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Date: | Wed, 9 Mar 2011 09:31:52 -0500 |
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one thing to consider is if you put ends on the coax and use a barrel you have a more versitile arrangement and you can use the cables for other purposes later. also splicing besides the impedance "not capacitance" problems make it a waste of time. and it is much less work to just install connectors.
73 kb7nla
On Mar 7, 2011, at 6:32 PM, colin McDonald wrote:
> I reflect the sentiment that, no, it isn't usually a good idea to splice
> coax unless you absolutely have to do it to get back on the air.
> If you do have to splice it, there are a few ways to do it so that it
> reduces the bump which will cause the coax to be off the 50Ohm capacitance
> rating at that point...when a coax doesn't have a consistance spacing
> between the center conducter and the shield, the rating alters which leads
> to standing waves at that point along the coax...heat, and other nasties.
> You need to splice the coax in a way that makes it as close to the original
> spacing and original diameter etc.
> I've been known to use tin foil to make the shield continuous in a splice.
> Of course the problem there is that you run into problems using different
> metals...changing from copper to alluminum back to copper...it introduces
> resistance into the coax that wasn't there before.
> One of the ways i've done it is to feed the multi-strand center conducter
> together so that it is the same size as the rest of the center conducter,
> Solder that connection point, then use small heat shrink tubing to seal and
> insulate the center conducter at the bear connection point...then slide the
> shield back over the heat shrink tubing until it's touching...drip solder
> over as much of that connection as possible, then wrap the beared portion of
> the shield with alluminum foil...then use the appropriate sized heat shrink
> tubing on the outside to seal and insulate the shield as well.
> This takes some pre thought and you have to cut the ends of the two pieces
> of coax so that you have enough of the shield to pull back over the center
> splice and electrically connect them together...also you need to cut the
> right lengths of heat shrink tubing to slip over the coax before you splice
> it.
> You can use electrical tape instead of heat shrink tubing as well...but it
> won't last as long.
> Though electrical tape has a better insulating factor, several KV per layer
> I think...so it would work better as a dialectric than heat shrink tubing
> might.
> best to go and buy a new chunk of coax with or without the ends you need in
> this situation.
> Especially if you are trying to splice RG58 type coax...that stuff is allot
> harder to splice than say RG8 style or 213, or 9913, or LMR 400 etc.
> 73
> Colin, V A6BKX
> ----- Original Message -----
> From: "Christopher Moore" <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Monday, March 07, 2011 2:27 PM
> Subject: splicing coax
>
>
>> Hello,
>> Is it a good idea to splice coax? I wouldn't consider it for an outdoor
>> run but what about indoors?
>>
>> Chris
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