Just by chance I was doing a Google image search on VSWR circuits when I came across the following from PY2OHH. This design is not easy to find on the web so I thought I would share it with you here. In most cases I only build the reveres power side of the circuit as this is the parameter I'm normally interested in. I can assure you it works very well indeed, even with a 1mA FSD meter. However, It does tend only runs out of puff on Top Band where it requires the full 5W to get a meter indication, all the other bands up to ten meters works fine down to 1W.
I plumped for the coiled strip-line version and used a germanium point contact diode, similar to a OA81 device to get the best sensitivity. The design is simplicity itself with no complicated coupling transformers, plus its really easy to align.
The link below takes you to an English version of the design. Miguel is experiencing some issues with his web material so I've copied his design to my Google drive.
PY20HH Design on my Google Drive
Picture from PY2OHH project notes.