It would depend on what coax you are working with. Lately I've been using RG316, quite by accident I discovered that I can neatly remove the outer jacket with my Ideal strippers by using the 14AWG gate, carefully close the gate and stop just before the strippers start to pull the wire through the gate, release pressure on the handles, when possible rotate the cable 90 deg, repeat. Use your thumb nail to slide the jacket off. Now I cannot attest that there is no damage to the shielding, my eyes are 70 years old but I use magnifiers and I haven't noticed any shield strands coming adrift. Hope this helps someone. John VE7KKQ On Tue, Sep 21, 2021 at 11:57 AM Dragan Milivojevic <d.milivojevic@...> wrote: It depends what you mean by pro.
While I was working for a cable provider the service men
used cheap tools like these:
I usually use the first one for small diameter coax as it is much
faster than adjusting the second one.
For larger diameter coax, pipe cutter with a sharp blade works
great. This style:
Also get cable cutter pliers, especially when cutting larger diameter
cable.
Once you try it you'll newer go back to usual wire cutters that mangle up
the
dielectric and center lead. Something like this, but these are usually
cheaper
to get locally then on AliExpress:
On Tue, 21 Sept 2021 at 18:57, kk7xo via groups.io <kk7xo=
[email protected]> wrote:
I have a ratchet crimp connector and can install various types of
terminations. But what tool(s) do the pros use to strip coax? Any
suggestions?
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It depends what you mean by pro. While I was working for a cable provider the service men used cheap tools like these: I usually use the first one for small diameter coax as it is much faster than adjusting the second one. For larger diameter coax, pipe cutter with a sharp blade works great. This style: Also get cable cutter pliers, especially when cutting larger diameter cable. Once you try it you'll newer go back to usual wire cutters that mangle up the dielectric and center lead. Something like this, but these are usually cheaper to get locally then on AliExpress: On Tue, 21 Sept 2021 at 18:57, kk7xo via groups.io <kk7xo= [email protected]> wrote: I have a ratchet crimp connector and can install various types of
terminations. But what tool(s) do the pros use to strip coax? Any
suggestions?
|
On 9/21/21 11:14 AM, William Smith wrote: For instance, this is still a work in progress, but, for RG-8x:
BNC Connectors from HRO: Lands Precision BNC-10Z-DGN
N-type for RG-8x: (Silver) and (nickel)
Strip Tool: LP HT-322
Crimp Tool: LP DL-801G
Go together well.
The same tooling works with RG-58 and LP BNC-10F-DGN
Note that while the stripper is nearly perfect for RG-8x BNCs, it might require a little fidding for the other cables and connectors. The LP spec sheets show a wide range of strip lengths, and even LP doesn't sell the appropriate strip tooling. Go figure.
YMMV. That's why I eventually got the fancy adjustable one.? I had a single purpose for crimp on to RG58 for thinnet networks, worked great. But didn't quite work for other sizes. With the adjustments, I could fiddle with it until it was perfect for the connectors I had and the coax I had. They work up to about 1/2" diameter as long as it's a smooth shield. They won't work on corrugated shields (although I'm sure someone makes a stripper for that) It's kind of like the (wretchedly expensive) tools for semirigid and SMA connectors.? Get the right tool set up right, and you can crank out dozens of cables in a day, all perfect.
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For instance, this is still a work in progress, but, for RG-8x:
BNC Connectors from HRO: Lands Precision BNC-10Z-DGN
N-type for RG-8x: (Silver) and (nickel)
Strip Tool: LP HT-322
Crimp Tool: LP DL-801G
Go together well.
The same tooling works with RG-58 and LP BNC-10F-DGN
Note that while the stripper is nearly perfect for RG-8x BNCs, it might require a little fidding for the other cables and connectors. The LP spec sheets show a wide range of strip lengths, and even LP doesn't sell the appropriate strip tooling. Go figure.
YMMV.
73, Willie N1JBJ
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Show quoted text
On Sep 21, 2021, at 1:50 PM, Jim Lux <jim@...> wrote:
On 9/21/21 10:17 AM, Jim Lux wrote:
On 9/21/21 9:57 AM, kk7xo via groups.io wrote:
I have a ratchet crimp connector and can install various types of terminations. But what tool(s) do the pros use to strip coax? Any suggestions?
One of those multiblade spin around the coax
I've used a Paladin CST for decades.
I tried to find some catalog info, but you need to dig through distributors pages..
There's different flavors of these things. 2 and 3 level stripping, adjustable or not, whether are not you handle just one size of coax or multiples, etc.
The 2 level, fixed size coax ones are cheapest ($20-30), the fancy ones have cassettes that you can swap in if you regularly use multiple sizes of coax.
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On 9/21/21 10:17 AM, Jim Lux wrote: On 9/21/21 9:57 AM, kk7xo via groups.io wrote:
I have a ratchet crimp connector and can install various types of terminations.? But what tool(s) do the pros use to strip coax?? Any suggestions?
One of those multiblade spin around the coax
I've used a Paladin CST for decades. I tried to find some catalog info, but you need to dig through distributors pages.. There's different flavors of these things. 2 and 3 level stripping, adjustable or not, whether are not you handle just one size of coax or multiples, etc. The 2 level, fixed size coax ones are cheapest ($20-30), the fancy ones have cassettes that you can swap in if you regularly use multiple sizes of coax.
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Check your cal loads with an ohm meter to see if they are OK at DC.
Take a look at the inside socket of the SMA connectors. Perhaps "drilled out" by rotating pin after too may uses.
Roger
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Re: PC Boards for QEX Step Attenuator Available
Dick,
Does the article indicate how much "blow-by" you get (due to the mechanical switches in this design) as the frequency increases?
Roger
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On 9/21/21 9:57 AM, kk7xo via groups.io wrote: I have a ratchet crimp connector and can install various types of terminations. But what tool(s) do the pros use to strip coax? Any suggestions?
One of those multiblade spin around the coax I've used a Paladin CST for decades.
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I have a ratchet crimp connector and can install various types of terminations. But what tool(s) do the pros use to strip coax? Any suggestions?
|
PC Boards for QEX Step Attenuator Available
I have ordered a limited batch of boards from JLCPCB for the QEX September/October 2021 ¡°Miniature SMA Step Attenuator¡± pp 9-21 by Tom Alldred VA7TA.
If you are interested in a board, at $3.00 ppd CONUS, please reply off line [click the ¡°Private¡± button].
I expect to receive the boards in the first week of October and will have 8 spare boards available.
If there is sufficient additional interest, I would be willing to make a second order.
See attached for some additional info.
Dick K9IVB
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On 21/09/2021 13:45, Karl Jan Skontorp wrote: Hi all!
Is there anyone who can be so kind as to give me some help to make my device work again or at least tell me what has happened to my device?
I have a NanoVNA V2_2 - SAA-2N with the DiSlord firmware, version 1.0.69 - build time: Jul 31 2021 - 12:27:19.
The device has been working without problems for a long time, last time was yesterday or the day before. When I turned the device on today, I got a "strange" screen. I have always had a small point at the right in the smith-chart when input is open, a small point in the middle with 50ohm connected and a small point at the left, when shorted. Today I got something else! Please have a look at the pictures below. The open point is "big", 50ohm is smaller and short is still a small point. If I do a measurement, I get the correct "form", but the curve is not as "clear" line as I had earlier? I tried to load an older firmware, but the result is the same. I think there is a hardware error...
I will be very grateful for all the advice and views to solve the problem!
Karl Jan - LA3FY Karl, Cab you still calibrate the device. I wonder whether the calibration has been lost? 73, David GM8ARV -- SatSignal Software - Quality software for you Web: Email: david-taylor@... Twitter: @gm8arv
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Re: Sweeping an Antenna from the Shack
On 9/21/2021 8:39 AM, K8HTB wrote: One thing I have found is when tightening the pl259 you have to make sure the nubs are well seated in the so239 no air gaps. Good point. But, people should keep in mind that PL259 and N style connectors are two different animals. The outer shell of a PL259 is part of the Rf connection, but the outer shell of an N connector is just a mechanical connection. The RF connection of the N connector is internal to the outer shell and it is possible to over-tighten and N connector. Finger snug for an N connector is good. 73, Joe, K1ike
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Hi all!
Is there anyone who can be so kind as to give me some help to make my device work again or at least tell me what has happened to my device?
I have a NanoVNA V2_2 - SAA-2N with the DiSlord firmware, version 1.0.69 - build time: Jul 31 2021 - 12:27:19.
The device has been working without problems for a long time, last time was yesterday or the day before. When I turned the device on today, I got a "strange" screen. I have always had a small point at the right in the smith-chart when input is open, a small point in the middle with 50ohm connected and a small point at the left, when shorted. Today I got something else! Please have a look at the pictures below. The open point is "big", 50ohm is smaller and short is still a small point. If I do a measurement, I get the correct "form", but the curve is not as "clear" line as I had earlier? I tried to load an older firmware, but the result is the same. I think there is a hardware error...
I will be very grateful for all the advice and views to solve the problem!
Karl Jan - LA3FY
|
Re: Sweeping an Antenna from the Shack
One thing I have found is when tightening the pl259 you have to make sure the nubs are well seated in the so239 no air gaps.
Unfortunately it is easy to just screw the connection together and not realize the they are not together internally and I am sure that makes for a bad connection.
I push them together with the outer shell backed out and and try to rotate the inner if it turns it isn't hitting the nubs and is not seated.
Also I have used pliers tighten at times.
De K8HTB Joe
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Re: examples of effect of feedline loss on apparent VSWR
Even more interesting is to do a wide/multt-band sweep with the nanoVNA: You can easily see the effects of frequency on feedline losses in the loss.
I usually do a 1-30MHz sweep of my multiiband-HF antennas at both the feedpoint, and at the exciter (including any switches, transmatches, patch cables, etc).
-Mat, N8TW
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Re: Sweeping an Antenna from the Shack
On Sunday 19 September 2021 02:20:24 pm Roger Need via groups.io wrote: On Sun, Sep 19, 2021 at 11:05 AM, <kk7xo@...> wrote:
By the way, that J-Pole article Jim posted is great. I'd like to link to it
from my article. Is it available online? Like maybe the ARRL site?
Albert KK7XO
Here you go >>>
Roger Better, the pdf didn't include the figures... -- Member of the toughest, meanest, deadliest, most unrelenting -- and ablest -- form of life in this section of space, ?a critter that can be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters" - Information is more dangerous than cannon to a society ruled by lies. --James M Dakin
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Re: Sweeping an Antenna from the Shack
Howdy Albert,
You can get SMA connectors for RG-8X (and -59, any .242" coax), tho you do of course need the ratchet crimper with the appropriate dies.. I got both on amazon a while back.
PL-259s are not that bad; the modern ones with Teflon are supposedly considerably better than the old phenolic ones. And the impedance bump is a small fraction of the wavelength at 2M.
Consider that most 2 meter mobile antennas are using 15-18 feet of RG-58 and a PL-259...
Also, consider that final tuning of the antenna is measured at the radio end of the coax; the object being to get 50 ohms at the radio.
73, --kv5r
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Re: Sweeping an Antenna from the Shack
Since the antenna is SMA, would it make sense to put BNC connectors on the RG-8x and use a BNC->SMA adapter? Then not only do you avoid the PL-259 entirely, but you can easily calibrate at the SMA.
If you have the strip and crimp tools, BNC crimp for RG-8x is easy, but even if you don't, BNC solder/clamp for RG-8x isn't rocket science.
73, Willie N1JBJ
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Show quoted text
On Sep 19, 2021, at 11:33 AM, kk7xo via groups.io <kk7xo@...> wrote:
I want to sweep my 2 meter antenna from the end of a 15 to 18 foot coax. This is because I need to get the antenna out in the clear away from nearby objects to get a good indication of the actual VSWR. The antenna has an SMA connector. I have two pieces of coax I can use. One is 15' of LMR-100 with SMA connectors on both ends. The other is an 18' piece of RG-8X with PL-259 connectors at both ends. In either case I can move the plane of calibration to the end of the coax where the antenna connects.
So I have two questions for those who have a lot of VNA experience in this group:
1) Since LMR-100 is lossy at 2m frequencies, will I lose much precision in the sweep by calibrating at the end of the coax?
2) Am I better off using RG-8X knowing that I will need to adapt the PL-259 to SMA at both ends? I understand that PL-259 connectors are not so good at VHF and adding adapters will only make them worse.
Which is the better alternative?
Albert KK7XO
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Re: Sweeping an Antenna from the Shack
If you calibrate at the end of the cable, there should be no difference in either case.
But I would choose option 1 because the attenuation of 18 feet of LMR-100 at 145MHz is only 1.62 dB and the performance of this cable will be normal. The performance of PL-259 connectors is difficult to predict. They usually have a lower impedance than 50 Ohms. I have such a PL259/SO239 connector set that has 25 Ohms. This increases the SWR to 1.3 on 145MHz and on 433 to 2.3.
I did an experiment once, I compared the results of antenna measurements on 433 connected directly, and using this bad PL259/SO239 25 Ohm set calibrating before the set and after the set. The calibration compensated for the error interjected by those connectors and the results were almost identical.
Green - direct connected antenna
Red - Antenna connected through wrong PL259/SO239 adapter set
Blue - Antenna connected through wrong PL259/SO239 adapter set, but calibrated after adapter set.
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Re: Sweeping an Antenna from the Shack
On Sun, Sep 19, 2021 at 11:33 AM, <kk7xo@...> wrote:
I have two pieces of coax I can use.
It's a bit late now for this reply, but here goes - Do it with both cables, and compare the results. Then you could share the results, too! I think it would be an interesting comparison. -- Doug, K8RFT
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Roger Need
David J Taylor
Mat Breton
