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What is this antenna?

Phones- Digital, Analogue, PABX, Receivers, transmitters & military equipment.
 
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Re: What is this antenna?

Post by Michael Watterson » Fri May 31, 2013 10:20 am

Mobile Radio, e.g. Taxi or Tetra?

Looks like a loading/matching coil at base and they are specifying minimum area of metal to set it on. It may be electrically 5/8ths wavelength, so perhaps Mobile licence (even Tetra) between 400MHz and 470MHz.

Could even be for licensed OB link (microphone etc, Radio interview in car etc) at bottom of UHF TV band.

 
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Re: What is this antenna?

Post by DavidW » Fri May 31, 2013 11:25 am

Looks like part of the additional "car kit" that went with the very early BT cellphones. The ones with handset that had push buttons on the back and clipped on the cars transmission tunnel. The works lived in a holder in the boot and could be removed to carry about as a portable!
When I first became a manager I was entrusted with one which,as I recall,was next to useless!

 
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Re: What is this antenna?

Post by Refugee » Fri May 31, 2013 11:27 am

I was about to say that it is a very old phone antenna from one of the briefcase type analogue units.
The mid 1980s ones had something that looked more like a rubber duck. I would go for early 1980s.

 
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Re: What is this antenna?

Post by DavidW » Fri May 31, 2013 11:35 am

80s would be about right. We occasionally used to leave a set with customers who were going to be out of service at important times,like christmas. Service coverage was usually hopeless,compared with what we all take for granted nowadays.
Last edited by DavidW on Fri May 31, 2013 11:36 am, edited 1 time in total.

 
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Re: What is this antenna?

Post by Michael Watterson » Fri May 31, 2013 11:35 am

Yes. Even 450MHz ish is possible for Analogue Mobile. Since GSM 900MHz (872 to 960 band) was allocated and ran in parallel for a while with Analogue Mobile, Analogue Mobile surely must have been elsewhere. It seems large for 900MHz band anyway, but not impossible. The UK ETACS (Vodafone anyway) seems to have used most of the GSM band, so ETACS and GSM must have interleaved channels.
http://en.wikipedia.org/wiki/ETACS
But I'm pretty sure Wikipedia is lacking info / inaccurate on UK Analogue Mobile.

GSM uses 200KHz Duplex channels and TDMA (time slots for each connection/call) with GMSK modulation for voice (max 14.4kbps data). For later "EDGE" high speed data multiple time slots (245kbps = 0.245Mbps), variable QAM and last EDGE development was multiple channels (up to 2.4Mbps, not implemented in UK/Ireland)

NMT analogue Mobile was on 450MHz, very good Rural coverage. (Nordic Mobile Telecom?)
http://en.wikipedia.org/wiki/NMT_450

C-Netz 450MHz Analogue Mobile in Germany
http://en.wikipedia.org/wiki/C-Netz

If it was 450MHz, it will likely work for 430MHz to 440MHz Amateur usage. Tetra on 450MHz band is recent and replaces earlier Analogue allocations.

 
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Re: What is this antenna?

Post by Michael Watterson » Fri May 31, 2013 11:36 am

DavidW wrote:80s would be about right. We occasionally used to leave a set with customers who were going to be out of service at important times,like christmas. They were next to useless,compared with what we all take for granted nowadays.


Due to lack of base stations!


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