HF technical

[Slowboat35]

My boat has an insulated backstay for a HF radio.
The transmitter is long gone but an ATU (antenna tuning unit) remains
I am planning to use the antenna for a HF reciever only (for weather fax mainly)
Is the ATU in circuit with the antenna going to be a problem with my weatherfax reception, or would I do better to remove/isolate it fron the system?
Reciever is a NASA Target HF150

 

[Skylark]

The main purpose of an ATU is to present a tuned load to the transmitter stage of the radio. Reception is also likely to be better with signals from a 50 ohm load.

Most boat HF sets use automatic ATUs and these need an input signal from the transmitter. With practice and experience, a manual ATU can be tuned to improve received signal but I imagine that most HF receivers would be fine with your insulated backstay alone.

 

[Motor_Sailor]

Yes the standard marine ATU is an automatic unit that requires a control signal from the transmitter.

So it won't help in your set up. But depending on what it is and condition, it does have value. So remove it carefully!