EEVblog® Electronics Community Forum
Products => Test Equipment => Topic started by: Squarewave on June 17, 2026, 03:29:08 pm
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Hello, I'm wondering if someone can suggest a better cable for my test leads for use with a VNA and SA.
I've been using some I made with RG58, which appear to be ok, but RG58 isn't really the best quality. I have more cables I'd like to make, so was thinking of something like LMR195, probably would need the 195 ultra flex. What have you guys used?
Thanks.
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This is a giant, and potentially very expensive, can of worms.
What frequency range are you looking for?
Also, check out this related thread: https://www.eevblog.com/forum/testgear/cables-connectors-(nsmabnc)-adapters-with-measured-results-for-comparisons/ (https://www.eevblog.com/forum/testgear/cables-connectors-(nsmabnc)-adapters-with-measured-results-for-comparisons/)
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So I realise any losses are calibrated out, but I'm generally using half a metre to 1 metre max. I used crimp/solder SMA plugs. I usually only go up to 500mhz, I've no work in the Ghz range, but perhaps I should consider the VNA does go up to 1.3Ghz.
I'll have a read of that thread, thanks.
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In that frequency range, the M&P cables are good. Gore cables are better. But it really depends on what you want to budget. It's easy to spend a ton of $$$.
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I would (and am) using RG400 cables for anything that I make myself for the lab. You can use connectors for RG58 (it's a close enough fit).
They are on the stiffer side, but have a much better shielding & PIM compared to any of the LMR stuff.
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Get double shielded cables for more precise work.
Best
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In that frequency range, the M&P cables are good. Gore cables are better. But it really depends on what you want to budget. It's easy to spend a ton of $$$.
Have you got a link to M&P? I was able to find Gore.
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In that frequency range, the M&P cables are good. Gore cables are better. But it really depends on what you want to budget. It's easy to spend a ton of $$$.
Have you got a link to M&P? I was able to find Gore.
here ya go: https://messi.it/en/catalogue/50-ohm-rf-coaxial-cable/n-male-connectors/hyperflex5/solder.htm
HF5 should be fine in the frequencies you're using, but going up to 7 or 10 gets better performance. I've shown them, and Gore, in the other thread.
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In that frequency range, the M&P cables are good. Gore cables are better. But it really depends on what you want to budget. It's easy to spend a ton of $$$.
Have you got a link to M&P? I was able to find Gore.
here ya go: https://messi.it/en/catalogue/50-ohm-rf-coaxial-cable/n-male-connectors/hyperflex5/solder.htm
HF5 should be fine in the frequencies you're using, but going up to 7 or 10 gets better performance. I've shown them, and Gore, in the other thread.
Ah yes Messi & Paoloni, I use their UF7 for my HF antenna and patch leads. You know what, I never considered looking at them for 5mm cable (5mm max really for bench top test work), so thanks for the heads up. M&P cables often have better characteristics than the likes of LMR.
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One thing to keep in mind about VNA cables is that while you can cal out many cable imperfections, you can't "cal out" a cable that is not phase or temperature stable. In particular, phase stability (during flexure) is one of the things that you're paying for when you spend $$$ on VNA cables.
Or, you could buy a big roll of tape and secure the cable to the bench that way :)
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One thing to keep in mind about VNA cables is that while you can cal out many cable imperfections, you can't "cal out" a cable that is not phase or temperature stable. In particular, phase stability (during flexure) is one of the things that you're paying for when you spend $$$ on VNA cables.
Yup. This is where the Gore cables excelled compared to all the others I've tried.
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Agreed. And that's why I keep cheking eBay and keep spending money on Gore :palm:
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I can not recommend HF5 (Hyperflex 5)
Loses are ok even at 1,3Ghz (which does not matter much for VNA use)
But the SRL / (Structual return Loss) is not meeting its specification 0,3-600MHz > 28 dB
I measure more something like 20-23dB (different lengths 2m - 6m)
Hyperflex 10 meets its specifications of 0,3-600MHz >30dB
Hyperflex 5 seems also sensitive to bending/flexing and don't be "hard" to it, it deforms easily.
HF10 seems also significant better in this respect but is a little un-handy for lab use.
I got some 0,5m cables made of RG142-PUR (5mm diameter) they are very good in respect til bending/flexing
But it is not widely available.
Knud
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For GHz VNA measurements, I use RG402, sometimes it's called SS402. It also what comes with the LiteVNA for example.
It's semi-rigid, so it's not the easiest to work with, and you can absolutely damage it if you bend it the wrong way.
But it's reliable, low loss, and you can solder the connector or the cable yourself. Meaning that it doesn't require expensive blanking/crimping tools.
And you can buy pre-made cables, with high quality stainless connectors, that cost like 1/20th of the price of the typical name brand VNA cable.
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I can not recommend HF5 (Hyperflex 5)
Loses are ok even at 1,3Ghz (which does not matter much for VNA use)
But the SRL / (Structual return Loss) is not meeting its specification 0,3-600MHz > 28 dB
I measure more something like 20-23dB (different lengths 2m - 6m)
Hyperflex 10 meets its specifications of 0,3-600MHz >30dB
Hyperflex 5 seems also sensitive to bending/flexing and don't be "hard" to it, it deforms easily.
HF10 seems also significant better in this respect but is a little un-handy for lab use.
I got some 0,5m cables made of RG142-PUR (5mm diameter) they are very good in respect til bending/flexing
But it is not widely available.
Knud
There's no question that HF5 is not as good as its older siblings, but if it's made well enough, it should meet its specs. Here's one I made:
(https://www.eevblog.com/forum/testgear/cables-connectors-(nsmabnc)-adapters-with-measured-results-for-comparisons/?action=dlattach;attach=2809379;image)
...and I'm not claiming I did a very good job making it. ;)
It is more sensitive to bends, especially if the connector installation quality is questionable...which I found out when I made questionable connections at the ends. :-DD
Thanks,
Josh
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Interesting :)
This one is 2m long with special N-connector for that cable type, crimped.
CAL-set is Siglent F503
Have another 2m piece ..look the same, also a 6m piece..same.
cables are approx 3 years old and has not been subject to violence.
Knud
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This is a RG400 from ROSNOL 1m N-connector crimped.
Teflon, double shielded, inner and shield is steel/copper silverplated.
Much better and ruggedized
Knud
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Interesting :)
This one is 2m long with special N-connector for that cable type, crimped.
CAL-set is Siglent F503
Have another 2m piece ..look the same, also a 6m piece..same.
cables are approx 3 years old and has not been subject to violence.
Knud
Hyperflex 5 doesn't have an official N crimp connector. That's what I like the least about it. ;)
My cable is with their connectors: https://messi.it/en/catalogue/50-ohm-rf-coaxial-cable/n-male-connectors/hyperflex5/solder.htm
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Other manufacturers make the same cable and connectors.
Soldering the center pin in a 5mm cable with foam isolation, is risky...very little heat melt the foam and offset the center conductor.
Crimping is always preferable unless we talk about teflon cables.
Maybe there is fluctuating quality...seen before amongst some European cable manufacturers in there competition for lowest attenuation.
They use low density foam (you can read that from the velocity of the cable, HY5 is 87%), low density makes it vulnerable to handling both in production and user handling.
Of course that gives lower looses.
Knud
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What connectors fit it? HF5 is 5.4mm. I've not found anything that fits it.
Risky maybe, but it worked better than those 3rd party crimp connectors. ;) Joking aside, it's a fast solder. It might take some practice, but really not bad.
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Ecoflex 5 from SSB electronic (Germany)
Belden H155 (Dutch)
LMR240 will also go in this category, maybe with a different outer ferrule
Connectors which fits these cables will also fits HY5
Same design multi core inner conductor, braid + foil shield, foam dielectric
It is jungle to navigate in which connector and crimp tool goes with which connector.
Some times is the connector housing the same but different center pin and different outer ferrule.
Luckily I have a supplier close to me which has a great variety of parts/cables and knowlegde in this area.
But it is interesting that you have clearly better results from HY5 than I have
I could be tempted to order a few meters and connectors...not very expensive here..out of curiosity
Knud
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That's funny. Despite my better results, I still want to try the crimp connectors. 🤦♂️
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The connectors is definitely not the difference over a such wide frequency range.
The cable is the guilty :)
So be happy that the HY5 works you ;)
May I got the last meters they produced before the weekend ;)
But in the low price segment the competition is hard....focus on low attenuation is a highlight "mine is faster than yours"
For VNA use this is secondary
Knud
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I disagree. I did a terrible job originally with the connectors, and didn't get those results until replacing them. ;)
The cable meets spec for me, and not for you. If it was the cable, it would not meet spec for either of us.
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I fully understand your deduction ;)
You made crappy connection got poor results, change to good connections get good results
Vice versa I get poor results...I must have made crappy connections ;)
What are against that conclusion:
I made 6 identical bad connections ....I am very good ;)
I have seen more poor cables than poor connections ;)
All my other crimped connections (close to 100) are ok
I believe it is more likely that I have got a length of "monday" cable
Knud
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The reason I don't agree with your deduction, is that the connectors are not specifically for 5.4mm cables. 5mm cables are common. I've not seen anybody else with 5.4mm. Frankly, it's silly. ;) Even if the connector kinda fits, we know that RF stuff is extra sensitive.
Please share a link to a specific 5.4mm N type crimp connector so we can see what it says about diameter and other details.
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https://www.reichelt.com/de/en/shop/product/n-plug_crimp_type_belden_h155_-280433 (https://www.reichelt.com/de/en/shop/product/n-plug_crimp_type_belden_h155_-280433)
Sorry German supplier
https://www.ecomponent.eu/connettore-n-maschio-a-crimpare-per-cavo-coassiale-belden-h155 (https://www.ecomponent.eu/connettore-n-maschio-a-crimpare-per-cavo-coassiale-belden-h155)
Italian
https://www.koax24.de/shop/article/n-stecker-gerade-crimpcrimp-020454.html (https://www.koax24.de/shop/article/n-stecker-gerade-crimpcrimp-020454.html)
German
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I always put a piece of shrinking tube with glue as a relief for the cable
Special important with cables like Hyperflex with thin braided shield combined with a foil shield
It cracks easily during use
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I don't know why
But no US brand's comes to my mind when we talk about RF connectors and cables
In old days Kings was a name...existing still ?
Radiall..UK or US ?..gone
Amphenol was a brand but hear nothing about them regarding serious RF coax connectors
cables...
German/EU serious brands, Hubert&Suhner, Spinner, Rosenberger
Times Microwave (amphenol I think)
A number of China/Taiwan brands very good price/performance
Italian brands always known for low-price
Knud
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Supposedly Gore cables HQ is in the US. I've not seen any cables better than that, but I'm sure some exist. ;)
I looked around, but it doesn't seem like I can get those connectors in the US at all.
ETA: Thanks for those links. I didn't know Belden H155 was also 5.4mm. Now I can try and find something through that.
ETA2: Belden H155A01 and M&P HF5 both have inner conductors at 1.4mm diameter, so in theory it should work. Maybe you need a better crimping tool. ;) ;)
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I don't know why
But no US brand's comes to my mind when we talk about RF connectors and cables
In old days Kings was a name...existing still ?
Radiall..UK or US ?..gone
Amphenol was a brand but hear nothing about them regarding serious RF coax connectors
cables...
German/EU serious brands, Hubert&Suhner, Spinner, Rosenberger
Times Microwave (amphenol I think)
A number of China/Taiwan brands very good price/performance
Italian brands always known for low-price
Knud
Amphenol bought Times Microwave, it's right on their website "an Amphenol company".
As far as US brands, Belden is a US brand, so is Molex, Pomona, Fairview Microwave, and I'm sure there are more. How many of them actually make their own products, I do not know.
When it comes to RF connectors, I trust Amphenol/Times Microwave stuff and if I can find them in stock, that's what I get.
Have good experience with H&S & Rosenberger, but they are less readily available in US.
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Supposedly Gore cables HQ is in the US. I've not seen any cables better than that, but I'm sure some exist. ;)
I looked around, but it doesn't seem like I can get those connectors in the US at all.
ETA: Thanks for those links. I didn't know Belden H155 was also 5.4mm. Now I can try and find something through that.
ETA2: Belden H155A01 and M&P HF5 both have inner conductors at 1.4mm diameter, so in theory it should work. Maybe you need a better crimping tool. ;) ;)
Gore are not only headquartered in US, but most of their high end cables are also made here.
Best cables I've ever come accross are Junkosha. But I can neither find them on ebay nor afford them new :-DD
Shahriar (The Signal Path) has couple of videos about high end cables. In one of them he demonstrates how good Junkosha cables are.
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Gore cables aren't cheap either. We're just luck to find them used on feeBay sometimes.
ETA: Here's one for ya: https://www.ebay.com/itm/332173190708 (https://www.ebay.com/itm/332173190708) let me know how it is. :-DD
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Gore cables aren't cheap either. We're just luck to find them used on feeBay sometimes.
ETA: Here's one for ya: https://www.ebay.com/itm/332173190708 (https://www.ebay.com/itm/332173190708) let me know how it is. :-DD
I know, but I've had more luck finding Gore for "reasonable" $$ than Junkosha.
The one you linked above is not quite the type of cable we are talking about.
Here are a couple of examples:
https://www.ebay.com/itm/187893200636 (https://www.ebay.com/itm/187893200636)
or
https://www.ebay.com/itm/263399824501 (https://www.ebay.com/itm/263399824501)
And both are shipped from outside of US.
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Hard pass at the pricing / importing. The second one's photos look like Gore's phaseflex sheathing.
Anyway, I don't need any cables. I didn't need all the Gore cables either...but at least they're awesome. :palm:
BTW- you'll see a few more options if you search just for Junflon.
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BTW- you'll see a few more options if search just for Junflon.
"Those are not the droids you are looking for" :-DD
They are the "commercial" grade cables/connectors.
Gore PhaseFlex (and Junkosha equivalent) are "instrument/metrology" grade cables/connectors.
Like I said previously, if I have to make cables myself, I just use RG400 with decent RG58 connectors (from either Amphenol or Times) for every day use/abuse.
For my ham radio stuff at home, I use Belden 9913F7 or Davis RF Bury-Flex (don't go higher than 500MHz there). RG400 in my vehicles.
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Ah, I see. The connectors are what seems to be the standout difference. Can't tell much about the coax from shitty ebay photos. ;)
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Yup. Gore does have DS that has all the information to decode their part numbers.
For example the last cable we (both) bought has the following part # OSZKUZKU036
OS - is the cable type
ZKU - is Type N male (Field Grade) connector (so both ends are N)
036 - is the lenght in inches
Part number for the higher grabe cable would be OUQ01Q01036
OU - cable type
Q01 - Type N male (Instrument Grade) connector
036 - lenght
P.S. I'm attaching the full datasheet bellow.
[attachurl=1]
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OS & OU are both 18GHz cables.
I also have a couple 0WD01D01048.0.
OW 26.5GHz
D01D01 3.5mm Male to 3.5mm Male
48.0 length
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Nice ;D
Almost all of my TE cables are N type, I have stayed away from buying SMA/3.5mm/2.92mm cables.
I'll go broke if I start branching out to other connector types :-DD
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Too late. :palm: :-DD
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It could look like the big brands have "divided" the market into there regions
Fx: If you go for serious cables/connectors (Not specific VNA ) in EU/Asia then
Hubert&Suhner, Spinner, Rosenberger...and you get your pocket emptied :)
I only heard about Gore cables, no experience
I am planning to make some test cables out of this:
https://www.rf-microwave.com/en/huber-suhner/enviroflex-400/coaxial-cable-enviroflex-400-50ohm-spex-5mm/ef400/ (https://www.rf-microwave.com/en/huber-suhner/enviroflex-400/coaxial-cable-enviroflex-400-50ohm-spex-5mm/ef400/)
Not cheap...
But good for test cables and robust over time.
Knud
I don't know why
But no US brand's comes to my mind when we talk about RF connectors and cables
In old days Kings was a name...existing still ?
Radiall..UK or US ?..gone
Amphenol was a brand but hear nothing about them regarding serious RF coax connectors
cables...
German/EU serious brands, Hubert&Suhner, Spinner, Rosenberger
Times Microwave (amphenol I think)
A number of China/Taiwan brands very good price/performance
Italian brands always known for low-price
Knud
Amphenol bought Times Microwave, it's right on their website "an Amphenol company".
As far as US brands, Belden is a US brand, so is Molex, Pomona, Fairview Microwave, and I'm sure there are more. How many of them actually make their own products, I do not know.
When it comes to RF connectors, I trust Amphenol/Times Microwave stuff and if I can find them in stock, that's what I get.
Have good experience with H&S & Rosenberger, but they are less readily available in US.
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Bit of a minefield this one isn't it. I guess I have to choose between, what's flexible and convenient for to be test leads and from what I can get. Maybe LRM195 (in that size and availability bracket) is the best for me out of all of these?
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I would choose a double braid shielded cable from a well known brand
Foil shielded cable is not my like for lab/bench use
Tend to crack over time.
A 5mm cable is a good compromise between stability versus flexibility
What upper frequency range ?
select a cable which is decent specified (not necessarily low atten.) also above your use frequency.
What can you get ?
Knud