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[AlanB]

Hi,

Looking for some advice on the correct type of crystals for this radio set.

The Transmitter is a Hitec Laser 6  FM 40Mhz
The Receiver is a Hitec HFD-08RD - other info Dual Conversion, Ultra Narrow Band, FM.

I have a pair of crystals, but they don't seem to work.

Any ideas on the correct crystal type for this setup eg AM, FM etc ?

Thanks

[Doc]

AlanB,
The crystals you have may be the correct ones for the particular 'brand' that they are used in.  The tricky part is that not all 'brands'/manufaturors use the same parameters for their systems.  There are more than just one 'way' to determine frequency in a radio.  I have no idea about 'Hitec' or 'Futaba's requirements for 40 Mhz so can't really help, sorry 'bout that...
 - 'Doc

[justboatonic]

From the info you give on the Tx and Rx, both appear to be frequency modulated ie FM. Basically you can't use FM crystals in an amplitude modulated (AM) Tx and Rx set nor AM crystals in an FM set.

If both the Tx and Rx crystals are for FM Tx and Rx, are they both for the same channel? Its possible (but unlikely) a mismatched pair have been supplied. Note that the frequency often stated on the Tx and Rx crystal will be different.

If the Rx was bought separate to the Tx, then I'd suspect the Tx and Rx aren't compatible possibly due to the Rx being 'ultra narrow band.'

[Welsh_Druid]

 You say the RX is a Hitec HFD-08RD? - this is a DUAL CONVERSION RX as you state. These require a DUAL CONVERSION CRYSTAL.

? Are you sure the RX crystal you have IS a Dual Conversion crystal ?

[AlanB]

Thanks for all the replies.

Problem is now solved by taking the Tx, Rx, batteries and all to Scoonies and
making the request, Please fix this out.

Two crystals later a working set.

[White Ensign]

Alan, I have a Hitec as well and the chrystals from Graupner work perfectly in mine.

Happy modeling,
J?rg

[cbr900]

I have a GWS radio and a Hi-Tec Dual conversion receiver, works perfectly but you must use duasl conversion crystals..

Roy