Damaged N-Type - Page 1
Forum section: electronics / rf-microwave

author: veedub565
author_rank: Frequent Contributor
timestamp: June 13, 2020, 04:43:22 pm
content: I bought a 2nd hand Diamond X-50N antenna for £40 plus £15 round trip in petrol to collect it ( so £55 all in). 6 months old, never been used for TX, still had the bag and fittings. Was being sold in a local(ish) ham radio buy/sell/swap group.Paid cash, got it home and found the N-Type connector to be damaged. I'd be surprised if it ever worked properly in that condition (picture attached)I contacted the seller, but no response. Even if they do agree to a refund, which I doubt. It's another round trip to take it back and £30 out of pocket in petrol then with nothing to show for it.Question is, can it be saved? The petals haven't snapped Assuming they bend back without snapping (doubtful but you never know) I could put some heatshrink over it to hold the petals together, stop them splaying out again.I don't know of the connectors can be replaced on these, or even if it's worth the cost.***UPDATE***The guy did get back to me and offer a refund, which is great. Although that will mean I'll end up having spent £30 (in fuel) for nothing. Might as well have pulled out £30 and set fire to it.I could keep it, try and bend the petals back. Although it's highly likely they will just snap, which will make it scrap and I'll be £55 worse off instead of £30

author: TheSteve
author_rank: Unknown
timestamp: June 13, 2020, 06:24:38 pm
content: That is a mess - may as well try to gently squeeze them back together with some fine tipped needle nose pliers. If you can get any kind of reasonable connection it will probably be just fine and you won't notice any issues. Chances are there will be larger impedance bumps from the coax etc.

author: 0culus
author_rank: Super Contributor
timestamp: June 13, 2020, 06:40:34 pm
content: Wow. N connectors are fairly robust (at least when you compare them to precision 3.5mm and smaller connectors), so someone worked rather hard to damage it like that. As Steve says you probably can carefully bend it back into place and it will probably work fine, at least at lower frequencies.

author: veedub565
author_rank: Frequent Contributor
timestamp: June 13, 2020, 06:48:14 pm
content: Thanks, no idea how they managed it. I've come across 75 ohm N-Types that have had a 50 ohm connector fitted and it seems a bit hit and miss. some bend back ok, and some just snap right off the moment you touch them.M7SCY

author: veedub565
author_rank: Frequent Contributor
timestamp: June 13, 2020, 06:53:04 pm
content: I might try contacting Diamond, see if they will supply a new connector. Doubtful, but you never know.

author: George Edmonds
author_rank: Frequent Contributor
timestamp: June 13, 2020, 07:03:03 pm
content: HiI have seen this type of damage to N connectors many times before, it is normally caused by IQ-1's trying to force a PL259 connector into an N. The average radio amateur would not recolonise or more importantly know how to fit an N connector.In my experience if you try to reform the centre socket some of the petals will break off. With a lot of these white stick aerials it is possible to drill out the retaining countersunk pop rivets and replace the N, but it is only to be attempted by someone with good mechanical skills.73 George G6HIG

author: George Edmonds
author_rank: Frequent Contributor
timestamp: June 13, 2020, 07:07:33 pm
content: HiThe N socket will be a standard type bulkhead single hole mounting type and readily available.73 George G6HIG

author: veedub565
author_rank: Frequent Contributor
timestamp: June 13, 2020, 07:32:16 pm
content: Thanks George.I did ask the seller if it was an N-Type or SO239. I wonder if they tried connecting an SO239 to find out.I was able to bend the petals somewhat, although they kept springing back. I put some heatshrink over and that helps hold them together. It ain't pretty but as long as it makes contact ok then should be alright.I'll see if I can source a replacement. A Friend has offered me a parts doner, but it's SO239 not N-Type.

author: TheMG
author_rank: Frequent Contributor
timestamp: June 14, 2020, 02:12:54 am
content: I would just give it a try bending back the fingers, very carefully. If you end up breaking one off, but all the other ones are intact and straightened, it will probably work just fine considering the frequencies this is operating at, and presumably you're not running super high power levels.I've also seen female N connectors get damaged from improperly assembled male N connectors, either the center pin being way off-center or protruding out far enough that the shoulder of the pin makes contact with the fingers.Quote from: veedub565 on June 13, 2020, 04:43:22 pmCompletely irrelevant whether or not the antenna was used for RX or TX. That would be like selling a car and telling the buyer "it's never been used to drive to the grocery store".

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: June 14, 2020, 04:36:40 am
content: Hi,There is a similar discussion with pictures here:https://www.elektroda.pl/rtvforum/topic2912729.htmlYou will need to use google translate or learn Polish.Regards,Jay_Diddy_B

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: July 02, 2020, 01:17:55 am
content: Replace the connector if you can, it may cause a bad SWR at high freq and might be a problem especially on transmit.An antenna analyzer or a vector network analyzer might show a relatively large problem.You do not need the really good N connectors, a cheaper one would probably be fine. Good ones are good to maybe 16 GHz.SO 239 are really not 50 ohm connectors (maybe 32 ohm at 30 MHz) and get worse at high freq, that's why N connectors are used.Wally

author: tkamiya
author_rank: Super Contributor
timestamp: July 06, 2020, 07:38:11 pm
content: What I would do is, try to reshape/reform those contacts carefully. It should be salvageable.Then, I would take N male to female adapter and screw that in, and keep it there. Once damaged like that, it won't be perfect. So I'd use a "connector saver" to avoid damaging coax or ever disturbing it again.