# Blasted RFM69CW

**URL:** <https://community.openenergymonitor.org/t/blasted-rfm69cw/8114>\
**Category:** emonTx\
**Created:** [31 July 2018 03:46 UTC](https://community.openenergymonitor.org/t/blasted-rfm69cw/8114 "2018-07-31T03:46:11Z")\
**Posts on this page:** 1\
**Showing post:** 2

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**Author:** ![Bill.Thomson](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/bill.thomson/32/1834_2.png) [@Bill.Thomson](https://community.openenergymonitor.org/u/Bill.Thomson)\
**Post date:** [31 July 2018 10:54 UTC](https://community.openenergymonitor.org/t/blasted-rfm69cw/8114/2 "2018-07-31T10:54:36Z")

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> [@danbates](#):
>
> My radio module stopped working last night.  
> I’d set the output power to +13dB

Working into a mismatched load with the output set that high, the RFM69 module is easily damaged.

> [@danbates](#):
>
> I’m interested to know if having a longer antenna, full wave length for example, would limit the amount of power being reflected into the chip.

Quite the opposite actually.  
An end-fed full wave antenna exhibits a high impedance, as does an end-fed half-wave antenna.  
The RFM69 is designed to work into a 50 Ohm load, thus both would cause an _increase_ in reflected power.

The solution for a monopole is an end-fed quarter wave antenna with a ground plane.

More info, and how-to, here: [Improving RF signal strength emonTH emonTX - #16 by Paul](https://community.openenergymonitor.org/t/improving-rf-signal-strength-emonth-emontx/5318/16)

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