23cm warm cable


militaryoperator
 

Ok, my new 23cm 100W set seems to be working but noticed the cable from amp to isolator is getting warm, its blue mini bend, and the cable from ant relay to socket on case wall, semi-rigid (0.086) is also warm. 

I'm going N to sma adapter, sma mini-bend to sma iso, iso is sma o/p to sma to N adp into relay, N to sma adp then semi rigid to N chassis socket.

What else can I use? RG402?  I could use N type soldered to RG402 to sma for Amp to Iso and  Soldered N RG402 to N and use a N to N bulkhead I guess. That would remove a couple of adaptors.

Ben


Geoff Newstead
 

Are you sure it’s not just conducted heat?

 

Sent from Mail for Windows 10

 

From: militaryoperator via groups.io
Sent: 03 March 2021 21:18
To: ukmicrowaves@groups.io
Subject: [UKMicrowaves] 23cm warm cable

 

Ok, my new 23cm 100W set seems to be working but noticed the cable from amp to isolator is getting warm, its blue mini bend, and the cable from ant relay to socket on case wall, semi-rigid (0.086) is also warm. 

 

I'm going N to sma adapter, sma mini-bend to sma iso, iso is sma o/p to sma to N adp into relay, N to sma adp then semi rigid to N chassis socket.

 

What else can I use? RG402?  I could use N type soldered to RG402 to sma for Amp to Iso and  Soldered N RG402 to N and use a N to N bulkhead I guess. That would remove a couple of adaptors.

 

Ben

 


militaryoperator
 


Are you sure it’s not just conducted heat?
 

It is, its conducting from inside the cable out. 


B


Andy G4JNT
 

You'd expect .086 SR to get warm at 100W of L-Band

Back in the days of playing with a K2RIW, I remember the thicker .141 SR gets warm at 400W of 432MHz
And the same stuff warms with 10W of 10GHz

You should be using .141 at that level / frequency



On Wed, 3 Mar 2021 at 21:18, militaryoperator via groups.io <Military1944=aol.com@groups.io> wrote:
Ok, my new 23cm 100W set seems to be working but noticed the cable from amp to isolator is getting warm, its blue mini bend, and the cable from ant relay to socket on case wall, semi-rigid (0.086) is also warm. 

I'm going N to sma adapter, sma mini-bend to sma iso, iso is sma o/p to sma to N adp into relay, N to sma adp then semi rigid to N chassis socket.

What else can I use? RG402?  I could use N type soldered to RG402 to sma for Amp to Iso and  Soldered N RG402 to N and use a N to N bulkhead I guess. That would remove a couple of adaptors.

Ben


ian hope (2E0IJH)
 

I remember melting a Rg213 patch lead with a K2RIW, BTW if anyone's got a neglected one laying about PM me
 
Ian
M5IJH

 
 
Sent: Wednesday, March 03, 2021 at 10:33 PM
From: "Andy G4JNT" <andy.g4jnt@...>
To: "UK Microwaves groups.io" <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] 23cm warm cable
You'd expect .086 SR to get warm at 100W of L-Band
 
Back in the days of playing with a K2RIW, I remember the thicker .141 SR gets warm at 400W of 432MHz
And the same stuff warms with 10W of 10GHz
 
You should be using .141 at that level / frequency
 
Andy
 
 
On Wed, 3 Mar 2021 at 21:18, militaryoperator via groups.io <Military1944=aol.com@groups.io> wrote:
Ok, my new 23cm 100W set seems to be working but noticed the cable from amp to isolator is getting warm, its blue mini bend, and the cable from ant relay to socket on case wall, semi-rigid (0.086) is also warm. 
 
I'm going N to sma adapter, sma mini-bend to sma iso, iso is sma o/p to sma to N adp into relay, N to sma adp then semi rigid to N chassis socket.
 
What else can I use? RG402?  I could use N type soldered to RG402 to sma for Amp to Iso and  Soldered N RG402 to N and use a N to N bulkhead I guess. That would remove a couple of adaptors.
 
Ben

 

 


Andy G4JNT
 

To be a bit more scientific about it :

Loss in  .086 Simi Rigid is  0.73dB / metre at 1296MHz.   SO in a 100mm length, that's   1 - 10^(-.0073)   = 0.0167 of the input power dissipated.

At 100 Watts that's 1.7 Watts dissipated in 100mm of cable.   You'd expect it to be getting warm




On Wed, 3 Mar 2021 at 22:45, ian hope (2E0IJH) <ian@...> wrote:
I remember melting a Rg213 patch lead with a K2RIW, BTW if anyone's got a neglected one laying about PM me
 
Ian
M5IJH
 
 
Sent: Wednesday, March 03, 2021 at 10:33 PM
From: "Andy G4JNT" <andy.g4jnt@...>
To: "UK Microwaves groups.io" <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] 23cm warm cable
You'd expect .086 SR to get warm at 100W of L-Band
 
Back in the days of playing with a K2RIW, I remember the thicker .141 SR gets warm at 400W of 432MHz
And the same stuff warms with 10W of 10GHz
 
You should be using .141 at that level / frequency
 
Andy
 
 
On Wed, 3 Mar 2021 at 21:18, militaryoperator via groups.io <Military1944=aol.com@groups.io> wrote:
Ok, my new 23cm 100W set seems to be working but noticed the cable from amp to isolator is getting warm, its blue mini bend, and the cable from ant relay to socket on case wall, semi-rigid (0.086) is also warm. 
 
I'm going N to sma adapter, sma mini-bend to sma iso, iso is sma o/p to sma to N adp into relay, N to sma adp then semi rigid to N chassis socket.
 
What else can I use? RG402?  I could use N type soldered to RG402 to sma for Amp to Iso and  Soldered N RG402 to N and use a N to N bulkhead I guess. That would remove a couple of adaptors.
 
Ben

 

 


Phil Guttridge G3TCU
 

I find 0.25" semi-rigid (real RG401) gets warm at 400W on 23cm.

73, Phil. G3TCU



On 03/03/2021 22:55, Andy G4JNT via groups.io wrote:
To be a bit more scientific about it :

Loss in  .086 Simi Rigid is  0.73dB / metre at 1296MHz.   SO in a 100mm length, that's   1 - 10^(-.0073)   = 0.0167 of the input power dissipated.

At 100 Watts that's 1.7 Watts dissipated in 100mm of cable.   You'd expect it to be getting warm




On Wed, 3 Mar 2021 at 22:45, ian hope (2E0IJH) <ian@...> wrote:
I remember melting a Rg213 patch lead with a K2RIW, BTW if anyone's got a neglected one laying about PM me
 
Ian
M5IJH
 
 
Sent: Wednesday, March 03, 2021 at 10:33 PM
From: "Andy G4JNT" <andy.g4jnt@...>
To: "UK Microwaves groups.io" <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] 23cm warm cable
You'd expect .086 SR to get warm at 100W of L-Band
 
Back in the days of playing with a K2RIW, I remember the thicker .141 SR gets warm at 400W of 432MHz
And the same stuff warms with 10W of 10GHz
 
You should be using .141 at that level / frequency
 
Andy
 
 
On Wed, 3 Mar 2021 at 21:18, militaryoperator via groups.io <Military1944=aol.com@groups.io> wrote:
Ok, my new 23cm 100W set seems to be working but noticed the cable from amp to isolator is getting warm, its blue mini bend, and the cable from ant relay to socket on case wall, semi-rigid (0.086) is also warm. 
 
I'm going N to sma adapter, sma mini-bend to sma iso, iso is sma o/p to sma to N adp into relay, N to sma adp then semi rigid to N chassis socket.
 
What else can I use? RG402?  I could use N type soldered to RG402 to sma for Amp to Iso and  Soldered N RG402 to N and use a N to N bulkhead I guess. That would remove a couple of adaptors.
 
Ben

 

 


Virus-free. www.avg.com


militaryoperator
 


You should be using .141 at that level / frequency

Andy


Yes, I guessed that Andy.I can see N plugs on ebay but couldn't see any cable, will keep searching. 

Thanks, Ben. 


Rien Eradus PA0JME
 

Hi all,

My experience 0.25 inch at 1296MHz and 120 Watt RF is OK, it certainly is better since 0.141 will become to hot too

Short ends (20 to 30cms) can be found at fleamarkets, often used as phasing lines in antenna's for UMTS and the like

Pityfull fleamarkets are far from common at the moment, I know

Aliexpress also supplies new cable RG401, though not really cheap (around USD18/m), and waiting time can be long

Best regards Rien PA0JME

Op 4-3-2021 om 12:53 schreef militaryoperator via groups.io:


You should be using .141 at that level / frequency

Andy


Yes, I guessed that Andy.I can see N plugs on ebay but couldn't see any cable, will keep searching. 

Thanks, Ben.