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Thread: Radio station at 151.8 MHz

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    Default Radio station at 151.8 MHz

    There is a foreign language radio station that I would like to pick up that is transmitting at 151.80MHz. As normal FM radios receive between 87.5 and 108 MHz, it would not be possible to use one of these. I have contemplated a scanner/ VHF radio, but for the amount of use, I can't see myself spending hundreds of dollars. Is there anyway to "step up" the frequency of a std radio to achieve this? I remember years ago there were adaptors that you could attach to the aerial input of a Japanese impoted car, that would allow the receiver to receive radio in the correct spectrum - could something like this, or some other ad - on be employed to achieve a similar result with a "cheapie" fm radio?



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    Quote Originally Posted by JK200SX View Post
    There is a foreign language radio station that I would like to pick up that is transmitting at 151.80MHz. As normal FM radios receive between 87.5 and 108 MHz, it would not be possible to use one of these. I have contemplated a scanner/ VHF radio, but for the amount of use, I can't see myself spending hundreds of dollars. Is there anyway to "step up" the frequency of a std radio to achieve this? I remember years ago there were adaptors that you could attach to the aerial input of a Japanese impoted car, that would allow the receiver to receive radio in the correct spectrum - could something like this, or some other ad - on be employed to achieve a similar result with a "cheapie" fm radio?
    G'Day,
    This is not exactly what you are after, but there is a chance that it could be modified to suit your purpose.


    Description: Unit is inserted in the FM antennal lead and converts Australian/UK or USA FM band of 94-108MHz to Japanese FM band of 76-90MHz. E.g. a radio station at 104.3MHz will appear at 86.3MHz. 24VDC model available.
    AND
    Description: Unit is inserted in FM antenna path so that Japanese radios can tune Aus/UK/USA/Worldband broadcasts. Several models to choose from for covering FM bands in specific areas (since necessary compromises in the design of all FM converters will leave some frequencies untunable)
    Also make sure to read this.
    http://www.edl.co.nz/ConvertersHP/how-to-select.htm

    It will all depend on what you are prepared to pay for a one off unit.

    Kindest Regards, " The Druid ".

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    These transmissions - which are also in Adelaide with several services apparent - are in Narrow Band FM, so your standard FM broadcast receiver will recover very little audio.

    Any cheap 'scanner' will receive these signals and you have the choice of handhelds or 240V AC-powered units. Running continuous speech or music will flatten the small battery packs in handheld receivers quite quickly.

    Another alternative is the tiny and cheap eBay two-way handhelds, but they have a small speaker and still have the relatively short battery life problem. These radios transmit - which can be disabled - and cost only around $50 to $100.

    One more alternative is a (used, cheap) VHF highband mobile transceiver which will require a 13.8VDC power supply but will have much better audio with several Watts audio output, and will drive a speaker to high volume and fill a house. You can find many such radios quite cheap on eBay, but a modern mobile transceiver will need programming..

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    Quote Originally Posted by bulbous View Post
    Another alternative is the tiny and cheap eBay two-way handhelds, but they have a small speaker and still have the relatively short battery life problem. These radios transmit - which can be disabled - and cost only around $50 to $100.

    ..
    Thanks guys, can you describe the abovementioned device a little further, or provide an online link to one?

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    Yes, plenty of cheapy scanners out there for ~$50 with WBFM mode that can be used.
    You'll find them on VKHAM or Radiocorner.

    You can also make a converter for the job.
    SBL-1 is a mixer in a chip, but you can use almost any kind of diode or ring mixer.


    The LO frequency you want is about 50MHz.

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    Quote Originally Posted by trash View Post
    Yes, plenty of cheapy scanners out there for ~$50 with WBFM mode that can be used.
    You'll find them on VKHAM or Radiocorner.

    You can also make a converter for the job.
    SBL-1 is a mixer in a chip, but you can use almost any kind of diode or ring mixer.


    The LO frequency you want is about 50MHz.

    Sorry to be a pain, but is it a radio, tranceiver or scanner that I'm after?

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    For 240VAC (house) use you want a basic scanner, have a look on eBay and post what you find, someone here will advise on suitability.

    You need a basic 'scanner' - it doesn't need to have WBFM because it's NBFM you need. Something like this...



    or this handheld which you could probably leave on charge whilst it's in use...



    The desktop scanners usually have more audio power available and an external speaker can be plugged in. You will not like the sound of music through a poxy little handheld's 2 inch speaker. Some handhelds have an external speaker socket, but they have only a tiny audio amplifier running off 5V - a desktop scanner will have a better audio amplifier running off 13.8VDC and will drive a decent speaker.

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    Is something like this suitable:


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    That radio has a transmitter which you will of course be tempted to transmit with. This is very naughty unless you hold an Amateur Radio Operator's Certificate, and then it can be used on certain portions of the band 144.000 to 148.000MHz. Although it is unlikely that you will be caught using the transmitter be warned the penalties are pretty severe, and nobody is allowed to talk to you either. If you transmit on certain frequencies you can cause interference to other legitimate services, it is not considered good form to block out an ambulance trying to receive a call to pick up your dying grandmother etc.

    That little toy radio will hear what you want but has the problem of limited battery life and a tiny gutless speaker designed for voice only, and will sound strangled and quite bad on music....it is a toy.

    A base scanner as suggested is a better choice and you won't be tempted to break Federal laws.

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    I thought they were WBFM bulbous ? They always seem rather distorted on NBFM. I do remember hearing one which sounds a bit like it was running inverted audio as a form of scrambling.

    Yeah sorry JK200SX. I consider spending $10 on parts and modifying a $5 FM radio for the task so that I have good audio quality a better choice than listening to the program though a scanner speaker.

    DIY has always been the fun part. Before commercial satellite receivers, we built them ourselves. When we wanted to decode EPAL, SCPC, FM^2, Videplex and Macrovision, we did it ourselves.

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    Yes, they can sound pretty bad...some idjit cranks up the audio at the toy mixing desk and flat-tops every sound. It will sound wide into any decent receiver with sharp filter skirts as it crashes the sides !

    One of the Adelaide transmitters on 152.125MHz is strong even 160km away as it runs 50W into a 2.1dBi vertical from close to the summit of Mount Lofty at 710m. This transmitter is so strong here I can use 60dB of 50Z pads and it quiets the rx.

    The average high-band base transmitter is not really suited to the sound of the qualities of the Bouzouki, but I assure you the dreadful sound indeed comes from ACMA designation 16K0F3E.

    BUT !!! A bit more reading finds another wider tx on 152.200MHz with an emission designator of 41K0F3E ! This may be the transmitter type you hear in Sydney and although its deviation is nothing like as wide as an FM broadcast station it will certainly be too wide for the average communications-type receiver. This is the only transmitter found with a wider-than-normal deviation here in Adelaide but things may be different in Sydney.The transmitters on the OP's original post frequency of 151.800MHz are all 16K0F3E, with additional conditions related to spurii of :-

    "Special Conditions

    An efficient cavity filter must be fitted between the transmitter and the antenna.

    When the transmitter is coupled to an antenna the level of all discrete spurious components caused by the transmitter & measured at the connection to the antenna must not exceed -30 DBM. Broadband noise floor of the transmitter measured at the same point must not exceed -47 DBM in a 16 kHz bandwidth for frequency offsets greater than 300 kHz from the transmit frequency."

    (Cut and pasted with thanks to the ACMA)

    These Special Conditions are not seen often.

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    Why is there an FM station using 151.8 MHz?

    Surely this frequency is being used as a studio link?

    If that's the case, then they must have a standard broadcast band frequency as their main - so it would make more sense to pick that up on a standard FM receiver.

    Or did I miss something here?

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    It's narrowcast ethnic stuff,, but I can't tell you why it's in the middle of the VHF highband commercial spectrum. It has no partner broadcast station and they certainly wouldn't use such a crap quality system as a link for such.

    Makes a reasonable VHF-DX propagation indicator however.

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    Quote Originally Posted by bulbous View Post
    Broadband noise floor of the transmitter measured at the same point must not exceed -47 DBM in a 16 kHz bandwidth for frequency offsets greater than 300 kHz from the transmit frequency."

    (Cut and pasted with thanks to the ACMA)

    These Special Conditions are not seen often.
    Not often seen that they are that low, or that some of these stations don't even meet the low standards ?

    I've never paid much attention to them, but I didn't think any of them carried stereo information. It wouldn't take me long to check. I'll hook up the spectrum analyser tonight and have a peek at the various carriers.

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