[McHUG] TX Modules Need Further Inspection

[Peter Morton]

Fell asleep in my Lazy Boy, woke up and wrote my first reply.  Shouldn't do 
that until I'm fully awake.  Anyway, it should be +/-150 KHz, not +/-75 KHz, 
deviation at 433 MHz with 2 volt peak-to-peak Vc input.

Also, in the second paragraph, it should state: The RFM02, not RFM01.  The 
RFM02 is a transmitter, RFM01 is a receiver.  (Both sell for $5.90 each.)

-Pete

----- Original Message ----- 
From: "Peter Morton" <mortonph at comcast.net>
To: "MicroController Ham User Group - Physical Computing for Ham Radio" 
<mchug at mailman.qth.net>; <pat at patkilroy.com>
Sent: Tuesday, December 23, 2008 1:25 AM
Subject: Re: [McHUG] TX Modules Need Further Inspection


> Just thinking.
>
> The Si571 can be frequency modulated.  The voltage control input has a 10 
> KHz bandwidth and the modulatation sensitivity can be set as high as 356 
> ppm/V (about +/-75 KHz at 433 MHz with 2 volt peak-to-peak Vc input). 
> You'll need about 15 dB gain following the Si571 to get 10 mW to the 
> antenna (and harmonic filtering, of course).
>
> I assume you want FM in order to run packet.  If you can get away with 
> FSK,
> Hope RF (Beijing) makes a number of 433.92 MHz FSK transmitter modules 
> (see http://www.hoperf.com/rf_fsk.asp).  Futurlec sells these modules. 
> See: http://www.futurlec.com/Radio.shtml.  (The RFM01 sells for $5.90.)
>
> -Pete
>
> ----- Original Message ----- 
> From: n3sb at qis.net
> To: <pat at patkilroy.com>; "MicroController Ham User Group - Physical 
> Computing for Ham Radio" <mchug at mailman.qth.net>
> Sent: Monday, December 22, 2008 9:17 PM
> Subject: Re: [McHUG] TX Modules Need Further Inspection
>
>
> Hi Pat;
>
> The module I got from you appears to be a TX433B.
>
> These modules are really designed for On-Off Pulse modulation. We've been 
> lucky
> so far to get something out of them that can be heard on an FM receiver. 
> It
> would be nice to get FM out of one of these. That's one thing that needs 
> to be
> looked at further.
>
> Have a safe trip in 8-Land, and Happy Holidays!
>
> 73; Steve, N3SB
>
> Quoting Pat Kilroy <pat at patkilroy.com>:
>
>> Hi Steve,
>>
>> I more than loaned you the module, forgive me
>> for the poor communication.  Consider it yours.
>> But remind me *which* module or modules you have ...
>>
>> The TX433 is the flea power unit, 10mW output max.
>> The TX433B module features 500mW but of course it
>> comes with a "more battery" mass requirement.  (I
>> always loved Rich's brilliant "double coin cell"
>> idea in the original PICetSat module, so I won't
>> give up on the smaller transmitter.)
>>
>> The B version also adds an extra pin, the E/D Pin,
>> to Enable and Disable the xmtr itself or the audio
>> input pin.
>>
>> Transmitter Web page:
>> http://store.qkits.com/moreinfo.cfm/TX433B
>>
>> MAIN POINT
>> I will give you, Rich and Pete either one or both
>> types before I head to Eight Land for the holidays
>> if you think you may have time to experiment with
>> them and learn more about them.  After all, the
>> spec sheet is lacking and customer support does
>> not seem to exist.  We need more insight on these
>> little devices!
>>
>> Guys, please let me know what you think of my
>> offer.  I must get them to you soon.
>>
>> Cheers,
>>
>> Pat
>>
>> > -----Original Message-----
>> [snip]
>> >
>> > Hi Pat;
>> >
>> > I have a couple TX-433 modules - one of which is a module you lent to 
>> > me a
>> > couple months ago. It'll be interesting to see if these modules can be
>> coaxed
>> > to send packet tones.
>> >
>> > 73; Steve, N3SB
>> >
>>
>>
>>
>>
>>
>>
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>
>
>
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