Re: [time-nuts] TNC connectors
In a message dated 23/06/2009 09:29:38 GMT Daylight Time, david.partri...@dsl.pipex.com writes: The T-Bolt manual recommends 75 ohm coax, so will a 75 ohm TNC mate with a 50 ohm TNC without problems? Though I suppose for a short run of cable, 50 ohm will be OK? - Hi David There's been some previous discussion on this, perhaps an archive search will throw up past comments, and probably with usual Time-Nuts overkill:-). According to the manual the Thunderbolt antenna input impedance is 50ohms, despite their using an F connector, but they recommend using 75 ohm cable on the basis that it tends to have lower loss for a given size. Unless you're planning on really long runs I'd suggest just sticking with 50 ohm cable and connectors. I've got a couple of commercial antennas that come with predefined lengths of cable, 20 metres if I remember correctly, and these use RG58. I'm not sure if you'll get a TNC to F type adapter anyway, so you might have to revert to BNC on the cable at the Thunderbolt end. The mounting pole thread seems to be fairly standard but not sure on availability of threaded poles. One option would be a stub mounting plate as sold for marine use, one current ebay item for example is 250430681103, and a further search in the marine section might prove useful. regards Nigel GM8PZR ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] TNC connectors
In a message dated 23/06/2009 11:00:13 GMT Daylight Time, d...@uk-ar.co.uk writes: However, it's years since I saw a 75r version, so I don't know for sure. Doing that with BNC's will lead to a flaky connection, as the centre pin on the 75r ones is much smaller. The other way round (50r plug into 75r socket) will damage the socket. As TNC's are very similar to BNC's ??? This belief about BNC connectors seems to be an urban myth, although admittedly one that I shared for many years. Whether or not it has been true at some time in the past, or of some manufacturers, I don't know but the following is a current quote from Amphenol --- Two distinct types of 75 Ω BNCs are available, and both mate with each other and with 50 Ω BNCs. Type 1 is designated 75 Ω BNC-T1 and provides constant 75 Ω performance with low VSWR DC – 4 GHz. Type 2 is designated 75 Ω BNC-T2 and is usable with low reflection DC - 1 GHz. For applications above 1 GHz, Type 1 is recommended. The full text of this can be found at _http://www.amphenolconnex.com/products/bnc.asp_ (http://www.amphenolconnex.com/products/bnc.asp) and I've seen similar comments from other manufacturers. regards Nigel GM8PZR ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] TNC connectors
Hi Dave, The Solartron 7081 is very happy and so am I :-). Thanks yet again for all your help. Re: different sized centre pins - I know that's true of N type connectors, - you really don't want to push an N type male 50R into an N type female 75R connector. However I'm pretty sure that it doesn't apply to BNC - just wasn't sure about TNC. Dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] TNC connectors
David, I used a piece of pvc conduit to mount the antenna. It fits in the vic-100's mounting skirt. If it does not have a mounting skirt, perhaps use a flange and drill the appropriate holes, apply RTV (or your favorite sealant!). Norm (The divider board is working like a charm!! Even impressed the heck out of my new GF!!! GKK!!!) David C. Partridge wrote: Hi Dave, The Solartron 7081 is very happy and so am I :-). Thanks yet again for all your help. Re: different sized centre pins - I know that's true of N type connectors, - you really don't want to push an N type male 50R into an N type female 75R connector. However I'm pretty sure that it doesn't apply to BNC - just wasn't sure about TNC. Dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] TNC connectors
Norman, PVC conduit sounds like a good solution. I'm delighted to hear the frequency divider board is performing good service. I was rather surprised when there was insufficient interest to justify getting a further batch of boards made up. I'm pretty sure it would out-perform any micro based solution (no disrespect to the TAPR board intended) in terms of jitter etc. especially if you used thin film resistors instead of thick film in the clock circuit, but don't have the test equipment to measure that. I wonder if anyone did get round to measuring how good or bad it was - I did try (with a lot of help from Bruce) to design it to minimise that sort of problem. Dave -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Norman J McSweyn Sent: 23 June 2009 11:54 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] TNC connectors David, I used a piece of pvc conduit to mount the antenna. It fits in the vic-100's mounting skirt. If it does not have a mounting skirt, perhaps use a flange and drill the appropriate holes, apply RTV (or your favorite sealant!). Norm (The divider board is working like a charm!! Even impressed the heck out of my new GF!!! GKK!!!) David C. Partridge wrote: Hi Dave, The Solartron 7081 is very happy and so am I :-). Thanks yet again for all your help. Re: different sized centre pins - I know that's true of N type connectors, - you really don't want to push an N type male 50R into an N type female 75R connector. However I'm pretty sure that it doesn't apply to BNC - just wasn't sure about TNC. Dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] TNC connectors
Dave Baxter wrote: Doing that with BNC's will lead to a flaky connection, as the centre pin on the 75r ones is much smaller. The other way round (50r plug into 75r socket) will damage the socket. As TNC's are very similar to BNC's ??? You are thinking of the incompatibility between 50 ohm and 75 ohm *N* connectors. 75 ohm BNC are use the same center pin hardware as 50 ohm BNC. The only difference is in the white plastic (teflon) insulator. In the 50 ohm BNC, the center insulator goes all the way to the tip of the center pin. In the 75 ohm BNC, the center insulator is abbreviated. HP/Agilent uses 75 OHM BNC's on several of its devices that have switchable impedances. For example, the 3586C. -Chuck Harris ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] TNC connectors
Message: 3 Date: Tue, 23 Jun 2009 07:54:02 -0400 From: Chuck Harris cfhar...@erols.com Subject: Re: [time-nuts] TNC connectors To: Discussion of precise time and frequency measurement time-nuts@febo.com Message-ID: 4a40c25a.7080...@erols.com Content-Type: text/plain; charset=ISO-8859-1; format=flowed Dave Baxter wrote: Doing that with BNC's will lead to a flaky connection, as the centre pin on the 75r ones is much smaller. The other way round (50r plug into 75r socket) will damage the socket. As TNC's are very similar to BNC's ??? You are thinking of the incompatibility between 50 ohm and 75 ohm *N* connectors. 75 ohm BNC are use the same center pin hardware as 50 ohm BNC. The only difference is in the white plastic (teflon) insulator. In the 50 ohm BNC, the center insulator goes all the way to the tip of the center pin. In the 75 ohm BNC, the center insulator is abbreviated. HP/Agilent uses 75 OHM BNC's on several of its devices that have switchable impedances. For example, the 3586C. -Chuck Harris Indeed looking as some more data sheets. However, I have somewhere in the deed box at home, some Ex BT BNC's, marked up as 75 Ohm, that have very much smaller center pin's than the common or garden 50r types, as well as less plastic in there too. We once had a Novell computer network in the office, that used 93r coax cable, and 50r BNC's, at 100MBPS. Using Thomas Conrad cards I seem to remember. We still have the real of 93r coax. (It was very much faster end to end, and much more stable than the TCP/IP based Microsoft network we have now, but I digress.) In general, yes indeed size for size, 75r coax will be less lossy than 50r types, but if the RX does present a nominal 50r load, they may be some potential issues. However, if the antenna is an active type, it's probably not worth fussing over. Enough people have used what's recomended I guess and found no problems. Just use good quality cable, not the so called Low loss TV coax. I'd guess the foam dielectric Satelite LNB cable would do. It fit's 'F' connectors too. Cheers All. Dave B. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] TNC connectors
Hmmm now all I have to do is find a TNC connector to fit FT100 (or RG6) without paying 5 times thet value of the connector for shipping - or just use RG58 as I've got BNC for this, and can easily get TNC for it too. Thanks to all Dave -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Dave Baxter Sent: 23 June 2009 13:40 To: time-nuts@febo.com Subject: Re: [time-nuts] TNC connectors Message: 3 Date: Tue, 23 Jun 2009 07:54:02 -0400 From: Chuck Harris cfhar...@erols.com Subject: Re: [time-nuts] TNC connectors To: Discussion of precise time and frequency measurement time-nuts@febo.com Message-ID: 4a40c25a.7080...@erols.com Content-Type: text/plain; charset=ISO-8859-1; format=flowed Dave Baxter wrote: Doing that with BNC's will lead to a flaky connection, as the centre pin on the 75r ones is much smaller. The other way round (50r plug into 75r socket) will damage the socket. As TNC's are very similar to BNC's ??? You are thinking of the incompatibility between 50 ohm and 75 ohm *N* connectors. 75 ohm BNC are use the same center pin hardware as 50 ohm BNC. The only difference is in the white plastic (teflon) insulator. In the 50 ohm BNC, the center insulator goes all the way to the tip of the center pin. In the 75 ohm BNC, the center insulator is abbreviated. HP/Agilent uses 75 OHM BNC's on several of its devices that have switchable impedances. For example, the 3586C. -Chuck Harris Indeed looking as some more data sheets. However, I have somewhere in the deed box at home, some Ex BT BNC's, marked up as 75 Ohm, that have very much smaller center pin's than the common or garden 50r types, as well as less plastic in there too. We once had a Novell computer network in the office, that used 93r coax cable, and 50r BNC's, at 100MBPS. Using Thomas Conrad cards I seem to remember. We still have the real of 93r coax. (It was very much faster end to end, and much more stable than the TCP/IP based Microsoft network we have now, but I digress.) In general, yes indeed size for size, 75r coax will be less lossy than 50r types, but if the RX does present a nominal 50r load, they may be some potential issues. However, if the antenna is an active type, it's probably not worth fussing over. Enough people have used what's recomended I guess and found no problems. Just use good quality cable, not the so called Low loss TV coax. I'd guess the foam dielectric Satelite LNB cable would do. It fit's 'F' connectors too. Cheers All. Dave B. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] TNC connectors
Dave Baxter wrote: Indeed looking as some more data sheets. However, I have somewhere in the deed box at home, some Ex BT BNC's, marked up as 75 Ohm, that have very much smaller center pin's than the common or garden 50r types, as well as less plastic in there too. Connectors that deviate from standards were at one time pretty common. The Ex BT BNC's in your junk box are undoubtedly an example. I have run into carbon copies of the old PL259/SO239 UHF connectors that were identical in all respects, including the nomenclature markings, but were metric threaded. And, I have run into alleged BNC's that looked like they were ok, but wouldn't mate with anything I could find. They were a silly millimeter bigger in diameter. We once had a Novell computer network in the office, that used 93r coax cable, and 50r BNC's, at 100MBPS. Using Thomas Conrad cards I seem to remember. We still have the real of 93r coax. 93 ohm coax is standard fare for automobile AM radios in the US. Its claim to fame is its very low capacitance per foot. (It was very much faster end to end, and much more stable than the TCP/IP based Microsoft network we have now, but I digress.) In general, yes indeed size for size, 75r coax will be less lossy than 50r types, but if the RX does present a nominal 50r load, they may be some potential issues. Unlikely. The biggest issue would be edge smearing caused by the received signal bouncing up and down the length of the coax. This effect is minimized because the mismatch is small, and the loss of the coax is pretty high. However, if the antenna is an active type, it's probably not worth fussing over. Enough people have used what's recomended I guess and found no problems. Just use good quality cable, not the so called Low loss TV coax. What a thing to say! Quad shielded RG-6 is the minimum quality you will find for today's TV and cable systems. Even RadioShack sells it. It is the same stuff used by the satellite TV guys. I'd guess the foam dielectric Satelite LNB cable would do. It fit's 'F' connectors too. That is because Satellite LNB's use Quad RG 6. Normal TV coax. -Chuck Harris ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] TNC connectors
I just bought two of these antennas from Bob (fluke.l) and asked him to throw in adapters from TNC on the antenna to female F so I can use ordinary 75 ohm cable TV coax from rat shack. He charged an extra $5 for the adapters which I think is a pretty good deal. Still waiting on delivery so I don't know for sure what was thrown in the box but I'll let you guys know if there was a problem. -Bob On Tue, Jun 23, 2009 at 7:50 AM, David C. Partridge david.partri...@dsl.pipex.com wrote: Hmmm now all I have to do is find a TNC connector to fit FT100 (or RG6) without paying 5 times thet value of the connector for shipping - or just use RG58 as I've got BNC for this, and can easily get TNC for it too. Thanks to all Dave -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Dave Baxter Sent: 23 June 2009 13:40 To: time-nuts@febo.com Subject: Re: [time-nuts] TNC connectors Message: 3 Date: Tue, 23 Jun 2009 07:54:02 -0400 From: Chuck Harris cfhar...@erols.com Subject: Re: [time-nuts] TNC connectors To: Discussion of precise time and frequency measurement time-nuts@febo.com Message-ID: 4a40c25a.7080...@erols.com Content-Type: text/plain; charset=ISO-8859-1; format=flowed Dave Baxter wrote: Doing that with BNC's will lead to a flaky connection, as the centre pin on the 75r ones is much smaller. The other way round (50r plug into 75r socket) will damage the socket. As TNC's are very similar to BNC's ??? You are thinking of the incompatibility between 50 ohm and 75 ohm *N* connectors. 75 ohm BNC are use the same center pin hardware as 50 ohm BNC. The only difference is in the white plastic (teflon) insulator. In the 50 ohm BNC, the center insulator goes all the way to the tip of the center pin. In the 75 ohm BNC, the center insulator is abbreviated. HP/Agilent uses 75 OHM BNC's on several of its devices that have switchable impedances. For example, the 3586C. -Chuck Harris Indeed looking as some more data sheets. However, I have somewhere in the deed box at home, some Ex BT BNC's, marked up as 75 Ohm, that have very much smaller center pin's than the common or garden 50r types, as well as less plastic in there too. We once had a Novell computer network in the office, that used 93r coax cable, and 50r BNC's, at 100MBPS. Using Thomas Conrad cards I seem to remember. We still have the real of 93r coax. (It was very much faster end to end, and much more stable than the TCP/IP based Microsoft network we have now, but I digress.) In general, yes indeed size for size, 75r coax will be less lossy than 50r types, but if the RX does present a nominal 50r load, they may be some potential issues. However, if the antenna is an active type, it's probably not worth fussing over. Enough people have used what's recomended I guess and found no problems. Just use good quality cable, not the so called Low loss TV coax. I'd guess the foam dielectric Satelite LNB cable would do. It fit's 'F' connectors too. Cheers All. Dave B. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] TNC connectors
[snip] On my FTS antenna it's just a standard 1 NPT male thread (NPT = National Pipe Thread). Any US plumbing supply store or home improvement store will sell you iron pipe threaded that way or adapters to go to PVC or copper. -John PS Where do you get the (1 diameter?) threaded poles these antennas screw onto? Cheers David Partridge ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] TNC connectors
If the thread measures 1 inch, it isn't 1 inch pipe thread. It is more likely 1/2 inch pipe thread, or possibly 3/4 inch, depending on how accurately you measured. 1 inch pipe is 1-3/8 inch OD, 3/4 inch pipe is 1-1/16 inch OD, and 3/4 inch pipe is 7/8 inch OD. -Chuck Harris J. Forster wrote: [snip] On my FTS antenna it's just a standard 1 NPT male thread (NPT = National Pipe Thread). Any US plumbing supply store or home improvement store will sell you iron pipe threaded that way or adapters to go to PVC or copper. -John PS Where do you get the (1 diameter?) threaded poles these antennas screw onto? Cheers David Partridge ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] TNC connectors
I just took the antenna to Home Depot and looked through the bins, found something that fit well, paid, and left. LoL. Whatever the nominal Pipe size, mine is NPT for sure. -John == If the thread measures 1 inch, it isn't 1 inch pipe thread. It is more likely 1/2 inch pipe thread, or possibly 3/4 inch, depending on how accurately you measured. 1 inch pipe is 1-3/8 inch OD, 3/4 inch pipe is 1-1/16 inch OD, and 3/4 inch pipe is 7/8 inch OD. -Chuck Harris J. Forster wrote: [snip] On my FTS antenna it's just a standard 1 NPT male thread (NPT = National Pipe Thread). Any US plumbing supply store or home improvement store will sell you iron pipe threaded that way or adapters to go to PVC or copper. -John PS Where do you get the (1 diameter?) threaded poles these antennas screw onto? Cheers David Partridge ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] TNC connectors
Hello Dave, I looked for that antenna but could not find it, to understand how to mate to it. Consider using to a coaxial adapter at the antenna, TNC male to BNC female. Then put a BNC male connector on whatever coax you will be using. In an ideal world, a 75 ohm TNC will NOT mate a 50 ohm TNC. May feel like it is screwed in properly but the diameter of the center pin is smaller for the 75 ohm version. So, if you jam in a larger 50 ohm male center pin into a smaller 75 ohm female center pin, you will destroy it. Having said that, most connectors you find will be 50 ohm, just be watchful for the odd ball. I got my chromed pipe for the GPS antenna from a friend. Actual O.D. is 1.007 and the male thread looks to be a straight thread. Check the specs on the Panasonic antenna for the mating thread required. Check out the Home Depot's plumbing section for either galvi pipe or white PVC pipe. The electrical section will have a grey PVC pipe that may be more suitable and UV proof. Stan, W1LE Cape Cod FN41sr David C. Partridge wrote: I'm thinking of buying a Panasonic VIC100 timing antenna with a 50 ohm TNC connector (I assume) from fluke.l on eBay, as the room I use for my den has moved to one without a view to the south, so I can't use the puck antenna mounted just outside the window any more. The T-Bolt manual recommends 75 ohm coax, so will a 75 ohm TNC mate with a 50 ohm TNC without problems? Though I suppose for a short run of cable, 50 ohm will be OK? PS Where do you get the (1 diameter?) threaded poles these antennas screw onto? Cheers David Partridge ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] TNC connectors
Hi John, I only mentioned it so that someone wouldn't measure 1 inch, and walk off to Home Depot and ask for 1 inch, only to be in for a big surprise. -Chuck Harris J. Forster wrote: I just took the antenna to Home Depot and looked through the bins, found something that fit well, paid, and left. LoL. Whatever the nominal Pipe size, mine is NPT for sure. -John == If the thread measures 1 inch, it isn't 1 inch pipe thread. It is more likely 1/2 inch pipe thread, or possibly 3/4 inch, depending on how accurately you measured. 1 inch pipe is 1-3/8 inch OD, 3/4 inch pipe is 1-1/16 inch OD, and 3/4 inch pipe is 7/8 inch OD. -Chuck Harris ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] TNC connectors
True. I always take the to be mated part w/ me to avoid repeat trips. -John = Hi John, I only mentioned it so that someone wouldn't measure 1 inch, and walk off to Home Depot and ask for 1 inch, only to be in for a big surprise. -Chuck Harris J. Forster wrote: I just took the antenna to Home Depot and looked through the bins, found something that fit well, paid, and left. LoL. Whatever the nominal Pipe size, mine is NPT for sure. -John == If the thread measures 1 inch, it isn't 1 inch pipe thread. It is more likely 1/2 inch pipe thread, or possibly 3/4 inch, depending on how accurately you measured. 1 inch pipe is 1-3/8 inch OD, 3/4 inch pipe is 1-1/16 inch OD, and 3/4 inch pipe is 7/8 inch OD. -Chuck Harris ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
