Topics

FS: Transco Y Relay


Christopher Bartram <cbartram@...>
 

This relay has hung about, unused by me, for approachin four decades. If you don't know the Y relay, let's just say that it's a classic. This one isn't in particularly wonderful physical condition, and has some corrosion. I think it's an airborne variant, and some of the plating on the N sockets has corroded off. Notwithstanding that the insertion-loss is ~0.2dB at 1.3GHz, ~0.25dB at 2.3, and 0.35dB at 3.0GHz measured in the last few minutes on an in cal. HP8753ES network analyser. The return loss is >30dB across the DC - 3GHz range. These measurements have been made on the NC port. Isolation between the output ports is >60dB up to 3GHz.

The snags. The main issue is that the relay has coils designed for 115Vac operation. I don't have a convenient source of safe 115V here, and so I can't confirm the performance of the other port. I think that it should work as the DC resistance sort of makes sense, but I can't and won't guarantee it.

I have enough other relays in my 'junkbox' to last me for a long time, so, if someone thinks they can make use of they can have it, as seen, for £15 plus £5 contribution to P&P ...

Email me at <gw4dgu@...> if you are interested. First come, first served.

Vy 73

Chris
GW4DGU
--


Christopher Bartram <cbartram@...>
 

The relay has now been sold ...

73

Chris

--
Christopher Bartram MIET
Christopher Bartram RF Design
Llygad yr Haul
Carno
CAERSWS
Powys SY17 5LE

phone: +44 1686 237732
mobile: +44 7545 094490
email: cbartram@...
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Note: This message is for the named person's use only. It may contain confidential, proprietary or legally privileged information. No confidentiality or privilege is waived or lost by any mistransmission. If you receive this message in error, please immediately delete it and all copies of it from your system, destroy any hard copies of it and notify the sender. You must not, directly or indirectly, use, disclose, distribute, print, or copy any part of this message if you are not the intended recipient. Christopher Bartram RF Design reserves the right to monitor all e-mail communications through its network. Any views expressed in this message are those of the individual sender, except where the message states otherwise and the sender is authorised to state them to be the views of any such entity.


Andy G4JNT
 

On the subject of its 110VAC coil.    I don't have any AC relays of any type  to test this idea, but has anyone ever made tests on an AC relay to find what its DC pull in / hold on characteristics are?

I don't know if there are any core differences - apart from its being laminated I suspect on the bigger coils, but can they be operated from a constant voltage, or current?

If the requirements end up at reasonable values without the risk of the coil cooking, there are enough SMPSU modules around now with variable output voltage to make use of them.

'jnt


On 16 March 2016 at 18:44, Christopher Bartram cbartram@... [ukmicrowaves] <ukmicrowaves@...> wrote:
 

The relay has now been sold ...

73

Chris

--
Christopher Bartram MIET
Christopher Bartram RF Design
Llygad yr Haul
Carno
CAERSWS
Powys SY17 5LE

phone: +44 1686 237732
mobile: +44 7545 094490
email: cbartram@...
URL: www.christopherbartramrfdesign.com

Note: This message is for the named person's use only. It may contain confidential, proprietary or legally privileged information. No confidentiality or privilege is waived or lost by any mistransmission. If you receive this message in error, please immediately delete it and all copies of it from your system, destroy any hard copies of it and notify the sender. You must not, directly or indirectly, use, disclose, distribute, print, or copy any part of this message if you are not the intended recipient. Christopher Bartram RF Design reserves the right to monitor all e-mail communications through its network. Any views expressed in this message are those of the individual sender, except where the message states otherwise and the sender is authorised to state them to be the views of any such entity.



John Quarmby
 

I have successfully used a relay with a 240V AC coil with 100V DC applied in a 2m PA built 40 yrs ago that's still going well. On that basis a supply of around 50V DC might work with 110V AC coils.

73

John G3XDY


On 16/03/2016 18:51, Andy Talbot andy.g4jnt@... [ukmicrowaves] wrote:
On the subject of its 110VAC coil.    I don't have any AC relays of any type  to test this idea, but has anyone ever made tests on an AC relay to find what its DC pull in / hold on characteristics are?

I don't know if there are any core differences - apart from its being laminated I suspect on the bigger coils, but can they be operated from a constant voltage, or current?

If the requirements end up at reasonable values without the risk of the coil cooking, there are enough SMPSU modules around now with variable output voltage to make use of them.

'jnt


On 16 March 2016 at 18:44, Christopher Bartram cbartram@... [ukmicrowaves] <ukmicrowaves@...> wrote:
 

The relay has now been sold ...

73

Chris

--
Christopher Bartram MIET
Christopher Bartram RF Design
Llygad yr Haul
Carno
CAERSWS
Powys SY17 5LE

phone: +44 1686 237732
mobile: +44 7545 094490
email: cbartram@...
URL: www.christopherbartramrfdesign.com

Note: This message is for the named person's use only. It may contain confidential, proprietary or legally privileged information. No confidentiality or privilege is waived or lost by any mistransmission. If you receive this message in error, please immediately delete it and all copies of it from your system, destroy any hard copies of it and notify the sender. You must not, directly or indirectly, use, disclose, distribute, print, or copy any part of this message if you are not the intended recipient. Christopher Bartram RF Design reserves the right to monitor all e-mail communications through its network. Any views expressed in this message are those of the individual sender, except where the message states otherwise and the sender is authorised to state them to be the views of any such entity.




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Pete - GM4BYF
 

I have tested two 110V a.c. relays – did try to sell them on eBay. Memory is that they pulled in okay at 28V. I’ll see if I can find them
73
 
Pete GM4BYF
 

Sent: Wednesday, March 16, 2016 7:01 PM
Subject: Re: [ukmicrowaves] FS: Transco Y Relay
 
 

I have successfully used a relay with a 240V AC coil with 100V DC applied in a 2m PA built 40 yrs ago that's still going well. On that basis a supply of around 50V DC might work with 110V AC coils.

73

John G3XDY


On 16/03/2016 18:51, Andy Talbot andy.g4jnt@... [ukmicrowaves] wrote:
On the subject of its 110VAC coil.    I don't have any AC relays of any type  to test this idea, but has anyone ever made tests on an AC relay to find what its DC pull in / hold on characteristics are?
 
I don't know if there are any core differences - apart from its being laminated I suspect on the bigger coils, but can they be operated from a constant voltage, or current?
 
If the requirements end up at reasonable values without the risk of the coil cooking, there are enough SMPSU modules around now with variable output voltage to make use of them.
 
'jnt
 
 
On 16 March 2016 at 18:44, Christopher Bartram cbartram@... [ukmicrowaves] <ukmicrowaves@...> wrote:
 

The relay has now been sold ...

73

Chris

--
Christopher Bartram MIET
Christopher Bartram RF Design
Llygad yr Haul
Carno
CAERSWS
Powys SY17 5LE

phone: +44 1686 237732
mobile: +44 7545 094490
email: cbartram@...
URL: www.christopherbartramrfdesign.com

Note: This message is for the named person's use only. It may contain confidential, proprietary or legally privileged information. No confidentiality or privilege is waived or lost by any mistransmission. If you receive this message in error, please immediately delete it and all copies of it from your system, destroy any hard copies of it and notify the sender. You must not, directly or indirectly, use, disclose, distribute, print, or copy any part of this message if you are not the intended recipient. Christopher Bartram RF Design reserves the right to monitor all e-mail communications through its network. Any views expressed in this message are those of the individual sender, except where the message states otherwise and the sender is authorised to state them to be the views of any such entity.

 


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Peter G3SMT
 

Andy,

The rule of thumb is that an AC rated relay will operate the same when used on DC at 50% of the AC voltage.  AC relays have a shading ring fitted to help suppress any tendency to hum but have no effect when DC is used.

73

Peter
G3SMT


On 16/03/2016 18:51, Andy Talbot andy.g4jnt@... [ukmicrowaves] wrote:
 
On the subject of its 110VAC coil.    I don't have any AC relays of any type  to test this idea, but has anyone ever made tests on an AC relay to find what its DC pull in / hold on characteristics are?

I don't know if there are any core differences - apart from its being laminated I suspect on the bigger coils, but can they be operated from a constant voltage, or current?

If the requirements end up at reasonable values without the risk of the coil cooking, there are enough SMPSU modules around now with variable output voltage to make use of them.

'jnt




David Robinson
 

My 110V AC coiled Y type works fine in my 48V DC amplifier

 

Dave

G4FRE

 

 

From: ukmicrowaves@... [mailto:ukmicrowaves@...]
Sent: 16 March 2016 19:02
To: ukmicrowaves@...
Subject: Re: [ukmicrowaves] FS: Transco Y Relay

 



I have successfully used a relay with a 240V AC coil with 100V DC applied in a 2m PA built 40 yrs ago that's still going well. On that basis a supply of around 50V DC might work with 110V AC coils.

73

John G3XDY

On 16/03/2016 18:51, Andy Talbot andy.g4jnt@... [ukmicrowaves] wrote:

On the subject of its 110VAC coil.    I don't have any AC relays of any type  to test this idea, but has anyone ever made tests on an AC relay to find what its DC pull in / hold on characteristics are?

 

I don't know if there are any core differences - apart from its being laminated I suspect on the bigger coils, but can they be operated from a constant voltage, or current?

 

If the requirements end up at reasonable values without the risk of the coil cooking, there are enough SMPSU modules around now with variable output voltage to make use of them.

 

'jnt

 

 

On 16 March 2016 at 18:44, Christopher Bartram cbartram@... [ukmicrowaves] <ukmicrowaves@...> wrote:

 

The relay has now been sold ...

73

Chris

--
Christopher Bartram MIET
Christopher Bartram RF Design
Llygad yr Haul
Carno
CAERSWS
Powys SY17 5LE

phone: +44 1686 237732
mobile: +44 7545 094490
email: cbartram@...
URL: www.christopherbartramrfdesign.com

Note: This message is for the named person's use only. It may contain confidential, proprietary or legally privileged information. No confidentiality or privilege is waived or lost by any mistransmission. If you receive this message in error, please immediately delete it and all copies of it from your system, destroy any hard copies of it and notify the sender. You must not, directly or indirectly, use, disclose, distribute, print, or copy any part of this message if you are not the intended recipient. Christopher Bartram RF Design reserves the right to monitor all e-mail communications through its network. Any views expressed in this message are those of the individual sender, except where the message states otherwise and the sender is authorised to state them to be the views of any such entity.

 

 

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Paul <paul@...>
 

As the one that bought the Transco from Chris can I say many thanks to eyeryone for all the advice about operating it on DC. It is very much appreciated. With 110V AC coils I had expected to have to put it in the amplifier and move the amplifier relay to a new masthead amp. But if it will work on 50V DC then I'm happy to put the Transco at the masthead.

I gather it's a good idea to heatsink them by bolting the relay to a lump of aluminium?

I have been after a Transco Y relay for some time but used ones (who can afford a new one!) only seem to come up for sale on ebay in the USA with eye watering postage costs.

73 Paul G4DCV

On 16-Mar-16 19:42, 'Dave' g4fre@... [ukmicrowaves] wrote:
 

My 110V AC coiled Y type works fine in my 48V DC amplifier

 

Dave

G4FRE

 

 

From: ukmicrowaves@... [mailto:ukmicrowaves@...]
Sent: 16 March 2016 19:02
To: ukmicrowaves@...
Subject: Re: [ukmicrowaves] FS: Transco Y Relay

 



I have successfully used a relay with a 240V AC coil with 100V DC applied in a 2m PA built 40 yrs ago that's still going well. On that basis a supply of around 50V DC might work with 110V AC coils.

73

John G3XDY

On 16/03/2016 18:51, Andy Talbot andy.g4jnt@... [ukmicrowaves] wrote:

On the subject of its 110VAC coil.    I don't have any AC relays of any type  to test this idea, but has anyone ever made tests on an AC relay to find what its DC pull in / hold on characteristics are?

 

I don't know if there are any core differences - apart from its being laminated I suspect on the bigger coils, but can they be operated from a constant voltage, or current?

 

If the requirements end up at reasonable values without the risk of the coil cooking, there are enough SMPSU modules around now with variable output voltage to make use of them.

 

'jnt

 

 

On 16 March 2016 at 18:44, Christopher Bartram cbartram@... [ukmicrowaves] <ukmicrowaves@...> wrote:

 

The relay has now been sold ...

73

Chris

--
Christopher Bartram MIET
Christopher Bartram RF Design
Llygad yr Haul
Carno
CAERSWS
Powys SY17 5LE

phone: +44 1686 237732
mobile: +44 7545 094490
email: cbartram@...
URL: www.christopherbartramrfdesign.com

Note: This message is for the named person's use only. It may contain confidential, proprietary or legally privileged information. No confidentiality or privilege is waived or lost by any mistransmission. If you receive this message in error, please immediately delete it and all copies of it from your system, destroy any hard copies of it and notify the sender. You must not, directly or indirectly, use, disclose, distribute, print, or copy any part of this message if you are not the intended recipient. Christopher Bartram RF Design reserves the right to monitor all e-mail communications through its network. Any views expressed in this message are those of the individual sender, except where the message states otherwise and the sender is authorised to state them to be the views of any such entity.

 

 

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Alan G0XBV
 

Chris made reference to the coil resistance of the relay.  I have an Amphenol relay with a 110VAC coil.  I believe it's R is ~550 ohms.  It's not to hand just now, but I will check it later.  Thanks to Peter for that rule of thumb - I will need to know that too at some stage!
 
I don't recall which book/mag/internet article I was reading recently, Paul (it could have been the VHF DX manual), but there was a reference to relay heat sinking.  The general thread was that if the relay was energised for RX, it would be a good idea to do so. 
 
Al G0XBV
 

-----Original Message-----
From: Paul paul@... [ukmicrowaves]
To: ukmicrowaves
Sent: Wed, 16 Mar 2016 23:25
Subject: Re: [ukmicrowaves] FS: Transco Y Relay

 
As the one that bought the Transco from Chris can I say many thanks to eyeryone for all the advice about operating it on DC. It is very much appreciated. With 110V AC coils I had expected to have to put it in the amplifier and move the amplifier relay to a new masthead amp. But if it will work on 50V DC then I'm happy to put the Transco at the masthead.

I gather it's a good idea to heatsink them by bolting the relay to a lump of aluminium?

I have been after a Transco Y relay for some time but used ones (who can afford a new one!) only seem to come up for sale on ebay in the USA with eye watering postage costs.

73 Paul G4DCV

On 16-Mar-16 19:42, 'Dave' g4fre@... [ukmicrowaves] wrote:
 
My 110V AC coiled Y type works fine in my 48V DC amplifier
 
Dave
G4FRE
 
 
From: ukmicrowaves@... [mailto:ukmicrowaves@...]
Sent: 16 March 2016 19:02
To: ukmicrowaves@...
Subject: Re: [ukmicrowaves] FS: Transco Y Relay
 


I have successfully used a relay with a 240V AC coil with 100V DC applied in a 2m PA built 40 yrs ago that's still going well. On that basis a supply of around 50V DC might work with 110V AC coils.

73

John G3XDY

On 16/03/2016 18:51, Andy Talbot andy.g4jnt@... [ukmicrowaves] wrote:
On the subject of its 110VAC coil.    I don't have any AC relays of any type  to test this idea, but has anyone ever made tests on an AC relay to find what its DC pull in / hold on characteristics are?
 
I don't know if there are any core differences - apart from its being laminated I suspect on the bigger coils, but can they be operated from a constant voltage, or current?
 
If the requirements end up at reasonable values without the risk of the coil cooking, there are enough SMPSU modules around now with variable output voltage to make use of them.
 
'jnt
 
 
On 16 March 2016 at 18:44, Christopher Bartram cbartram@... [ukmicrowaves] <ukmicrowaves@...> wrote:
 
The relay has now been sold ...

73

Chris

--
Christopher Bartram MIET
Christopher Bartram RF Design
Llygad yr Haul
Carno
CAERSWS
Powys SY17 5LE

phone: +44 1686 237732
mobile: +44 7545 094490
email: cbartram@...
URL: www.christopherbartramrfdesign.com

Note: This message is for the named person's use only. It may contain confidential, proprietary or legally privileged information. No confidentiality or privilege is waived or lost by any mistransmission. If you receive this message in error, please immediately delete it and all copies of it from your system, destroy any hard copies of it and notify the sender. You must not, directly or indirectly, use, disclose, distribute, print, or copy any part of this message if you are not the intended recipient. Christopher Bartram RF Design reserves the right to monitor all e-mail communications through its network. Any views expressed in this message are those of the individual sender, except where the message states otherwise and the sender is authorised to state them to be the views of any such entity.
 
 
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Alan G0XBV
 

-----Original Message-----
From: ALANNOTTAGE@... [ukmicrowaves]
To: ukmicrowaves
Sent: Thu, 17 Mar 2016 16:47
Subject: Re: [ukmicrowaves] FS: Transco Y Relay

>Chris made reference to the coil resistance of the relay.  I have an Amphenol relay with a 110VAC coil.  I believe it's R is ~550 ohms.  It's not to hand just now, but I will check it later.  Thanks to Peter for that rule of thumb - I will need to know that >too at some stage!
 
The spec of my coil is 550 ohms and measures out nearer to 500.  In comparison, the 26V DC models are all around 200 ohms.  From a DC perspective, that would seem to bear out everyone's experiences then.  I still have no idea how they actually work with AC applied :>)
 
Al G0XBV
 
 
 
 
 
 
 


Andy G4JNT
 

I believe the purpose of the "shading ring" on AC solenoids is to continue the flux - ie effectively keep a current flowing - during the low portion of the sine.  Quite how it does it I don't know, but I'm just delving into memory of many many decades ago.  

 It would have to use non linearities in the core material to work though, as harmonics of the AC flux  would have to be present to fill in the gaps

Got me pondering now - having just also remembered shaded pole motors.   I didn't understand them then (1970's) and still don't know exactly what the shorted turn does.

'jnt

On 18 March 2016 at 12:31, ALANNOTTAGE@... [ukmicrowaves] <ukmicrowaves@...> wrote:
 

-----Original Message-----
From: ALANNOTTAGE@... [ukmicrowaves] <ukmicrowaves@...>
To: ukmicrowaves <ukmicrowaves@...>
Sent: Thu, 17 Mar 2016 16:47
Subject: Re: [ukmicrowaves] FS: Transco Y Relay

>Chris made reference to the coil resistance of the relay.  I have an Amphenol relay with a 110VAC coil.  I believe it's R is ~550 ohms.  It's not to hand just now, but I will check it later.  Thanks to Peter for that rule of thumb - I will need to know that >too at some stage!
 
The spec of my coil is 550 ohms and measures out nearer to 500.  In comparison, the 26V DC models are all around 200 ohms.  From a DC perspective, that would seem to bear out everyone's experiences then.  I still have no idea how they actually work with AC applied :>)
 
Al G0XBV
 
 
 
 
 
 
 



Peter G3SMT
 

Digging back into my memory I recall that AC relays used a laminated iron core to reduce Eddy current losses and hysteresis losses.  To avoid chatter and humming of the armature part of the pole face had a shading ring fitted. The flux created in this ring, usually copper, is phase shifted relative to the flux in the main core so preventing the main flux from periodically going through zero.
Its a long while since I had a connection with relays rather than just using them.

73

Peter
G3SMT

 

On 18/03/2016 12:37, Andy Talbot andy.g4jnt@... [ukmicrowaves] wrote:
 
I believe the purpose of the "shading ring" on AC solenoids is to continue the flux - ie effectively keep a current flowing - during the low portion of the sine.  Quite how it does it I don't know, but I'm just delving into memory of many many decades ago.  

 It would have to use non linearities in the core material to work though, as harmonics of the AC flux  would have to be present to fill in the gaps

Got me pondering now - having just also remembered shaded pole motors.   I didn't understand them then (1970's) and still don't know exactly what the shorted turn does.

'jnt

 



Alan G0XBV
 

Andy, Peter - that is fascinating stuff.  I just couldn't fathom how it wouldn't hum and chatter!
 
Many thanks!
 
Alan G0XBV 
 

-----Original Message-----
From: Peter Torry peter.torry@... [ukmicrowaves]
To: ukmicrowaves
Sent: Fri, 18 Mar 2016 14:12
Subject: Re: [ukmicrowaves] FS: Transco Y Relay

 
Digging back into my memory I recall that AC relays used a laminated iron core to reduce Eddy current losses and hysteresis losses.  To avoid chatter and humming of the armature part of the pole face had a shading ring fitted. The flux created in this ring, usually copper, is phase shifted relative to the flux in the main core so preventing the main flux from periodically going through zero.
Its a long while since I had a connection with relays rather than just using them.

73

Peter
G3SMT

 

On 18/03/2016 12:37, Andy Talbot andy.g4jnt@... [ukmicrowaves] wrote:
 
I believe the purpose of the "shading ring" on AC solenoids is to continue the flux - ie effectively keep a current flowing - during the low portion of the sine.  Quite how it does it I don't know, but I'm just delving into memory of many many decades ago.  

 It would have to use non linearities in the core material to work though, as harmonics of the AC flux  would have to be present to fill in the gaps

Got me pondering now - having just also remembered shaded pole motors.   I didn't understand them then (1970's) and still don't know exactly what the shorted turn does.

'jnt

 



John E. Beech
 

The reason AC relays work is because both polepieces are magnetized by the energizing current. The shorted turn acts like a transformer and increases the magnetizing current at the pole piece. This induced current is in antiphase too the main magnetizing current ( Lenz's Law). This ensures that the magnetic pole is of opposite polarity thus the stator and amature always attract each other irresspective of the direction of current flow. The shaded ploe motors usually have two shorted turns on each pole, one offset from the other so that the  motor always starts rotating in the forward direction.

 
de John G8SEQ

  -------Original Message-------
From: Andy Talbot andy.g4jnt@... [ukmicrowaves]
To: ukmicrowaves@...
Subject: Re: [ukmicrowaves] FS: Transco Y Relay
Sent: Mar 18 '16 12:54

 
I believe the purpose of the "shading ring" on AC solenoids is to continue the flux - ie effectively keep a current flowing - during the low portion of the sine.  Quite how it does it I don't know, but I'm just delving into memory of many many decades ago.  
 
 It would have to use non linearities in the core material to work though, as harmonics of the AC flux  would have to be present to fill in the gaps
 
Got me pondering now - having just also remembered shaded pole motors.   I didn't understand them then (1970's) and still don't know exactly what the shorted turn does.
 
'jnt

On 18 March 2016 at 12:31, ALANNOTTAGE@... [ukmicrowaves] <ukmicrowaves@...> wrote:
 

 

-----Original Message-----
From: ALANNOTTAGE@... [ukmicrowaves] <ukmicrowaves@...>
To: ukmicrowaves <ukmicrowaves@...>
Sent: Thu, 17 Mar 2016 16:47
Subject: Re: [ukmicrowaves] FS: Transco Y Relay
>Chris made reference to the coil resistance of the relay.  I have an Amphenol relay with a 110VAC coil.  I believe it's R is ~550 ohms.  It's not to hand just now, but I will check it later.  Thanks to Peter for that rule of thumb - I will need to know that >too at some stage!
 
The spec of my coil is 550 ohms and measures out nearer to 500.  In comparison, the 26V DC models are all around 200 ohms.  From a DC perspective, that would seem to bear out everyone's experiences then.  I still have no idea how they actually work with AC applied :>)
 
Al G0XBV
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 

 


Paul <paul@...>
 

Hi Al

This sent me leafing through my well-thumbed copy of the VHF/UHF DX Book. BTW I wish we had a modern version of this book. No mention of the Transco in the section about coax relays but there is a thread (started by Conrad G0CUZ/PA5Y) on Moon-Net that does indeed suggest heat sinking the Transco is desireable:

http://mailman.pe1itr.com/pipermail/moon-net/2013-June/016517.html

Useful info for anyone who needs to service or repair a Transco here:

http://kl6m.com/LNA-RELAY.pdf

73 Paul G4DCV

On 17-Mar-16 16:47, ALANNOTTAGE@... [ukmicrowaves] wrote:
 

Chris made reference to the coil resistance of the relay.  I have an Amphenol relay with a 110VAC coil.  I believe it's R is ~550 ohms.  It's not to hand just now, but I will check it later.  Thanks to Peter for that rule of thumb - I will need to know that too at some stage!
 
I don't recall which book/mag/internet article I was reading recently, Paul (it could have been the VHF DX manual), but there was a reference to relay heat sinking.  The general thread was that if the relay was energised for RX, it would be a good idea to do so. 
 
Al G0XBV
 



Paul <paul@...>
 

Hi Al

Follow up to the message I sent a few minutes ago. I also found this in the instructions for the JWM sequencer, "A word of caution related to RF relays that are always in a constant energized state. Most of these relays are not designed to be energized for long periods of time, and will require a good heatsink to dissipate the heat that can build up. Transco “Y” relays for example can be energized for several hours at a time when mounted to an aluminum plate about 12 inches square or so, by ¼ inch to 3/8 inch thick. To provide the best possible heat transfer, use transistor thermal heatsink compound when you mount the relays to the aluminum plate."

Paul G4DCV

On 17-Mar-16 16:47, ALANNOTTAGE@... [ukmicrowaves] wrote:
 

Chris made reference to the coil resistance of the relay.  I have an Amphenol relay with a 110VAC coil.  I believe it's R is ~550 ohms.  It's not to hand just now, but I will check it later.  Thanks to Peter for that rule of thumb - I will need to know that too at some stage!
 
I don't recall which book/mag/internet article I was reading recently, Paul (it could have been the VHF DX manual), but there was a reference to relay heat sinking.  The general thread was that if the relay was energised for RX, it would be a good idea to do so. 
 
Al G0XBV
 



Alan G0XBV
 

That's where I read it, Paul - well found!  I have a similar (as in y-shaped) relay (with a duff solenoid as it happens) and was looking for an internal picture of the Transco to see if it's construction was similar (the moving switch contact is disk-shaped) and maybe to gauge how worthwhile it might be to rewind it.   
 
Good to hear you were able to source what you were looking for at a respectable price and if you do mount it at the masthead, then at least the enclosure will be nice and toasty inside :) 
 
Al G0XBV
 
 

-----Original Message-----
From: Paul paul@... [ukmicrowaves]
To: ukmicrowaves
Sent: Fri, 18 Mar 2016 18:17
Subject: Re: [ukmicrowaves] FS: Transco Y Relay

 
Hi Al

This sent me leafing through my well-thumbed copy of the VHF/UHF DX Book. BTW I wish we had a modern version of this book. No mention of the Transco in the section about coax relays but there is a thread (started by Conrad G0CUZ/PA5Y) on Moon-Net that does indeed suggest heat sinking the Transco is desireable:

http://mailman.pe1itr.com/pipermail/moon-net/2013-June/016517.html

Useful info for anyone who needs to service or repair a Transco here:

http://kl6m.com/LNA-RELAY.pdf

73 Paul G4DCV

On 17-Mar-16 16:47, ALANNOTTAGE@... [ukmicrowaves] wrote:
 
Chris made reference to the coil resistance of the relay.  I have an Amphenol relay with a 110VAC coil.  I believe it's R is ~550 ohms.  It's not to hand just now, but I will check it later.  Thanks to Peter for that rule of thumb - I will need to know that too at some stage!
 
I don't recall which book/mag/internet article I was reading recently, Paul (it could have been the VHF DX manual), but there was a reference to relay heat sinking.  The general thread was that if the relay was energised for RX, it would be a good idea to do so. 
 
Al G0XBV
 



Alan G0XBV
 

There could be a case for evaluating that in advance (and maybe with any model?), i.e. powering it up on the bench and checking the temp. rise.  It's possible that's how mine failed in it's previous life wherever.  It's on a cad-plated steel plate, but not anywhere near as big as below. 
Al G0XBV
 
 

-----Original Message-----
From: Paul paul@... [ukmicrowaves]
To: ukmicrowaves
Sent: Fri, 18 Mar 2016 18:21
Subject: Re: [ukmicrowaves] FS: Transco Y Relay

 
Hi Al

Follow up to the message I sent a few minutes ago. I also found this in the instructions for the JWM sequencer, "A word of caution related to RF relays that are always in a constant energized state. Most of these relays are not designed to be energized for long periods of time, and will require a good heatsink to dissipate the heat that can build up. Transco “Y” relays for example can be energized for several hours at a time when mounted to an aluminum plate about 12 inches square or so, by ¼ inch to 3/8 inch thick. To provide the best possible heat transfer, use transistor thermal heatsink compound when you mount the relays to the aluminum plate."

Paul G4DCV

On 17-Mar-16 16:47, ALANNOTTAGE@... [ukmicrowaves] wrote:
 
Chris made reference to the coil resistance of the relay.  I have an Amphenol relay with a 110VAC coil.  I believe it's R is ~550 ohms.  It's not to hand just now, but I will check it later.  Thanks to Peter for that rule of thumb - I will need to know that too at some stage!
 
I don't recall which book/mag/internet article I was reading recently, Paul (it could have been the VHF DX manual), but there was a reference to relay heat sinking.  The general thread was that if the relay was energised for RX, it would be a good idea to do so. 
 
Al G0XBV
 



Andy G4JNT
 

It maybe worth considering a customised bit of drive circuitry;  one that pulls in at a high voltage than drops to a lower holding value - or a constant current supply.    Both manageable with 'Simple-Switcher' SMPSU  devices.

'jnt


On 19 March 2016 at 12:34, ALANNOTTAGE@... [ukmicrowaves] <ukmicrowaves@...> wrote:
 

There could be a case for evaluating that in advance (and maybe with any model?), i.e. powering it up on the bench and checking the temp. rise.  It's possible that's how mine failed in it's previous life wherever.  It's on a cad-plated steel plate, but not anywhere near as big as below. 
Al G0XBV
 
 
-----Original Message-----
From: Paul paul@... [ukmicrowaves] <ukmicrowaves@...>
To: ukmicrowaves <ukmicrowaves@...>
Sent: Fri, 18 Mar 2016 18:21
Subject: Re: [ukmicrowaves] FS: Transco Y Relay

 
Hi Al

Follow up to the message I sent a few minutes ago. I also found this in the instructions for the JWM sequencer, "A word of caution related to RF relays that are always in a constant energized state. Most of these relays are not designed to be energized for long periods of time, and will require a good heatsink to dissipate the heat that can build up. Transco “Y” relays for example can be energized for several hours at a time when mounted to an aluminum plate about 12 inches square or so, by ¼ inch to 3/8 inch thick. To provide the best possible heat transfer, use transistor thermal heatsink compound when you mount the relays to the aluminum plate."

Paul G4DCV

On 17-Mar-16 16:47, ALANNOTTAGE@... [ukmicrowaves] wrote:
 
Chris made reference to the coil resistance of the relay.  I have an Amphenol relay with a 110VAC coil.  I believe it's R is ~550 ohms.  It's not to hand just now, but I will check it later.  Thanks to Peter for that rule of thumb - I will need to know that too at some stage!
 
I don't recall which book/mag/internet article I was reading recently, Paul (it could have been the VHF DX manual), but there was a reference to relay heat sinking.  The general thread was that if the relay was energised for RX, it would be a good idea to do so. 
 
Al G0XBV
 




Alan G0XBV
 

I was thinking along those lines too, Andy...but without the device knowledge!  Mike 'LYP had some good ideas on here last year about devices with which to control heated masthead enclosures (to banish condensation), so I imagine the two objectives could be combined, though maybe not the best of engineering practice :>) 
 
Al G0XBV
 
 

-----Original Message-----
From: Andy Talbot andy.g4jnt@... [ukmicrowaves]
To: ukmicrowaves <ukmicrowaves@...>
Sent: Sat, 19 Mar 2016 12:37
Subject: Re: [ukmicrowaves] FS: Transco Y Relay

 
It maybe worth considering a customised bit of drive circuitry;  one that pulls in at a high voltage than drops to a lower holding value - or a constant current supply.    Both manageable with 'Simple-Switcher' SMPSU  devices.

'jnt


On 19 March 2016 at 12:34, ALANNOTTAGE@... [ukmicrowaves] <ukmicrowaves@...> wrote:
 
There could be a case for evaluating that in advance (and maybe with any model?), i.e. powering it up on the bench and checking the temp. rise.  It's possible that's how mine failed in it's previous life wherever.  It's on a cad-plated steel plate, but not anywhere near as big as below. 
Al G0XBV
 
 
-----Original Message-----
From: Paul paul@... [ukmicrowaves] <ukmicrowaves@...>
To: ukmicrowaves <ukmicrowaves@...>
Sent: Fri, 18 Mar 2016 18:21
Subject: Re: [ukmicrowaves] FS: Transco Y Relay

 
Hi Al

Follow up to the message I sent a few minutes ago. I also found this in the instructions for the JWM sequencer, "A word of caution related to RF relays that are always in a constant energized state. Most of these relays are not designed to be energized for long periods of time, and will require a good heatsink to dissipate the heat that can build up. Transco “Y” relays for example can be energized for several hours at a time when mounted to an aluminum plate about 12 inches square or so, by ¼ inch to 3/8 inch thick. To provide the best possible heat transfer, use transistor thermal heatsink compound when you mount the relays to the aluminum plate."

Paul G4DCV

On 17-Mar-16 16:47, ALANNOTTAGE@... [ukmicrowaves] wrote:
 
Chris made reference to the coil resistance of the relay.  I have an Amphenol relay with a 110VAC coil.  I believe it's R is ~550 ohms.  It's not to hand just now, but I will check it later.  Thanks to Peter for that rule of thumb - I will need to know that too at some stage!
 
I don't recall which book/mag/internet article I was reading recently, Paul (it could have been the VHF DX manual), but there was a reference to relay heat sinking.  The general thread was that if the relay was energised for RX, it would be a good idea to do so. 
 
Al G0XBV