Thanks Rod. I think your response most closely matches my recollection of the original aerial length.
I must make a note of it before I forget !😉

Made me look!

I have one old (20+ years) FM radio and use that on my trawler. The receiver antenna goes up the aft mast and does not stand out. The radio is a Hitec "Ranger 3" (pretty heavy transmitter). All the others are 2.4ghz.

Lew
Florida, USA

I hav the receiver out of my 27 MHz trawler & the wire antenna is 21" long which is what i sort of recall as being normal for 27, so I think you shud add approx 19".
72/75 is just a bit shorter. On my 75MHz fast electric 13" of it protrudes outside the hull, going up inside a hollow wand that looks like a drinking straw stuck into a water outlet nozzle thru the deck.

(I checked all my 27 & 75MHz transmitters & they all measure 28 to 32").

I’ve had model cars and motor bikes on 27Mhz with aerial lengths of 8 to 10 inches usually fed through a plastic tube to hold it vertical outside the vehicle.
It would be worth connecting it up to a servo and doing a range check

Hi as far as actual practice goes I usually fit a high quality (gold plated) connector on the end of the aerial so I can unplug it easily. This leaves the aerial in the boat secure and unobtrusive to the eye.

I do have 27 FM, but mostly AM and 40 Mhtz AM and FM,bit mainly FM. And crystals galore.

My reason for not going to 2.4 Ghtz is that I have radio for more boats than I can ever build, so all rx's are dedicated. But it is best to leave a note inside the boat as to what colour or number it is.
Roy

Hi as a regular user of 27Mhtz the usual length of the rx aerial is 30 inches, it is not critical just do not leave it in a screwed up bundle. I make sure that 10 inches or so is vertical.
I check that all is working with the Tx aerial only partially extended.

The main advantage the 27 and 40 Mhtz have is you can poke your boat with the aerial. Not possible with 2.4Ghtz!

However do put a practice golf ball on the end to save others eyesight. You are supposed to have a frequency flag as well.

Roy

Looking this up on line and others have stated 14" to 40" but the manufacturers will have tuned the output to the length and type of wire used. Acoms sets are somewhat long in the tooth and were not the most reliable in my opinion. As most now use 2.4Ghz I doubt if there will be too much interference around on 27Mhz nowadays and I do recall it was common to add extra wire to the aerial without too many problems. I would suggest trying around 14" and doing a range check too see how far you can keep control. You could try speaking to a shop supplying Acoms sets and ask how long the aerial is on the Rx.
dave976