Tom Bruhns wrote:

So if you have 200 feet of RG-213 and 200 feet of RG-58, put those in
series to the cantenna. Coil them loosely and cool them with a fan if
needed, if you are running high power (or start the chain with larger
coax). . .

One thing to keep in mind when you use coax as an attenuator or dummy
load is that the portion of the cable nearest the transmitter dissipates
most of the power. If you had, say, 6 dB per 100 ft attenuation and a
200 ft cable, the first 50 ft dissipate 1/2 the power (and that's
concentrated toward the transmitter end), the next 50 ft dissipate 1/4
the power, the next 50 ft 1/8, and the final 50 ft 1/16. So do as Tom
says and put the heavier coax up front, and allow for more air
circulation for the coax nearest the transmitter if dissipation becomes
a problem.

Roy Lewallen, W7EL