Can I add length to coax with adapters without causing problems?

[Lo/Dx Frontier]

I just ordered my radio setup. I chose a President Johnny III radio and a K40 model K30 antenna. I realized after I bought the antenna that the coax length is only 15 feet. I think this might end up 2-3 feet short to reach the radio. To me the simple solution is to add a double ended SO-239 adapter and a 3 foot jumper to finish it out. But will this “joint” cause any problems with introduced interference, or will there be any losses to be concerned with?

Also if I add coax, will it matter if the jumper I’m using is a better grade of coax than the long lead on the antenna? Say RG8X vs RG58?

 

[secret squirrel]

Adding the 3 feet to accommodate the needed length should not have any effect on your signal at all provided than you tune the antenna properly. Best of luck.

 

[Crawdad]

Any connections added will add some amount of loss, but @ 27MHz and lower power levels the amount is small and probably not noticeable.
As long as the coax you add is of the same impedance rating (50 ohm) it will be fine.
Having said that, a single un-spliced run of RG-8X would be a great choice.

7 3

 

[groundwire]

Under most circumstances it wont have any adverse effects. Its not desirable but it will work no problem most times. Just do it and find out for yourself. A few dollars, big deal.

 

[Lo/Dx Frontier]

I managed to find a 3 foot jumper available with a PL-259 on one end and an SO-239 on the other, so that will simplify things if I have to use it. As for the type of coax, I’m limited to whatever the K30 antenna comes with, which I think is just RG58. I hope it will reach. I want the antenna square in the center of the cab roof, but if it has to slide back towards the rear some in order to give me two more feet of length, then it will be ok. Worst case is the propagation is projected forward more, which will be just fine for my needs (highway use) and it would also look better on the truck I think. I’m gonna just wait and see how it goes.

 

[1KT001]

Come unire due spezzoni di cavo coassiale giunture coax senza bocchettoni barilotti .

 

[Captain Kilowatt]

I managed to find a 3 foot jumper available with a PL-259 on one end and an SO-239 on the other, so that will simplify things if I have to use it. As for the type of coax, I’m limited to whatever the K30 antenna comes with, which I think is just RG58.

No you are not limited to whatever came with the antenna. As long as both cables are 50 ohms you can join them. One could be RG-58 and the other half inch heliax........makes no difference. My station uses RG-8X patch cords into Belden 8214 then into Andrews LDF4-50 heliax then into more Belden 8214 at the antenna end. All 50 ohms......three different types of cable......all working in harmony as it should.