Nokia "TTRX" -
Tetra Transmitter / Receiver
430MHz Modulator and High
Power Amplifier (250W PEP)
Triple-Channel Receiver
Frequency Synthesiser
This item is a complete, high power 430MHz transmitter receiver for
"Tetra" digital radio. The unit contains the following sections:
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430MHz Power amplifier - 250W PEP output
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Quadrature (I/Q) modulator
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THREE complete receiver channels
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Frequency synthesiser
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DSP baseband
The power amplifier is a linear, broadband design, utilising the BLF521
(pre-driver), BFL544 (driver), and TWO BLF548's in the output stage. The
BLF548 is a push-pull 500MHz 150W (RF output) MOS device. The output stage
brings two together in a broadband quadrature design, which is optimised for
high linearity. Earlier stages of
the modulator/amplifier utilise the BFG135 and BFG541. Please see links
below to the manufacturers data for all 5 devices.
The modulator is based on the Minicircuits JSIQ-430-2 hybrid I/Q
modulator. This is an integrated I/Q modulator sub-system incorporating
the RF phase-shift network necessary for I/Q modulation, and operates directly
at the RF carrier frequency.
The receiver is a full triple-channel design, utilising the BFG541 at the
front end, a Trak MXR/1121 RF mixer, a 4-pole 45MHz crystal filter, SA612 active
second-mixer, and a ceramic filter.
The synthesiser module, which is based on 3 of the ubiquitous SA8025
controllers, produces the various local frequencies required by the transmitter
and receiver sections.
If DSP is your thing, there is an impressive looking digital board covered in
DSP's!
The unit is in good condition, possibly new, but some scuff marks from handling
and storage. We have stripped two units for investigation, and found the
internal parts were pristine.
Please note: We are unable to perform any tests on this item.
They are strictly "off the pile", and hence
offered "as-is".
For international buyers who wish to save on postage costs, we can supply the RF PCB ONLY. This makes a significant difference to the cost of postage.
Please enquire for details.
The winner will be supplied
with schematic diagrams of the PA and driver
amplifier sections (.pdf files).
Specifications:
- Frequency: 430MHz (broadband)
- Output power: 250W PEP
- Power supply (DC): 28V, 12V, 5V (maybe
others)
- Weight - complete: 7kg
- Weight - RF PCB: 0.5kg
Datasheets:
BLF548,
BLF544,
BLF521,
BFG135,
BFG541,
SA8025,
SA612A
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Complete unit, showing the deeply-finned heat sink.
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Rear view.
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Synthesiser module.
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The DSP baseband.
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DSP removed......
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...And RF board exposed.
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The 250W output stage.
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The driver and pre-driver.
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The receiver (triple channel)
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Close-up of one PA device.
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Close-up of driver device.
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Close-up of pre-driver.
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One of two 50R balance loads.
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One of the I/Q modulators, there are two!
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The Trak receiver mixer and LNA.
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A 45MHz 4-pole crystal filter.
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There are other bits too, here is an RMS-2 mixer.
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Another view of the wonderful 250W output stage.
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* IMPORTANT INFORMATION
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This auction
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This auction is for an item similar to that
shown above. The serial number supplied may not match that shown.
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UK delivery £16.
International postage costs vary, please enquire for
details.
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Terms of Sale
Our terms and conditions are shown in full at: www.abex.co.uk/sales/terms2.htm.
Please be aware of the following:-
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Payment
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Full cleared payment must be received
prior to dispatch (or collection) of any goods.
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We accept bank transfers, cheques, postal
orders, Paypal and cash (for items collected).
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Our preferred payment method is bank
transfer.
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Paypal - Paypal payments will be
accepted from VERIFIED accounts with CONFIRMED addresses
ONLY. Items paid by Paypal will be posted to the
confirmed account address ONLY, by insured and traceable
mail. Items paid by Paypal will not be available for
collection in person.
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Postage
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We usually post ONCE per week (normally
Thursdays, but this does vary).
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Items will be posted by Royal Mail "recorded
delivery" or by courier (at our discretion), depending upon the item size,
weight, value, and destination.
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A signature will be required at
the time of delivery.
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Quoted delivery charges include packing
and handling, and a contribution towards our local transport
costs.
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International
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International buyers are welcome unless
restrictions are specified above "This auction".
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Payment in UK Pounds, by Paypal or bank (wire) transfer
only.
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Bank (wire) transfers - a fee of £12 will
be added to cover international bank charges.
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International shipping is expensive.
Please check shipping rates AND payment
options before you bid.
Ask first:-
esales@abex.co.uk
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