Metcal MX-500P II RF connector - Page 1
Forum section: electronics / repair

author: GreyWoolfe
author_rank: Unknown
timestamp: August 04, 2015, 11:53:45 am
content: I now have a Metcal soldering station. Whilst playing with it last night, I found a problem with the second output. The Talon connector wouldn't seat. Using magnification, I saw that there was what appeared to be a piece of metal blocking the center hole. I tried to move it out of the way with a dental pick, but it sprung right back to blocking the hole. Sorry that I can't provide a picture, I just don't have a camera good enough to show detail that small. Has anyone replaced the RF connector? If so, do you have a part number/source for it? I don't have a proper torx driver to take the unit apart so if I can get a replacement part at the same time I order the driver, I can move on to repair the unit.

author: tautech
author_rank: Super Contributor
timestamp: August 05, 2015, 02:57:41 am
content: Would it be worth changing to a screwlocking DIN connector? Google it.

author: BurningTantalum
author_rank: Frequent Contributor
timestamp: August 05, 2015, 10:37:20 am
content: Tautech- Probably not. The sockets are mounted directly onto the PCB and the case is designed to mount 'onto them'. Plus they are extremely close to the incoming mains PCB tracks. Then the co-ax on the wand is really small, dual screened and a bit fiddly to replace into the standard F-connector. It would also result in having to modify future wands.GreyWoolfe- Do you mean that there is a bit of 'wire' stuck in the centre of the socket on the unit? The connector on the end of the wand lead is a standard format F-connector, but it has a gold plated pin rather than the co-ax 'inner' poking out as would be the case with a normal fit to a cable. Do you have the gold pin in the centre of the connector on the cable?regards, BT

author: GreyWoolfe
author_rank: Unknown
timestamp: August 05, 2015, 01:27:06 pm
content: First off, again I apologize for not having a camera that is good enough for some closeup pictures. No, there is no bit of wire stuck in the connector. It appears that there are 2 pieces of springy metal inside that I would guess make contact with the center pin of the cable connector when inserted. They appear to be bent to the point where 1 piece is centered right in the hole the center pin goes into. I tried to bend it back with a dental pick but being springy in nature, it goes right back to blocking the hole. I suspect there is damage in the connector. I can wiggle the Talon connector on, but the PSU LED indicates it not connected. The Talon connector is fine, it works in the first channel and there is a gold pin in the center. The way I look at it, if I can repair it, fine. If I can't. fine, the first channel works so I have a single output unit instead of a dual output. Being that I bartered for it and have no money into it, it's worth trying to bring it back to full functionality. I'd rather not have to switch back and forth between wand and tweezers causing unnecessary wear and tear on the unit. What I find odd is the lack of any real service info with pictures. The parts list doesn't even give a part number for the pcb connector. Once the Torx driver arrives next week, I will have a go at taking it apart and see what I can see. Hopefully, I can find a replacement connector and have it fully functional.Since it never hurts to ask, would it be out of the realm of possibility for someone that has this unit to open it up and see if there is a part number on the RF connector or take some good pictures that I can try to match it on an internet search? That would be so appreciated.

author: KJDS
author_rank: Super Contributor
timestamp: August 05, 2015, 01:51:25 pm
content: I've just opened one of mine up, no part number, base is 0.375" square and the threaded section is 0.6" long

author: KJDS
author_rank: Super Contributor
timestamp: August 05, 2015, 01:58:24 pm
content: and here's a picture

author: Nermash
author_rank: Frequent Contributor
timestamp: August 05, 2015, 02:00:18 pm
content: Looks to me like a standard pcb mount F connector.

author: tautech
author_rank: Super Contributor
timestamp: August 05, 2015, 02:07:09 pm
content: Something like this?http://www.rfstreet.com/ch_contentd.asp?id=2412

author: GreyWoolfe
author_rank: Unknown
timestamp: August 05, 2015, 03:09:40 pm
content: Thanks KJDS and Tautech. Tautech, I am going to order a couple from the site you gave me. If I am going to replace 1, I might as well replace both and have them both be new.

author: GreyWoolfe
author_rank: Unknown
timestamp: August 05, 2015, 03:17:02 pm
content: here's another question before I order. Is there a way to tell if it is a 50 or 75 Ohm connector?Edit: OK, this seems to be a stupid question. The link Tautech gave showed 50 Ohm impedance. Further internet searching shows it to be 75 Ohm. I asked as I didn't think F connectors came in 75 Ohm impedance. I should be awake by now, I've only been up 5 hours.

author: tautech
author_rank: Super Contributor
timestamp: August 05, 2015, 03:52:26 pm
content: Quote from: GreyWoolfe on August 05, 2015, 03:17:02 pmThey're probably most commonly seen as input connectors in spectrum analyzer's and therefore 50 ohhm.

author: KJDS
author_rank: Super Contributor
timestamp: August 05, 2015, 03:54:25 pm
content: Quote from: tautech on August 05, 2015, 03:52:26 pmThe only time I've ever seen them is for domestic satellite receivers and therefore 75 ohmat 13MHz, it will make the square root of diddly squat difference

author: GreyWoolfe
author_rank: Unknown
timestamp: August 05, 2015, 04:42:07 pm
content: Quote from: tautech on August 05, 2015, 03:52:26 pmThat's the funny thing, the link you provided showed it to be 50 ohm. I went looking cheaper and the site came up again through their ebay store and the same part number was listed as 75 ohm. All the other ebay listings were 75 ohm. I have only ever seen 75 ohm as I don't have an SA.I forgot to add that I ordered a couple and they are on their way from China. What was interesting, Mouser doesn't carry PCB F connectors. I wanted to order from them as I had a parts order project going already.

author: piranha32
author_rank: Unknown
timestamp: August 05, 2015, 11:50:37 pm
content: Quote from: tautech on August 05, 2015, 03:52:26 pmWhich SA uses F connector? All the SAs that I've seen had N connectors.BTW the description on rfstreet.com is misleading. It says that the impedance is 50ohm, but if you scroll down a bit, the impedance rises to 75ohm. Since the F connectors are mainly used in TV equipment, it's very unlikely that there exists 50ohm version.

author: helius
author_rank: Super Contributor
timestamp: August 06, 2015, 12:10:11 am
content: 50 ohm coax is the standard type used by most test equipment (not just spectrum analyzers) and shortwave/microwave radio gear.The only places where 75 ohm coax is widely used is in video (including CATV, and SDI video) and S/PDIF digital audio applications.The F connector is based on the dimensions of 75-ohm RG6 coax. Most male F connectors have no center pin, but are constructed so the wire of the cable protrudes into the female. There are 50-ohm F connectors, but they are constructed differently (http://www.air802.com/f-male-50-ohm-crimp-connector-rg58-lmr195.html).

author: Nermash
author_rank: Frequent Contributor
timestamp: August 06, 2015, 06:33:50 am
content: I have been dealing with F connectors and N connectors for 15 years now, and I have yet to see a 50 ohm F connector and 75 ohm N connectorI know that they are out there, but no one seems to use them...Regarding using F connector as a input to SA, it is commonly used for SAs that are TV&SAT analyzers, with 75 ohm F inputs.

author: piranha32
author_rank: Unknown
timestamp: August 06, 2015, 06:37:04 am
content: Quote from: Nermash on August 06, 2015, 06:33:50 amNiche application

author: Mephitus
author_rank: Regular Contributor
timestamp: August 06, 2015, 02:24:49 pm
content: From one of my fave sites for RF:http://www.rfsupplier.com/connector-c-148_86_114.htmlThere are several PCB mount 75ohm F connectors on there. I have purchased a couple other wifi antennas from them previously, pretty reasonable turnaround time of a day or two. Hope that helps. I got a metcal not too long ago too. A little too poor to buy any tips yet. Cant wait to use it.

author: GreyWoolfe
author_rank: Unknown
timestamp: August 06, 2015, 04:01:26 pm
content: Thanks, Mephitus, for the link. I will save it and maybe avoid the slow boat from China the next time. I understand the poor part. I am going to sell one of my Astron 35A power supplies after I put a couple of bucks into it with an inrush current reducer mod and a bleeder resistor (don't have the parts on hand). That will fund the purchase of the wand and cradle and maybe a tip or two. I will also see what else I am not using to recycle for cash for tips. If you aren't aware, Thermaltronics makes tips that fit Metcal and are cheaper. That's the route I am going for my wand/cradle and tip needs. I am awaiting an email to see if their MTX series tweezers tips will fit the Talon. Big price difference.

author: Mephitus
author_rank: Regular Contributor
timestamp: August 06, 2015, 04:33:58 pm
content: Thanks for the heads upI was going to snag a tip or two off ebay for $12 or under. May not be much money, but I am still recovering from a bankruptcy last year. If the thermaltronics are cheaper, that might help as I was really interested in getting a few different temps. I took apart my handset and the construction seems simple enough, you might be able to build one that works just as well for just a few bucks.