Ship/Ship-to-Shore), Marinas and Harbors
17 - 43.5000 MHz – To aid in the administration of sports and other competitive activities
18 - 43.5125 MHz – To aid in the administration of sports and other competitive activities
19 - 43.5250 MHz – To aid in the administration of sports and other competitive activities
20 - 43.5375 MHz – to aid in the administration of sports and other competitive activities
21 - 43.5500 MHz – For use by health professionals, doctors, hospitals, and activities related to them.
22 - 43.5625 MHz – For use by health professionals, doctors, hospitals, and activities related to them.
23 - 43.5750 MHz – For use by health professionals, doctors, hospitals, and activities related to them.
24 - 43.5875 MHz – For use by health professionals, doctors, hospitals, and activities related to them.