rrees
New member
I am looking for a combined aerial does anyone know of one and the breakout unit to split to the 2 units
Thanks
Richard
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Thanks
Richard
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VHF Mobile Phone Aerial
- Thread starter rrees
- Start date
G
Guest
Guest
I don't know if this is the proper way to do it, but a few years ago I split my standard aerial cable by cutting the very end and fitting a standard t.v aerial connector and used a "Y" connector from Dixons. I found that as long as I kept the two seperate ends fairly short (I cut 4 foot off the aerial for the splitter, and three foot of cable to either unit), I didn't lose signal at all.
p.s If you do join two units like this, you can only turn one on at a time or you could damage the other unit when you transmit.
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p.s If you do join two units like this, you can only turn one on at a time or you could damage the other unit when you transmit.
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wooslehunter
Active member
I'm not sure what specific gear is around for this application but I can explain the principles and why the correct gear should be used rather than Dixons TV connectors and a split cable. There's nothing wrong with them when they're used in a TV antenna setup of course.
An antenna is a tuned system that looks electrically like a 50 ohm resistor at the tuned frequency. Therefore a transmitter will see the antenna as a resistor. Since it's designed to put maximum power into a 50 ohm resistor it's happy. Antenna cables and connectors have what's known as a characteristic impedance and this is also 50 ohms in the case of marine VHF systems.
If you play around with the cable or connectors, the radio no longer sees 50 ohms. This results in some of the power being bounced back into the radio by the antenna / cable. This can make it hot and bothered. Since TV cables are 75 ohm cables, even putting a TV connector in the cable can cause problems. Having said this if you have both phone and VHF on the same cable and it fails you lose both.
If you want to use the same cable for VHF and mobile then have a look round for the proper equipment. Hopefully someone will add to this thread and advise since I'd like to know what's around as well.
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An antenna is a tuned system that looks electrically like a 50 ohm resistor at the tuned frequency. Therefore a transmitter will see the antenna as a resistor. Since it's designed to put maximum power into a 50 ohm resistor it's happy. Antenna cables and connectors have what's known as a characteristic impedance and this is also 50 ohms in the case of marine VHF systems.
If you play around with the cable or connectors, the radio no longer sees 50 ohms. This results in some of the power being bounced back into the radio by the antenna / cable. This can make it hot and bothered. Since TV cables are 75 ohm cables, even putting a TV connector in the cable can cause problems. Having said this if you have both phone and VHF on the same cable and it fails you lose both.
If you want to use the same cable for VHF and mobile then have a look round for the proper equipment. Hopefully someone will add to this thread and advise since I'd like to know what's around as well.
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poggy
New member
Hi,
TV aerial cable is 50ohm, video signal cable is 75ohm. The key reason you shouldn't do this is that a mobile phone is a completely different frequency to a marine VHF, therefore it will be very inefficient for a mobile phone and probably provide a worse signal than the internal aerial on a portable mobile. Also as a mobile is continuously seeking a base station and exchanging data it would intefere with the VHF reception. Have you ever put you mobile next to your normal phone at home and listened to the interference.
You can buy marine mobile phone aerials to be mounted on the mast, but you do have to have a seperation between the VHF aerial. The best solution would be to pick up a proper car phone which has a SIM card slot, as these have a higher output than using a car kit with a normal mobile phone slot. Make sure it is unlocked from the network so you can use your existing SIM card.
Good luck
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TV aerial cable is 50ohm, video signal cable is 75ohm. The key reason you shouldn't do this is that a mobile phone is a completely different frequency to a marine VHF, therefore it will be very inefficient for a mobile phone and probably provide a worse signal than the internal aerial on a portable mobile. Also as a mobile is continuously seeking a base station and exchanging data it would intefere with the VHF reception. Have you ever put you mobile next to your normal phone at home and listened to the interference.
You can buy marine mobile phone aerials to be mounted on the mast, but you do have to have a seperation between the VHF aerial. The best solution would be to pick up a proper car phone which has a SIM card slot, as these have a higher output than using a car kit with a normal mobile phone slot. Make sure it is unlocked from the network so you can use your existing SIM card.
Good luck
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rrees
New member
Car Kit is the approved nokia model
after hearing from the group I think I will stick to seperate cables
What seperation should I have between the aerials
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after hearing from the group I think I will stick to seperate cables
What seperation should I have between the aerials
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poggy
New member
I am not an expert on mobiles, but I think that a height seperation would be best due to the transmission pattern of both bits of kit.
Can you mount it lower down the mast or to the rear somehow.
Poggy
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Can you mount it lower down the mast or to the rear somehow.
Poggy
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