COAXIAL CABLE LMR400


Martin
 

Could I ask for some information on LMR 400 coaxial cable from anyone who has used it and how it turns out in practise. 
I gather from what I have read, that its good quality and fairly low loss when compared with the other 10 mm approx. diameter cables. I am looking for something for use on 23 cms and will be using half inch LDF4-50A for the main run from shack to tower base and something more flexible from there on, around say another 45 feet. I will be running an LNA at the top and close to the Yagi.
I cannot see that it is available from the main amateur radio dealers and there is one commercial supplier who will only provide it in 100 m drums.  I am happy to invest a in this quantity, (for other purposes and bands) but not until I know more about the cable itself. Does it require special N series plugs and how flexible is it etc? Its available on eBay I think but again, reading seems to suggest there is some dubious quality cable being sold which is fake?      


John Quarmby
 

There are a lot of clones around, some better than others, in my experience it is best to avoid eBay, having encountered a clone where the aluminium shield did not enclose the whole circumference of the dielectric. If you are including a turning loop at the top of the tower then go for LMR400UF which has a stranded copper inner conductor and will last longer, but it does have slightly higher loss.

I have used Gigatronix to make up cables with crimp connectors and suitable strain relief, using their LBC400ExtraFlex equivalent. After 6 years I am just about to replace one of the masthead cables as the inner of the N socket at the top is now badly worn from changing antennas every week, all their other coax jumpers up there are still going strong.

They have a useful ordering tool where you can try various connector and cable options:

https://www.gigatronix.co.uk/cabulator/coaxial/cable-type

73

John G3XDY

On 08/05/2021 20:26, Martin wrote:
Could I ask for some information on LMR 400 coaxial cable from anyone who has used it and how it turns out in practise. 
I gather from what I have read, that its good quality and fairly low loss when compared with the other 10 mm approx. diameter cables. I am looking for something for use on 23 cms and will be using half inch LDF4-50A for the main run from shack to tower base and something more flexible from there on, around say another 45 feet. I will be running an LNA at the top and close to the Yagi.
I cannot see that it is available from the main amateur radio dealers and there is one commercial supplier who will only provide it in 100 m drums.  I am happy to invest a in this quantity, (for other purposes and bands) but not until I know more about the cable itself. Does it require special N series plugs and how flexible is it etc? Its available on eBay I think but again, reading seems to suggest there is some dubious quality cable being sold which is fake?      

Virus-free. www.avast.com


ian hope (2E0IJH)
 

We use drums and drums of a Clone from WIFI antennas, it uses slightly larger centre pin than Rg213, we buy plugs from M0MAT on ebay, 
 
https://www.wifi-antennas.co.uk/hdf400-coaxial-cable-100m-drum
 
It is quite stiff, but not as bad as LDF, you can a flexible version for rotator loops
 
Hope that helps 
 
Ian
M5IJH

 
 
Sent: Saturday, May 08, 2021 at 9:26 PM
From: "Martin" <gw3xjq@...>
To: UKMicrowaves@groups.io
Subject: [UKMicrowaves] COAXIAL CABLE LMR400
Could I ask for some information on LMR 400 coaxial cable from anyone who has used it and how it turns out in practise. 
I gather from what I have read, that its good quality and fairly low loss when compared with the other 10 mm approx. diameter cables. I am looking for something for use on 23 cms and will be using half inch LDF4-50A for the main run from shack to tower base and something more flexible from there on, around say another 45 feet. I will be running an LNA at the top and close to the Yagi.
I cannot see that it is available from the main amateur radio dealers and there is one commercial supplier who will only provide it in 100 m drums.  I am happy to invest a in this quantity, (for other purposes and bands) but not until I know more about the cable itself. Does it require special N series plugs and how flexible is it etc? Its available on eBay I think but again, reading seems to suggest there is some dubious quality cable being sold which is fake?      


John Lemay
 

Martin

LMR-400 is not very flexible and whilst it will be fine for running up the tower, it is less suitable for a rotator loop - unless you form it in a helix of a couple of turns. FWIW I run LDF4-50 up the tower to the head unit and then use flexible cables at the rotator.

Reliable names to look out for are Times Microwave and Commscope. As others have said, you may or may not get good performance from the many clones that are available. DX Shop is one UK source.

Yes, you will need connectors which are specific to LMR-400.

Regards

John G4ZTR

On 2021-05-08 21:26, Martin wrote:
Could I ask for some information on LMR 400 coaxial cable from anyone
who has used it and how it turns out in practise.
I gather from what I have read, that its good quality and fairly low
loss when compared with the other 10 mm approx. diameter cables. I am
looking for something for use on 23 cms and will be using half inch
LDF4-50A for the main run from shack to tower base and something more
flexible from there on, around say another 45 feet. I will be running
an LNA at the top and close to the Yagi.
I cannot see that it is available from the main amateur radio dealers
and there is one commercial supplier who will only provide it in 100 m
drums. I am happy to invest a in this quantity, (for other purposes
and bands) but not until I know more about the cable itself. Does it
require special N series plugs and how flexible is it etc? Its
available on eBay I think but again, reading seems to suggest there is
some dubious quality cable being sold which is fake?
Links:
------
[1] https://groups.io/g/UKMicrowaves/message/62381
[2] https://groups.io/mt/82686040/239367
[3] https://groups.io/g/UKMicrowaves/post
[4] https://groups.io/g/UKMicrowaves/editsub/239367
[5] https://groups.io/g/UKMicrowaves/leave/3272144/239367/1480192407/xyzzy


Dave G6HEF
 

Hi Martin,

I have recently installed LDF4-50 and used CNT-400, the Commscope equivalent of LMR400, for rotator loops. All available Through DX shop, who supply connectors and will fit at no extra cost if you are confident of the lengths you require.

I know lower cost connectors are available and M0MAT is a go-to, although the official connectors are just that little bit better. Whether or not the extra costs of the official ones justifies the extra costs are a
matter of personal choice.

I spent a lot of time thinking about how to engineer my installation and to be honest only time will tell how long the cables will withstand the flexing. I suspect there will still be lessons learnt at this QTH!

Hope that helps

Dave
G6HEF


ian hope (2E0IJH)
 

Yes there are some Poor clones, But I can safely state the clones from Wifi Antennas HDF 400 and the Clones from CCS LLA400, work well apear very similar in construction to LMR400 (TIMES) and have survived Contest Use.
Works out about £1 a meter for clones, from these sources, So is almost throw away feeder if damaged.
 
Ian
M5IJH

 
 
Sent: Sunday, May 09, 2021 at 8:56 AM
From: "John Lemay" <john@...>
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] COAXIAL CABLE LMR400
Martin

LMR-400 is not very flexible and whilst it will be fine for running up
the tower, it is less suitable for a rotator loop - unless you form it
in a helix of a couple of turns. FWIW I run LDF4-50 up the tower to the
head unit and then use flexible cables at the rotator.

Reliable names to look out for are Times Microwave and Commscope. As
others have said, you may or may not get good performance from the many
clones that are available. DX Shop is one UK source.

Yes, you will need connectors which are specific to LMR-400.

Regards

John G4ZTR

On 2021-05-08 21:26, Martin wrote:
> Could I ask for some information on LMR 400 coaxial cable from anyone
> who has used it and how it turns out in practise.
> I gather from what I have read, that its good quality and fairly low
> loss when compared with the other 10 mm approx. diameter cables. I am
> looking for something for use on 23 cms and will be using half inch
> LDF4-50A for the main run from shack to tower base and something more
> flexible from there on, around say another 45 feet. I will be running
> an LNA at the top and close to the Yagi.
> I cannot see that it is available from the main amateur radio dealers
> and there is one commercial supplier who will only provide it in 100 m
> drums. I am happy to invest a in this quantity, (for other purposes
> and bands) but not until I know more about the cable itself. Does it
> require special N series plugs and how flexible is it etc? Its
> available on eBay I think but again, reading seems to suggest there is
> some dubious quality cable being sold which is fake?
>
>
> Links:
> ------
> [1] https://groups.io/g/UKMicrowaves/message/62381
> [2] https://groups.io/mt/82686040/239367
> [3] https://groups.io/g/UKMicrowaves/post
> [4] https://groups.io/g/UKMicrowaves/editsub/239367
> [5]
> https://groups.io/g/UKMicrowaves/leave/3272144/239367/1480192407/xyzzy




 


alwyn.seeds1
 

Dear Martin,

If you need flexibility for rotator loops, then LMR400-UF rather than LMR400 is what you need.

There are many clones, some good, some bad, as others have commented. Foam dielectric cables are not easy to make as fluctuations in foam density in extrusion cause fluctuations in characteristic impedance. Look at the swept frequency return loss, if the manufacturer dares publish it. Of course some manufacturers publish data but the actual cable performance falls short of what is published.

I find that LMR400-UF works quite well for rotator loops, provided these are designed with no sharp bends- the foam in LMR400-UF is denser than in some of the alternative cables, so that displacement of the inner conductor with repeated flexure is less of a problem. I have loops that are getting on for 10 years old and still work fine at frequencies up to 1298 MHz.

Times Microwave, which is a subsidiary of Commscope, also have a MIL-SPEC flexible tactical cable series, that has a special tape shielding which is more suitable for repeated flexure than the bonded foil used in LMR400-UF- I am awaiting pricing details for this. It will probably be quite expensive as conductors are silver plated, construction is complex plus there are the extra quality control costs to retain a MIL-SPEC approval.

Regards,

Alwyn G8DOH
_____________________________________________________

Alwyn Seeds, Director
SynOptika Ltd.,
114 Beaufort Street,
London,
SW3 6BU,
England.


SynOptika Ltd., Registered in England and Wales: No. 04606737
Registered Office: 114 Beaufort Street, London, SW3 6BU, United Kingdom.
_____________________________________________________


Reg Woolley
 

I agree many use FSJ 4 50.however that has a very fragile outer jacket and can easily be rubbed away.

Reg g8vhi 



Sent from my Samsung Galaxy S10e - Powered by Three


-------- Original message --------
From: "alwyn.seeds1" <a.seeds@...>
Date: 09/05/2021 10:28 (GMT+00:00)
To: "UK Microwaves groups.io" <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] COAXIAL CABLE LMR400

Dear Martin,

If you need flexibility for rotator loops, then LMR400-UF rather than LMR400 is what you need.

There are many clones, some good, some bad, as others have commented. Foam dielectric cables are not easy to make as fluctuations in foam density in extrusion cause fluctuations in characteristic impedance. Look at the swept frequency return loss, if the manufacturer dares publish it. Of course some manufacturers publish data but the actual cable performance falls short of what is published.

I find that LMR400-UF works quite well for rotator loops, provided these are designed with no sharp bends- the foam in LMR400-UF is denser than in some of the alternative cables, so that displacement of the inner conductor with repeated flexure is less of a problem. I have loops that are getting on for 10 years old and still work fine at frequencies up to 1298 MHz.

Times Microwave, which is a subsidiary of Commscope, also have a MIL-SPEC flexible tactical cable series, that has a special tape shielding which is more suitable for repeated flexure than the bonded foil used in LMR400-UF- I am awaiting pricing details for this. It will probably be quite expensive as conductors are silver plated, construction is complex plus there are the extra quality control costs to retain a MIL-SPEC approval.

Regards,

Alwyn G8DOH
_____________________________________________________

Alwyn Seeds, Director
SynOptika Ltd.,
114 Beaufort Street,
London,
SW3 6BU,
England.


SynOptika Ltd., Registered in England and Wales: No. 04606737
Registered Office: 114 Beaufort Street, London, SW3 6BU, United Kingdom.
_____________________________________________________


Pete - GM4BYF
 

I am using Unispectra S400 for connection round a rotator. No problems so far. 0.167 dB loss per metre.

73
Pete GM4BYF
On 08/05/21 21:26, Martin wrote:

Could I ask for some information on LMR 400 coaxial cable from anyone who has used it and how it turns out in practise. 
I gather from what I have read, that its good quality and fairly low loss when compared with the other 10 mm approx. diameter cables. I am looking for something for use on 23 cms and will be using half inch LDF4-50A for the main run from shack to tower base and something more flexible from there on, around say another 45 feet. I will be running an LNA at the top and close to the Yagi.
I cannot see that it is available from the main amateur radio dealers and there is one commercial supplier who will only provide it in 100 m drums.  I am happy to invest a in this quantity, (for other purposes and bands) but not until I know more about the cable itself. Does it require special N series plugs and how flexible is it etc? Its available on eBay I think but again, reading seems to suggest there is some dubious quality cable being sold which is fake?      

--
vry 73
Pete GM4BYF


Conrad, PA5Y
 

Over here there is lots of RFS cable and hardly any Commscope. LMR cables are far too expensive.  I have loops of SCF12-50J and also run it up the tower, so far so good. Including VAT both LCF12-50 and SCF12-50 is 3.70 EUR per meter and Spinner N types are 11.70 EUR each, 7/16 about the same. This is genuine cable and high quality. I no longer use any amateur cables as it is 2-3 times more expensive and about 1/4 as good. As I have 360 deg of good take off I rotate my antennas a lot and I am quite active. Therefore I believe that these cables are up to the task.

Regards

Conrad PA5Y


From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> on behalf of John Lemay via groups.io <john@...>
Sent: 09 May 2021 09:56
To: UKMicrowaves@groups.io <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] COAXIAL CABLE LMR400
 
Martin

LMR-400 is not very flexible and whilst it will be fine for running up
the tower, it is less suitable for a rotator loop - unless you form it
in a helix of a couple of turns. FWIW I run LDF4-50 up the tower to the
head unit and then use flexible cables at the rotator.

Reliable names to look out for are Times Microwave and Commscope. As
others have said, you may or may not get good performance from the many
clones that are available. DX Shop is one UK source.

Yes, you will need connectors which are specific to LMR-400.

Regards

John G4ZTR

On 2021-05-08 21:26, Martin wrote:
> Could I ask for some information on LMR 400 coaxial cable from anyone
> who has used it and how it turns out in practise.
> I gather from what I have read, that its good quality and fairly low
> loss when compared with the other 10 mm approx. diameter cables. I am
> looking for something for use on 23 cms and will be using half inch
> LDF4-50A for the main run from shack to tower base and something more
> flexible from there on, around say another 45 feet. I will be running
> an LNA at the top and close to the Yagi.
> I cannot see that it is available from the main amateur radio dealers
> and there is one commercial supplier who will only provide it in 100 m
> drums.  I am happy to invest a in this quantity, (for other purposes
> and bands) but not until I know more about the cable itself. Does it
> require special N series plugs and how flexible is it etc? Its
> available on eBay I think but again, reading seems to suggest there is
> some dubious quality cable being sold which is fake?
>
>
> Links:
> ------
> [1] https://groups.io/g/UKMicrowaves/message/62381
> [2] https://groups.io/mt/82686040/239367
> [3] https://groups.io/g/UKMicrowaves/post
> [4] https://groups.io/g/UKMicrowaves/editsub/239367
> [5]
> https://groups.io/g/UKMicrowaves/leave/3272144/239367/1480192407/xyzzy






Martin
 

Many thanks to everyone for such a response, I certainly have much information now, but possibly a little confused? I really appreciate all the comments from you all who have been here and done it all before.  
I have checked the losses at 1296 MHz and whilst I realise there is more to this than meets the eye in terms of quality, flexibility and expected lifespan; my conclusion is that LMR 400 is about 1 dB  better than the M and P Ultraflex 10 and that the M and P 13 mm one is 3 .7 dBs better than LMR 400, which is a useful bonus if accurate specification.  All compared to LDF4-50A at 8.9 dBs per 100 metres around 6 dB's better than the LMR400. Its getting around the rotator that's the 'problem' as has always been difficult but more so, when considering 23 cms. The LMR cable flexible can only be purchased in 300 m coils I think and is rather expensive! Using an LNA/PA (S G Labs) suppose the losses give or take a dB will not be too critical? So its a case of balancing the budget against performance required/expected. 73 Martin GW3XJQ     
  


Clive, G3GJA
 

You can buy LLA400UF in 1m increments here: LLA400UF® ULTRA FLEX Coaxial Cable - 1M INCREMENTS (ccsukltd.co.uk) That is what I shall be using for my rotator loops.

 

The LLA400 clone has a much tougher jacket than some of the other clones, such as HDF400, and the measured performance of four 25m lengths used on a local repeater site matched the published LMR400 performance at 23cms. More than can be said for a new 100m drum of  Westflex 103 which was awful.

 

Clive G3GJA

 

From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> On Behalf Of Martin
Sent: 10 May 2021 17:04
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] COAXIAL CABLE LMR400

 

Many thanks to everyone for such a response, I certainly have much information now, but possibly a little confused? I really appreciate all the comments from you all who have been here and done it all before.  
I have checked the losses at 1296 MHz and whilst I realise there is more to this than meets the eye in terms of quality, flexibility and expected lifespan; my conclusion is that LMR 400 is about 1 dB  better than the M and P Ultraflex 10 and that the M and P 13 mm one is 3 .7 dBs better than LMR 400, which is a useful bonus if accurate specification.  All compared to LDF4-50A at 8.9 dBs per 100 metres around 6 dB's better than the LMR400. Its getting around the rotator that's the 'problem' as has always been difficult but more so, when considering 23 cms. The LMR cable flexible can only be purchased in 300 m coils I think and is rather expensive! Using an LNA/PA (S G Labs) suppose the losses give or take a dB will not be too critical? So its a case of balancing the budget against performance required/expected. 73 Martin GW3XJQ     
  



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HESH Computer Services

hesh.co.uk
01482 324936

8 Louis Pearlman Centre, Goulton Street, Hull, HU3 4DL

Registered in England No. 3003479. The information contained in this email may be legally privileged and/or confidential. If you are not the intended recipient, use of this information (including disclosure, copying or distribution) or any action taken, or omitted to be taken, in reliance on it is prohibited and may be unlawful; therefore please inform the sender and delete the message immediately. The views expressed in this email are those of the originator and not necessarily those held by HESH Computer Services Ltd, who do not accept liability for any action taken in reliance on the contents of this message or for the consequences of any computer viruses which may have been transmitted by this email.


Colin Ranson
 

Thanks for that info Clive,   a swift look did not reveal carriage for say - 12m,

 

Any idea ? Our club antennas could do with some decent stuff.

 

Regards

 

Colin de G8LBS

 

Sent from Mail for Windows 10

 

From: Clive, G3GJA
Sent: 10 May 2021 17:26
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] COAXIAL CABLE LMR400

 

You can buy LLA400UF in 1m increments here: LLA400UF® ULTRA FLEX Coaxial Cable - 1M INCREMENTS (ccsukltd.co.uk) That is what I shall be using for my rotator loops.

 

The LLA400 clone has a much tougher jacket than some of the other clones, such as HDF400, and the measured performance of four 25m lengths used on a local repeater site matched the published LMR400 performance at 23cms. More than can be said for a new 100m drum of  Westflex 103 which was awful.

 

Clive G3GJA

 

From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> On Behalf Of Martin
Sent: 10 May 2021 17:04
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] COAXIAL CABLE LMR400

 

Many thanks to everyone for such a response, I certainly have much information now, but possibly a little confused? I really appreciate all the comments from you all who have been here and done it all before.  
I have checked the losses at 1296 MHz and whilst I realise there is more to this than meets the eye in terms of quality, flexibility and expected lifespan; my conclusion is that LMR 400 is about 1 dB  better than the M and P Ultraflex 10 and that the M and P 13 mm one is 3 .7 dBs better than LMR 400, which is a useful bonus if accurate specification.  All compared to LDF4-50A at 8.9 dBs per 100 metres around 6 dB's better than the LMR400. Its getting around the rotator that's the 'problem' as has always been difficult but more so, when considering 23 cms. The LMR cable flexible can only be purchased in 300 m coils I think and is rather expensive! Using an LNA/PA (S G Labs) suppose the losses give or take a dB will not be too critical? So its a case of balancing the budget against performance required/expected. 73 Martin GW3XJQ     
  

 

HESH Typographic Logo

HESH Computer Services

hesh.co.uk
01482 324936

8 Louis Pearlman Centre, Goulton Street, Hull, HU3 4DL

 

Registered in England No. 3003479. The information contained in this email may be legally privileged and/or confidential. If you are not the intended recipient, use of this information (including disclosure, copying or distribution) or any action taken, or omitted to be taken, in reliance on it is prohibited and may be unlawful; therefore please inform the sender and delete the message immediately. The views expressed in this email are those of the originator and not necessarily those held by HESH Computer Services Ltd, who do not accept liability for any action taken in reliance on the contents of this message or for the consequences of any computer viruses which may have been transmitted by this email.

 


Colin Ranson
 

Oh, forgot to mention, the M+P 13mm is relatively like lead piping to bend compared to M+P hyperflex, at least the example I’ve seem, but jolly good for straight runs.

 

Colin de G8LBS.

 

Sent from Mail for Windows 10

 

From: Colin Ranson
Sent: 10 May 2021 17:36
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] COAXIAL CABLE LMR400

 

Thanks for that info Clive,   a swift look did not reveal carriage for say - 12m,

 

Any idea ? Our club antennas could do with some decent stuff.

 

Regards

 

Colin de G8LBS

 

Sent from Mail for Windows 10

 

From: Clive, G3GJA
Sent: 10 May 2021 17:26
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] COAXIAL CABLE LMR400

 

You can buy LLA400UF in 1m increments here: LLA400UF® ULTRA FLEX Coaxial Cable - 1M INCREMENTS (ccsukltd.co.uk) That is what I shall be using for my rotator loops.

 

The LLA400 clone has a much tougher jacket than some of the other clones, such as HDF400, and the measured performance of four 25m lengths used on a local repeater site matched the published LMR400 performance at 23cms. More than can be said for a new 100m drum of  Westflex 103 which was awful.

 

Clive G3GJA

 

From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> On Behalf Of Martin
Sent: 10 May 2021 17:04
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] COAXIAL CABLE LMR400

 

Many thanks to everyone for such a response, I certainly have much information now, but possibly a little confused? I really appreciate all the comments from you all who have been here and done it all before.  
I have checked the losses at 1296 MHz and whilst I realise there is more to this than meets the eye in terms of quality, flexibility and expected lifespan; my conclusion is that LMR 400 is about 1 dB  better than the M and P Ultraflex 10 and that the M and P 13 mm one is 3 .7 dBs better than LMR 400, which is a useful bonus if accurate specification.  All compared to LDF4-50A at 8.9 dBs per 100 metres around 6 dB's better than the LMR400. Its getting around the rotator that's the 'problem' as has always been difficult but more so, when considering 23 cms. The LMR cable flexible can only be purchased in 300 m coils I think and is rather expensive! Using an LNA/PA (S G Labs) suppose the losses give or take a dB will not be too critical? So its a case of balancing the budget against performance required/expected. 73 Martin GW3XJQ     
  

 

HESH Typographic Logo

HESH Computer Services

hesh.co.uk
01482 324936

8 Louis Pearlman Centre, Goulton Street, Hull, HU3 4DL

 

Registered in England No. 3003479. The information contained in this email may be legally privileged and/or confidential. If you are not the intended recipient, use of this information (including disclosure, copying or distribution) or any action taken, or omitted to be taken, in reliance on it is prohibited and may be unlawful; therefore please inform the sender and delete the message immediately. The views expressed in this email are those of the originator and not necessarily those held by HESH Computer Services Ltd, who do not accept liability for any action taken in reliance on the contents of this message or for the consequences of any computer viruses which may have been transmitted by this email.

 

 


ian hope (2E0IJH)
 

CCS will sell there version of LMR 400 Flexible in Metre lengths, https://ccsukltd.co.uk/LMR400UF-ULTRAFLEX-Coaxial-Cable-LLA400UF-1M-INCREMENTS
 
And in My opinion it's as good as the Times stuff, if it survives contest use with us, it will be fine for home or normal portable
 
Ian
M5IJH

 
 
Sent: Monday, May 10, 2021 at 5:04 PM
From: "Martin" <gw3xjq@...>
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] COAXIAL CABLE LMR400
Many thanks to everyone for such a response, I certainly have much information now, but possibly a little confused? I really appreciate all the comments from you all who have been here and done it all before.  
I have checked the losses at 1296 MHz and whilst I realise there is more to this than meets the eye in terms of quality, flexibility and expected lifespan; my conclusion is that LMR 400 is about 1 dB  better than the M and P Ultraflex 10 and that the M and P 13 mm one is 3 .7 dBs better than LMR 400, which is a useful bonus if accurate specification.  All compared to LDF4-50A at 8.9 dBs per 100 metres around 6 dB's better than the LMR400. Its getting around the rotator that's the 'problem' as has always been difficult but more so, when considering 23 cms. The LMR cable flexible can only be purchased in 300 m coils I think and is rather expensive! Using an LNA/PA (S G Labs) suppose the losses give or take a dB will not be too critical? So its a case of balancing the budget against performance required/expected. 73 Martin GW3XJQ     
  


Raymond Brooks
 

Hi I'm interested in using LMR400 or equivalent on my mast as I can't find connectors for FSJ2-50. Has anyone used it above 5GHz and is so what sort of losses?

On 9 May 2021 11:51 am, "Reg Woolley via groups.io" <g8vhi@...> wrote:
I agree many use FSJ 4 50.however that has a very fragile outer jacket and can easily be rubbed away.

Reg g8vhi 



Sent from my Samsung Galaxy S10e - Powered by Three


-------- Original message --------
From: "alwyn.seeds1" <a.seeds@...>
Date: 09/05/2021 10:28 (GMT+00:00)
To: "UK Microwaves groups.io" <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] COAXIAL CABLE LMR400

Dear Martin,

If you need flexibility for rotator loops, then LMR400-UF rather than LMR400 is what you need.

There are many clones, some good, some bad, as others have commented. Foam dielectric cables are not easy to make as fluctuations in foam density in extrusion cause fluctuations in characteristic impedance. Look at the swept frequency return loss, if the manufacturer dares publish it. Of course some manufacturers publish data but the actual cable performance falls short of what is published.

I find that LMR400-UF works quite well for rotator loops, provided these are designed with no sharp bends- the foam in LMR400-UF is denser than in some of the alternative cables, so that displacement of the inner conductor with repeated flexure is less of a problem. I have loops that are getting on for 10 years old and still work fine at frequencies up to 1298 MHz.

Times Microwave, which is a subsidiary of Commscope, also have a MIL-SPEC flexible tactical cable series, that has a special tape shielding which is more suitable for repeated flexure than the bonded foil used in LMR400-UF- I am awaiting pricing details for this. It will probably be quite expensive as conductors are silver plated, construction is complex plus there are the extra quality control costs to retain a MIL-SPEC approval.

Regards,

Alwyn G8DOH
_____________________________________________________

Alwyn Seeds, Director
SynOptika Ltd.,
114 Beaufort Street,
London,
SW3 6BU,
England.


SynOptika Ltd., Registered in England and Wales: No. 04606737
Registered Office: 114 Beaufort Street, London, SW3 6BU, United Kingdom.
_____________________________________________________



--
Raymond G8KPS


Reg Woolley
 

Maybe Ralph  R-halliday@.... has some.  You could ask him

Reg G8VHI 



Sent from my Samsung Galaxy S10e - Powered by Three


-------- Original message --------
From: Raymond Brooks <g8kps@...>
Date: 11/05/2021 15:28 (GMT+00:00)
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] COAXIAL CABLE LMR400

Hi I'm interested in using LMR400 or equivalent on my mast as I can't find connectors for FSJ2-50. Has anyone used it above 5GHz and is so what sort of losses?

On 9 May 2021 11:51 am, "Reg Woolley via groups.io" <g8vhi@...> wrote:
I agree many use FSJ 4 50.however that has a very fragile outer jacket and can easily be rubbed away.

Reg g8vhi 



Sent from my Samsung Galaxy S10e - Powered by Three


-------- Original message --------
From: "alwyn.seeds1" <a.seeds@...>
Date: 09/05/2021 10:28 (GMT+00:00)
To: "UK Microwaves groups.io" <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] COAXIAL CABLE LMR400

Dear Martin,

If you need flexibility for rotator loops, then LMR400-UF rather than LMR400 is what you need.

There are many clones, some good, some bad, as others have commented. Foam dielectric cables are not easy to make as fluctuations in foam density in extrusion cause fluctuations in characteristic impedance. Look at the swept frequency return loss, if the manufacturer dares publish it. Of course some manufacturers publish data but the actual cable performance falls short of what is published.

I find that LMR400-UF works quite well for rotator loops, provided these are designed with no sharp bends- the foam in LMR400-UF is denser than in some of the alternative cables, so that displacement of the inner conductor with repeated flexure is less of a problem. I have loops that are getting on for 10 years old and still work fine at frequencies up to 1298 MHz.

Times Microwave, which is a subsidiary of Commscope, also have a MIL-SPEC flexible tactical cable series, that has a special tape shielding which is more suitable for repeated flexure than the bonded foil used in LMR400-UF- I am awaiting pricing details for this. It will probably be quite expensive as conductors are silver plated, construction is complex plus there are the extra quality control costs to retain a MIL-SPEC approval.

Regards,

Alwyn G8DOH
_____________________________________________________

Alwyn Seeds, Director
SynOptika Ltd.,
114 Beaufort Street,
London,
SW3 6BU,
England.


SynOptika Ltd., Registered in England and Wales: No. 04606737
Registered Office: 114 Beaufort Street, London, SW3 6BU, United Kingdom.
_____________________________________________________



--
Raymond G8KPS


Graham G3TCT
 

I'm using Hyperflex 10 for the rx line and Ultraflex 13 for the tx line on 23cm. The 13cm stuff is ok, mine isn't a problem re flexibility. 
I'm puzzled by the claim that LMR400 is better. The calculator at times* gives the attenuation of LMR400UF at 1296 as 18.7dB/100m and LMR400 as 15.5dB/100m, whilst M&P claim for HF10 is 15.49, so nothing in it unless you want the flexible type in which case M&P is better.  I've measured the M&P cables and they do seem to meet the spec AFAICT.

*  https://www.timesmicrowave.com/Calculator
73
Graham


Dave G6HEF
 

Hi Graham,

All any of us can do is gain from experience. I have no definite knowledge of the flex-durability of HF10. I can say that with Westflex 103 the foil is very liable to fracture, but I don't think anyone serious uses it anymore anyway?. Is HF10 better? our anecdotal knowledge here suggests not.

LMR400/CNT400 isn't as flexible at first sight but seems to have a better flex-durability in reasonably sized loops.

I should get hold of some HF10 and do a proper evaluation.

Dave
G6HEF


ian hope (2E0IJH)
 

Never done any tests with hyperflex, but have experience of foil cracks on ecoflex and it degrades very quickly once cracks apear in the foil
 
Ian
M5IJH

 
 
Sent: Wednesday, May 12, 2021 at 1:52 PM
From: "Dave G6HEF" <hardknottdave@...>
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] COAXIAL CABLE LMR400
Hi Graham,

All any of us can do is gain from experience. I have no definite knowledge of the flex-durability of HF10. I can say that with Westflex 103 the foil is very liable to fracture, but I don't think anyone serious uses it anymore anyway?. Is HF10 better? our anecdotal knowledge here suggests not.

LMR400/CNT400 isn't as flexible at first sight but seems to have a better flex-durability in reasonably sized loops.

I should get hold of some HF10 and do a proper evaluation.

Dave
G6HEF