# 49MHz Rtl\_sdr receiver

**URL:** <https://www.ruby-forum.com/t/49mhz-rtl-sdr-receiver/246313>\
**Category:** GNU Radio\
**Created:** [September 26, 2013, 7:45pm UTC](https://www.ruby-forum.com/t/49mhz-rtl-sdr-receiver/246313 "2013-09-26T19:45:46Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Rafa\_F](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/958977/32.png) [@Rafa\_F](https://www.ruby-forum.com/u/Rafa_F)\
**Post date:** [September 26, 2013, 7:45pm UTC](https://www.ruby-forum.com/t/49mhz-rtl-sdr-receiver/246313/1 "2013-09-26T19:45:46Z")

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Hello list;

I have been following a thread by Marcus and others about coherent  
receivers, etc.

I have a question: Is it possible to change the clock frequency to  
receive a  
slightly lower frequency?

I have some ~ 49.89MHz wireless mic’s that I would like to reuse, and an  
SDR  
seems like a cool solution.

My current RTL dongle bottoms out at exactly 50MHz L Can I just change  
the  
clock or are their firmware issues as well?

Right now if a try and set the frequency to say 45MHz, I get a “device  
not  
found” error from the Windoze software.

Thanks;

Bill

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**Author:** ![casper\_the\_ghost](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/58956e/32.png) [@casper\_the\_ghost](https://www.ruby-forum.com/u/casper_the_ghost)\
**Post date:** [September 27, 2013, 2:02pm UTC](https://www.ruby-forum.com/t/49mhz-rtl-sdr-receiver/246313/2 "2013-09-27T14:02:37Z")

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On Thu, Sep 26, 2013 at 7:44 PM, William Pretty Security  
[removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote:

> My current RTL dongle bottoms out at exactly 50MHz L Can I just change the  
> clock or are their firmware issues as well?
> 
> Right now if a try and set the frequency to say 45MHz, I get a device not  
> found error from the Windoze software.

The clock has nothing to do with the RF range (not directly anyway)  
since there is an integrated tuner that converts the RF to DC or a low  
IF. Thew exact RF range depends on the tuner and if you get a device  
with the R820T tuner it will work down to 24 MHz or so.

Alex

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**Author:** ![casper\_the\_ghost](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/58956e/32.png) [@casper\_the\_ghost](https://www.ruby-forum.com/u/casper_the_ghost)\
**Post date:** [September 27, 2013, 2:04pm UTC](https://www.ruby-forum.com/t/49mhz-rtl-sdr-receiver/246313/3 "2013-09-27T14:04:23Z")

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The simplest solution might be to transvert using something like the  
ham-it-up. When not doing wireless mic duty, you’ll also have a general  
coverage receiver to tinker with.

Kindest regards,  
Ashworth Payne