[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]

R: SSB Electronic Transverter Crystal Sources?



Hi Alan WA4SCA,

Since OSCAR-10 i am using the model LSM-24 transmit converter wich
has the same oscillators with J310 but only 500 mW output.

In order to prevent direct interference in to the 145-146 MHz IF of my
converter corresponding to 2401-2402 MHz receiving AO40 i drive
the LSM-24 mixer only from 144 to 145 MHz both for the L1 and L2 bands.

I see that selecting a 93.667 MHz crystal you think to do the same !

For L2 band
93.667 x 12 = 1124 MHz additional cristal in Q1
1124 + 144 = 1268 MHz
1124 + 145 = 1269 MHz

For L1 band
93.750 x 12 = 1125 MHz original cristal in Q2
1125 + 144 = 1269 MHz
1125 + 145 = 1270 MHz

The type of oscillators Q1 and Q2  are FET Colpitts oscillators using
FET U310 or J310 and the cristals are series resonance normally 5ft
overtone.

The SSB Electronics supplied to me the above transmit converter with
the above cristals upon my order to be used for OSCAR-10 Mode-L and
those cristals comes from the german manufacturer KVG

Those cristals are very critical for a good stability in a Colpitts circuit
and i recommend to buy it from a manufacturer that normally  supply SSB
Electronics or KUNE (DB6NT)

I think that SSB Electronics or DB6NT should have no difficolty in supply to
you the above cristals because they normally uses this type of Colpitts FET
oscillators in all their converters except for 24 GHz and they are in
contact with KVG

Another source of the above cristals is the Eisch Electronic Ulm in Germany

Ordering the above cristals i suggest to you to send a photocopy of the
oscillator electric diagram.

If you like to improve the oscillators performance you should remove both
the 78L09 regulators wich became too hot and change it with the bigger 7809

I am very happy with this 500 mW transmit converter and i drive from it a 10
watt solid state linear amplifier and than from it a two tube 7289 cavity
amplifier antenna mounted for L1 and L2 bands on AO40

I hope this help a bit.

73" de i8CVS Domenico


----- Original Message -----
From: Alan P. Biddle <APBIDDLE@att.net>
To: AMSAT-BB <AMSAT-BB@AMSAT.Org>
Sent: Thursday, August 22, 2002 4:39 PM
Subject: [amsat-bb] SSB Electronic Transverter Crystal Sources?


> Hi,
>
> I have an SSB Electronic LT24S transmitting converter, left over from
AO-13.
> Identical to the LT23S, but without the receive section.  The operating
> range is 1269-1271 MHz for a 144-146 TX IF.  For full utility on AO-40, I
> need to shift this slightly to 1268-1270 MHz.  According to the
> documentation, it uses an HC-25/U series crystal, and of course the needed
> crystal (12X LO) is 93.667 MHz.  SSB is researching the matter, but of
> course this is an obsolete unit.
>
> This will need to be a custom crystal, and I am looking for recommendation
> for a source that from personal experience is reliable and affordable.   I
> have already done the Google search, so I don't need a raw vendor list.
>
> Alan
> WA4SCA
>
>
> -----------------------------------
>
> To get the attention of a large animal,
> be it an elephant or a country, it
> helps to know what part of it feels
> pain. Be very, very sure, though, that
> you want its full attention!
>
> ----
> Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
> To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org












----
Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org



AMSAT Top AMSAT Home