Splicing a radar cable - how difficult?

[mike-m]

Have just bought a second hand Furuno radar set, a 1621 mark 2 with LCD screen. Unfortunately, the cable to the radome was cut while the set was being removed. Is it a major job to splice these cables?

It has a very fine coaxial cable inside the wiring bundle and I have been advised to join this with a TNC connector as they are the smallest and therefore neatest. Does anyone in Northern Ireland know where I can pick one of these TNC connectors up? Maplins and other electronics/aerial shops don't seem to have them....

Or would I be better just handing it over to a specialist??!! Any suggestions from the Norn Iron brigade?

Many thanks....

Mike

[Channel Ribs]

Originally Posted by mike-m

Unfortunately, the cable to the radome was cut while the set was being removed.

In my humble experience you sir are buggered.

It is possible to join RADAR cable, but you will I think do well to get hold of an all new one. Hopefully the price you paid reflected the lack of a good cable?

[JABS]

You can buy all sorts of connectors from RS Components, online.

Use solder and adhesive lined heat shrink. There is no reason why it shouldn't work. Hopefully, he cut it at a point where the join will be indoors.

It will be a long job. Plan it carefully otherwise the bundle will get very thick!

Good luck!

Might be worth a trial run on some cable that doesn't matter.

[codprawn]

Not done it on RADAR but I have spliced plenty of microwave links and satellite cables in my time.

They say you have to have expensive connectors and it is a hard job but I found just twisting the wires together did the job - if you want to be posh you can even solder them!!! I used kitcat foil for the shielding........

[biffer]

before you do anything have a word with geoffs on here, what he doesn't know about electronics i could write on my finger nail

[geoffs]

If you solder and heatshrink all the wires, making sure you connect both the inner and outer of the screened cables then overwrap the lot with self amalgamating tape then you should be fine.

No need for a connector unless you want to be able to remove the scanner regularly.

[mike-m]

Thanks everyone,

Will give it a go - must admit it is only the coax screened cable that worries me. Guess you just twist the centre wire together, solder and insulate, then crimp the screening and insulate?

Will let you know how I get on....

Regards

Mike

[jwalker]

Mike, before you start do a search. Joining screened cable and splicing radar lead has been covered before in reasonable detail.

[GJ0KYZ]

Radar operates at a ultra high radio frequency. This means that poor cable connections are very 'lossy' in terms of transmitted and received signal strength. One short circuit by way of a braid filiment touching the inner coax conductor will push your voltage standing wave ratio off the scale and may well damage the set beyond repair. You can try BNC connectors if you want (buy them from Waters and Stanton -01702 206835) but they're tricky to put on and if not done properly you will suffer signal degradation. My advice would be to return the set to the factory and get the job done professionally.

[ashbypower]

Originally Posted by GJ0KYZ

Radar operates at a ultra high radio frequency. This means that poor cable connections are very 'lossy' in terms of transmitted and received signal strength. One short circuit by way of a braid filiment touching the inner coax conductor will push your voltage standing wave ratio off the scale and may well damage the set beyond repair. You can try BNC connectors if you want (buy them from Waters and Stanton -01702 206835) but they're tricky to put on and if not done properly you will suffer signal degradation. My advice would be to return the set to the factory and get the job done professionally.

I agree fully with what you say, however not 100% certain but I think you'll find the UHF is confined to the scanner head and the coax being discussed carries a lower frequency/power signal.

G6YUX