How many urls do you want...
....? Which small walkman type radio? I generally don't play where there is a question on whether the cameras are on, but there are possibilities during construction that cannot be overlooked. The Palace Station after that lightening strike recently was one. I used a GPX analog walkman with cassette player with the bass boost switch attached to an extra coil across the am antenna rod. In THIS SPECIFIC RADIO it was 3 and 1/2 turns arround an about 1/4 inch ferrite rod, and signal at a dial position of 1430 am.
For any SW out of Flavor Radio type mod, add 455 khz to the dial frequency, multiply that by the likely harmonic of the local oscilator of the am section, and subtract then 455 khz, to get the target frequency.
You might aim for the actual frequency of the color burst crystal etc. too. This should cover the camera on detection.
During the expansion of the video poker area of AZ Charlies West, one of the contruction workers, independant of me, used a similar setup, homebrewing his own, to test which cammeras were on, to avoid having to reopen the bubbles etc., to see the "red leds."
Are you a Griffin Goon to have not known that this type of RF detection is so well known??? No one except a Griffin Geek would suspect too anyone having a walkman with them in the casinos.
A favorite site is Harry's Homebrew, which has about 8 urls it can be reached at. There are some experimental circuits at amasci.com listings that are good for this as well.