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All sold! A hearty Thank You to all rc-cam members that joined in on this special deal.

Hi Thomas, I am going through the calibration procedure with my RSSI meter and I have a problem. I'm using one of these receivers http://www.electronicarc.com/catalogo/product_info.php?cPath=43_49_70&products_id=454&osCsid=d00c2c9bd05e2cd4369b7d86592ab8c4

I have identified the RSSI pin of the Rx module and wired up a 3 wire servo lead with plug similar as the picture in the manual. I noticed that when I turned off my video Tx the RSSI LCD would appear to turn off (go blank, it probably doesn't turn off). I measured the voltage with my digital multimeter on the RSSI pin of the Rx module when my video Tx is turned off and it is 5.70v.

This is higher than what the manual specifies, could this be causing the RSSI LCD display to go blank?

Do you suppose this particular Rx I have is unsuitable to be used with the RSSI dislay?

Is there a work-around (resister in line) or other solution?

Thanks Geoff

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Be careful with RSSI signals that exceed 5.0V -- they will cause mischief and possibly damage the meter. So, always check for this before installing the meter.

The input to the meter is about 57K ohms. So, a series resistor can be added to form a simply voltage attenuator. A series 10K ohm will drop your 5.7V to ~4.85V, so try that (verify with a voltmeter after it is installed).

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Did the series 10K fix the problem?

Hi Thomas, I have fitted a 10K resister in series with the RSSI as you suggested and this has bought the voltage down to about 4.8v as predicted.

This allowed me to complete the calibration process and everything looks good now.

Thanks very much.

Geoff

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You are welcome; Glad the resistor solved the problem. Thanks for the update

I checked the tuners in several different wireless video Rx's and none had RSSI above 5.0VDC. But there are several dozen Chinese made Comtech'ish tuner clones out there and so anything is possible with their Shan Zhai designs. :)

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Hi Thomas,

Is it possible for me to 'mod' this to run from 5v (as opposed to the 7 - 14 v )

I want to use it on an R/C Rx to watch the RSSI and use a std servo connection (including the 5v supply).

I'm at work so can't check the voltages on my board, but better to ask first before hacking away.

Nigel.

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Is it possible for me to 'mod' this to run from 5v (as opposed to the 7 - 14 v )

If your RSSI signal does not exceed 3VDC you may be able to use the meter as-is. Otherwise, just unsolder the Vreg IC and apply clean external 5VDC in its place. Or replace the Vreg with an LDO type.

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If your RSSI signal does not exceed 3VDC you may be able to use the meter as-is. Otherwise, just unsolder the Vreg IC and apply clean external 5VDC in its place. Or replace the Vreg with an LDO type.

Thanks Thomas.

Still at work here :(

I think the RSSI signal is under 3v so will try as is (I'll check first).

If not, LDO Vreg it will be.

Nigel.

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I measure 3v3 at the Vreg output - correct?

Therefore, 5v input should be fine.

RSSI is ~2.7v max and the display seems to be working OK on a bench test.

Nigel.

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