So I thought I'd try out a wireless video camera on one of my tanks. Good fun, but the PAL cameras that are sold in the UK seem to be limited to 50mw - unlike the NTSC versions that output 200mw. As a consequence the range is pretty poor. I managed to get better coverage of my garden by using a scanner antenna that's up on our roof. At 1.2GHz it not perfect but better than the whip that came with the unit. One down-side to remote viewing - the Panzer eventually came home minus the outer half-of three of the top track rollers. I walked back over the routes I took but only managed to find one in the grass []

The camera came from here: http://www.paramountzone.com/microcam.htm

One thing that I'm a bit unhappy about is the photo on the website shows a different product to one they sent me. The photo on on the website shows a version that has a 4-way switch for 4 different RF channels. I wanted this so I could get another and run two video-equipped tanks for tele-combat. I wish online retailers would take more care when they display their items.

I dunno, I recall reading that the 200mW rating on the NTSC units is bogus and based upon the power consumption, not the actual transmission power! [>:]

D.

It's the dumb sort of thing they'd do... but I'm not sure. The spec that comes with them isn't very clear - it just lists the parameters for PAL and NTSC side by side and underneath it has 50mW 200mW. I read it as different power for Europe vs. US. With the measured current draw at around 60mA the whole unit consumes about half a Watt.

I just traced out the cct. and there's only two transistors, one I think (BC846) as an audio sub-carrier osc. and the other (2SC64226) as the UHF output osc. What are you like at RF design? It's not my strongest area. The emitter resistor for the output stage looked a bit high (220R) so I put in 100R instead. It seems to have increased the range a bit, but nothing dazzling. Maybe its the printed inductor in the collector load that determines the power - I'm not really sure. Can you believe they got this down to two transistors though! It would be nice to come up with a hack to get the range up to that of the Tank R/C

Sounds like your RF is better than mine. I'm better at digital.

This is where I found the reference to the output power being a bit of a stretch.

http://www.rc-cam.com/hk_video.htm

D.

Buy from ebay and get a 200mw version. I like the infrared ones myself. Much smaller too.