Thursday, 26 June 2014


One of the challenges of the CHOTA station is that in order to have live maps of WSPR spots, I need an internet connection. I could use my phone as a Wifi hotspot, but the GSM/GPRS signal is almost none existant at the church. The local pub is about 200m away and has free wifi, but its out of range.

What you see in the photo is a low cost, far east, WiFi repeater! I took a punt on this device, with the fear that it would use a single PCB mounted antenna, which would prevent its modification for greater range. When it arrived, my second worry was that its two pin mains connection, which I simply will not trust to be safe, would go to a SMPSU which would be on a single PCB with the repeater circuitry.

My fears seem unfounded. On opening the box up, I find that the SMPSU is on its own board, and simply feeds 5V DC to the main circuitry. Excellent - remove that and add a 7805 regulator, and it will run off a 12v 7Ahr SLAB. Also to my great relief and pleasure, it has two antennas - connected by coax!

The plan is to replace the antennas with coax sockets, and use external WiFi antennas (I already have a 2.4GHz Yagi), add the regulator and SLAB (Sealed Lead Acid Battery), put it all in a box, with a handle, and hey presto! A transportable WiFi repeater node!

I have yet to test the unit, and its always a bit hit and miss with these far east made cheap gadgets. I'll report back its performance later.

The extra 300 ohm window line has also arrived. This means I can finish the feeder section of the ZS6BKW antenna, and also make another 2m Slim Jim. I intent putting this one inside the radome of a defunct Jaybeam colinear that I have kicking about the workshop.


Andres Sandoval said...

How do you identify the input and output antenna. ?
Because I'm looking for put the input antenna outside my home to maximize the neighbors wifi

Zak The Rabbit said...

I havent as yet. Its something I need to work on when I next play with the system