Another numpty question?

[jb2006]

We have a radar reflector, but, if it is switched on, will our radome produce a more powerful active paint in the x band frequency? Or would that only happen if our 4 degree scan band was exactly in synch with another vessels receiver? or not at all?

 

[Twister_Ken]

Presuming you mean a radar, rather than a radar reflector, having your radar on won't do anything to help other vessels see you. OTOH, you should be able to see them.

Radar reflectors, except the SeaMe, are unpowered.

 

[jb2006]

No, I meant we have a radar reflector - I was wondering whether the radar scanner (radome) would also provide a signal detectable by other radar units in the same frequency band

 

[Twister_Ken]

The answer is still no. Your radar scanner is not designed to produce an echo when radar-illuminated.

 

[Dyflin]

Actually the answer is yes, but...

AFAIK, as the radar sweeps through the frequencies it will once in a very blue moon receive on the same frequency that you are transmitting. TBH, the odds are better for you to win the lottery, but I have seen it on a very small number of occasions.

It will paint a very unusual pattern on the screen and will in no way identify your boat any better at all.

 

[Topcat47]

Actually the answer is No. It's not Impossible, but it is highly improbable.

Radar's do not "sweep" a range of frequencies, they transmit and recieve the same frequency, but in order not to swamp the Reciever, the reciever is "switched off" when the pulse is transmitted and "switched on" "later" (we are taking microseconds here) when the pulse has travelled beyond the originating vessel. The Reciever then amplifies any returned signal for display, however there are filters to prevent the Rx from responding to a signal which is too strong. Arguably a smallboat radar pulse at a distance might well fall inside the tolerence of the Big ship's radar reciever, but it would also need to be operating at the same frequency, directed down the throat of the antenna at precisely the right time to be detected. This would require some synchornisation of the two antennas (the small boats and the large ships) as well as the pulse repetition frequencies of the two radars.

We are now getting into "more chance of winning the lottery" realms of probability here.

Racon beacons are deliberatley designed to give a huge, elongated echo on incident Radars, this is not the case with your small boat radar (or even the Seeme transopnder)

 

[Dyflin]

I was getting mixed up with racons and their sweeping frequencies. /forums/images/graemlins/blush.gif

So really the answer is yes, it is possible, but extremely rare?

 

[Twister_Ken]

Isn't this all a load of old trousers?

You put your radar on, not so the other guy can see you, but so that you can see him.

 

[pvb]

[ QUOTE ]
Isn't this all a load of old trousers?

[/ QUOTE ]You haven't forgotten the purpose of these forums, have you? /forums/images/graemlins/wink.gif

 

[narooma]

Question. Does it do any long term damage to the set if used in the 'expanded' mode rather than normal reception?

 

[Daedelus]

You can see other radars operating. However, you need to turn the rejection control off in order to do so. As soon as you have done this the screen is covered with other radar signals from Heaven Knows where. (Curved dotted lines since you ask).

It might be useful if you were in (say) mid Atlantic and there was nothing else around, but since most will have the intereference rejection circuitry working it probably wouldn't do you any good there either.

You're small, read up the colregs as regards radar, and follow them.