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Re: Re: 2m to 70cm upconverter design, any interrest ??



Hi Endy

If you plan to use the KA9LNV transverter as a transmit converter for VO-52
from 435.225 to 435.275 MHz than the 101.875 MHz crystal is not suitable
with an IF 28 to 30 MHz because 101.875 x 4 = 407.500 MHz and
407.500 + 28 = 435.500 MHz

In place of it you should use a 101.750 MHz crystal because
101.750 x 4 = 407.000 MHz and 407.000 + 28 = 435.000 MHz so that
you can cover 435.0 to 437.0 MHz with an IF from 28 to 30 MHz

A good crystal manufacturer in USA is ICM and I suggest to contact this
people showing the schematic diagram of the circuit in wich the above
mentioned series resonant fifth overtone crystal must oscillate.

In any case the second part of the article published by K9LNV in QST
september 1991 covers in details the crystal-frequency selection and IF
interfacing.

73" de

i8CVS Domenico


----- Original Message -----
From: "Andy Brian" <briaandy@gmail.com>
To: "i8cvs" <domenico.i8cvs@tin.it>
Cc: "AMSAT-BB" <amsat-bb@amsat.org>
Sent: Saturday, June 25, 2005 10:58 PM
Subject: Re: [amsat-bb] Re: 2m to 70cm upconverter design, any interrest ??


> Hi,
>
>
> I know about that converter which was published in QST, the author was
> KA9LNV.
> The main problem for many of homebrewer were the local oscillator or
better the
> crystal 101.875MHz, the  problem was to get them somewhere.
> Maybe any suggestion to take any similar crystal?
>
>
> best regards Andy
>
> On 6/25/05, i8cvs <domenico.i8cvs@tin.it> wrote:
> > Hi Andy
> >
> > If you've been thinking of making the move up to the 70 cm learning
> > someting more about RF in the UHF field with inexpencive construction
> > and using your old HF 10 meters equipments than the 70 cm transverter
> > described by Ed Krome, WA9LNV in QST august 1991 and september
> > 1991 is a good way to do so.
> > Look at it in the QST cover
> > The above transverter with IF 28-30 MHz for in/out is designed to
> > be built dead-bug style on pieces of doubled-sided, unetched printed
> > circuit board and so no conventional PCB with striplines is required.
> > In addition inexpencive readily available MMIC and transistors are
> > used.
> > The above transverter is built in three different sections:
> > Xtal local oscillator
> > Receive converter
> > transmit converter
> > If one don't need it to receive than simply forget the receive converter
> > or vice versa
> > I am using it as a receiving converter and it works great.
> > To duplicate the above transverter is very easy because the Ed's article
> > explain everyting step by step and reading it is very informative.
> >
> > If any one like a copy of the above article I can send it by email.
> >
> > 73" de
> >
> > i8CVS Domenico
> >
> > ----- Original Message -----
> > From: "Andy Brian" <briaandy@gmail.com>
> > To: <amsat-bb@amsat.org>
> > Sent: Saturday, June 25, 2005 12:22 PM
> > Subject: [amsat-bb] Re: 2m to 70cm upconverter design, any interrest ??
> >
> >
> > > Hi,
> > >
> > >
> > > if you want to help with cheap and simple converter is the best choice
to
> > > publish this converter in plain format for homebrewers etc. circuit
> > > diagrams and PCB at your homepages
> > >
> > > because the electronical elements is inexpensive in Asia and some
others
> > > countries.
> > >
> > > This is my opinion, I know this is your hard job and you want to help
us,
> > > but I think this converter won't bring you money for your job.
> > >
> > >
> > > best regards Andy
> > > > >>-----Original Message-----
> > > > >>From: William Leijenaar <pe1rah@yahoo.com>
> > > > >>Sent: Jun 23, 2005 3:08 PM
> > > > >>To: amsat-bb@AMSAT.Org
> > > > >>Subject: [amsat-bb] 2m to 70cm upconverter design, any interrest
??
> > > > >>
> > > > >>Hi AMSATs,
> > > > >>
> > > > >>To get on the 70cm HAMSAT uplink is not easy for many
> > > > >>hams in the world. FM handies are available, but other
> > > > >>modes than FM is very rare and to expensive for those
> > > > >>hams.
> > > > >>
> > > > >>To get them on 70cm ssb the best way is to use an
> > > > >>upconverter from their widely available HF. With use
> > > > >>of an upconverter an 10m ssb signal will be converted
> > > > >>into an 70cm ssb signal and can be used for HAMSATs
> > > > >>uplink.
> > > > >>With use of a 2m to HF down-converter the same HF can
> > > > >>be used for receiving the HAMSATs ssb downlink.
> > > > >>
> > > > >>I have been looking around the web to find available
> > > > >>converters. For 2m to 10m down-converters there are
> > > > >>several options, with good prices. Unfortunatly for
> > > > >>10m to 70cm up-converters there is very little
> > > > >>available and with high prices.
> > > > >>
> > > > >>Because of this I have been working on a cheap and
> > > > >>simpel to make design. After some weeks testing and
> > > > >>experimenting I got something on the test bench.
> > > > >>
> > > > >>The prototype can be seen on my webpage:
> > > > >>www.qsl.net/pe1rah/10m70cm.htm
> > > > >>
> > > > >>or via my main page:
> > > > >>www.qsl.net/pe1rah
> > > > >>
> > > > >>The features of the design are:
> > > > >>-------------------------------
> > > > >>* Made on a PCB
> > > > >>* In a metal box (74mm x 148mm x 30mm)
> > > > >>* 407MHz local oscillator build in
> > > > >>* 12Vdc power supply
> > > > >>* 50mW output on 70cm (enough to drive M57716 10W
> > > > >>power module)
> > > > >>* 28MHz BNC input, 70cm BNC output
> > > > >>* Unwanted suppression >40dB
> > > > >>* No exotic components
> > > > >>
> > > > >>When there is enough interrest I will deliver kits and
> > > > >>complete constructed converters.
> > > > >>
> > > > >>I can not deliver it for a price less than below:
> > > > >>-------------------------------------------------
> > > > >>Kits              = 175 USD (+ shipping costs)
> > > > >>Complete build    = 250 USD (+ shipping costs)
> > > > >>
> > > > >>!!! Please note that this is a complete TX
> > > > >>upconverter, included PCB, Crystal, metal box, BNC
> > > > >>connectors etc etc
> > > > >>!!! The only thing needed to be qrv on HAMSAT 70cm
> > > > >>uplink is a final amplifier.
> > > > >>!!! Best solution is a M57716 module that give 10W
> > > > >>output at the 50mW input.
> > > > >>
> > > > >>Let me know if there is any interrest,
> > > > >>
> > > > >>73,
> > > > >>William Leijenaar
> > > > >>PE1RAH
> ----
> Sent via amsat-bb@amsat.org. Opinions expressed are those of the author.
> Not an AMSAT member? Join now to support the amateur satellite program!
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----
Sent via amsat-bb@amsat.org. Opinions expressed are those of the author.
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