Date   

Re: Pump up Masts

Mike Willis
 

After some googling it looks very much like it is one of these with the compressor and valve accessories

http://www.nrentech.com/pneumatic-telescopic-mast/9m-SecurityCCTV-PneumaticTelescopicMast

--
Mike G0MJW


Re: Wave guide dummy load.

John E. Beech
 

Probably more than enough; the more carbon the higher the conductivity & the less lossy it is. I'm guessing the pukka
foam works well because the foam structure has longer, narrow conducting parts which go in all directions which will
have cancelling electric & magnetic fields - a bit like wire wool at HF. And probably has high dielectric losses as well. ( Its
dielectric constant is fairly high at 2.5 - higher than polythene but lower than polymethyl methacrylate (Perspex).

de John G8SEQ

-------Original Message-------
From: Neil Douglas via groups.io <neil.douglas=ntlworld.com@groups.io>
To: UKMicrowaves@groups.io <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] Wave guide dummy load.
Sent: Mar 04 '21 11:57

All,

RS sell this material

THERMAL INTERFACE SHEET, GRAPHITE, 10W/M·K, 150 X 150MM 0.16MM,
SELF-ADHESIVE

£13.31 FOR 150 X 150 MM

Would this be enough carbon?

73 NeilD G4SHJ

FROM: UKMicrowaves@groups.io <UKMicrowaves@groups.io> ON BEHALF OF
KENT BRITAIN
SENT: 04 March 2021 02:03
TO: ukmicrowaves@groups.io; UKMicrowaves@groups.io
SUBJECT: Re: [UKMicrowaves] Wave guide dummy load.

Only, Only if there is enough Carbon to make the epoxy electrically
conductive.

The particles have to be touching. A little Carbon does nothing. Kent

On Wednesday, March 3, 2021, 07:22:13 PM CST, Gordon REASON via
groups.io <gordonj.reason=virgin.net@groups.io> wrote:

would'nt some carbon powder , mixed into one part of an epoxy , such
as araldite , have a good absorbtion >>>>> just thinking !
> On 03 March 2021 at 19:18 "John E. Beech" <john@g8seq.com> wrote:
>
>
> Tnx John,
> I eventually found it on page 8.20 of the 1969 edition. No mention
of it in the index under micro- or wave-
> though.
>
> de John G8SEQ
>
> > -------Original Message-------
> > From: John Fell <john.g0api@gmail.com>
> > To: UKMicrowaves@groups.io <UKMicrowaves@groups.io>
> > Subject: Re: [UKMicrowaves] microwave absorbent adhesive polymer?
> > Sent: Mar 03 '21 10:57
> >
> > RSGB VHF Manual - Microwave section .Wood in guide dummy load .
> >
> > John
> > G0API
> >
> > On Wed, 3 Mar 2021 at 10:11, John E. Beech <john@g8seq.com>
wrote:
> >
> > > Don't laugh, but has anyone tried a thin strip of balsa wood or
> > > plywood for the absorber? ( Perhaps covered in
> > > graphite pencil lead?) I once made an effective waveguide dummy
> > > load for 10 GHz out of wood - a specially shaped
> > > wedge. I don't know where the design came from but I got it
from
> > > G8MWR (SK).
> > >
> > > de John G8SEQ
> > >
> > >> -------Original Message-------
> > >> From: Neil Smith G4DBN <neil@g4dbn.uk>
> > >> To: BVA-transverters-uk@groups.io
> > > <BVA-transverters-uk@groups.io>, UKMicrowaves@groups.io
> > > <UKMicrowaves@groups.io>
> > >> Subject: [UKMicrowaves] microwave absorbent adhesive polymer?
> > >> Sent: Mar 02 '21 23:27
> > >>
> > >> Are there any secret sources of microwave absorbant material
> > > which will
> > >> work from 2.5 to 10 GHz with good reflection loss and bulk
loss,
> > > around
> > >> 1mm thick and self-adhesive?
> > >>
> > >> For the F6BVA 3cm to UHF transverters, we need a bit about 150
x
> > > 50 mm.
> > >>
> > >> I see RF Microwave has some at around £330 for a 600 mm
square
> > > sheet of
> > >> silicone 1mm carbonyl/iron, which makes 48 pieces at around
> > > £8.50 per
> > >> piece including VAT etc. The price from Mouser etc for similar
> > > stuff
> > >> works out about the same. Is that the right sort of price or
is
> > > there
> > >> some low cost magic stuff of which I am unaware? The gap above
> > > the PCB
> > >> is only 7mm, and some of the components are a few mm tall, so
> > > 1/16" or
> > >> about 1.5 mm is the max I can fit in.
> > >>
> > >> Neil G4DBN
> > >>
> > >>
> > >>
> > >>
> > >>
> > >>
> >
> >
>
>
>
>
>


Re: ICNIRP

Dave
 

Thanks Neil,
I had a look at the RSGB calculator and see what you mean regarding the 6 minutes and the duty cycle in there.
73
Dave G4GLT.

On 4 Mar 2021, at 09:01, Neil Smith G4DBN <neil@g4dbn.uk> wrote:

of


Re: microwave absorbent adhesive polymer?

Andy G4JNT
 

Have you tried just taping over with magic Tape (*) ?
It really does work well

(*)  Other thin plastic self adhesive tapes are available.



On Thu, 4 Mar 2021 at 13:31, Gordon REASON via groups.io <gordonj.reason=virgin.net@groups.io> wrote:

RTV 3140 was our favourite adhesive .............

On 04 March 2021 at 09:32 "SAM JEWELL via groups.io" <jewell=btinternet.com@groups.io> wrote:

I would like to echo that comment about finding suitable adhesive to use with the polyurethane/silicon absorber materials. I was given a few sheets of 'plain' absorber of the sort I use with my VLNA preamps. I have tried all sorts of adhesives, but none of them adhere properly and several of them caused the absorber sheet to curl up.
I went back to the self adhesive type, expensive as it is.

73 de Sam, G4DDK



 

On 4 Mar 2021, at 08:18, Dave G8KHU <david@...> wrote:

Neil
Before you order check with Mouser that their material has the pressure sensitive adhesisve tape option - the Mouser description just says mounting is "adhesive". Does that mean it's got the adhesive film or that you need adhesive to glue it in place? The Digikey version does at least says that the adhesive is non-conductive single sided so I'm assuming that this is the factory fitted adhesive sheet . The base number just referes to the material and the laird site lists the psa as an option - https://www.laird.com/products/microwave-absorbers/microwave-absorbing-elastomers-and-films/eccosorb-mcs/21109145
The non-adhesive stuff is a pig for amateur use as nothing seems to stick it reliably, carpet tape falls off and superglue / rtv fail rapidly. The proper adhesive is a two part mix that's fiendishly expensive, comes in a one litre can which has very limited shelf life and has enough skull and crossbones warning symbols to sink a pirate ship. I had to use it once and swore never, ever, again.
HTH Dave G8KHU


 


 


Re: microwave absorbent adhesive polymer?

Gordon REASON <gordonj.reason@...>
 

RTV 3140 was our favourite adhesive .............

On 04 March 2021 at 09:32 "SAM JEWELL via groups.io" <jewell@...> wrote:

I would like to echo that comment about finding suitable adhesive to use with the polyurethane/silicon absorber materials. I was given a few sheets of 'plain' absorber of the sort I use with my VLNA preamps. I have tried all sorts of adhesives, but none of them adhere properly and several of them caused the absorber sheet to curl up.
I went back to the self adhesive type, expensive as it is.

73 de Sam, G4DDK



 

On 4 Mar 2021, at 08:18, Dave G8KHU <david@...> wrote:

Neil
Before you order check with Mouser that their material has the pressure sensitive adhesisve tape option - the Mouser description just says mounting is "adhesive". Does that mean it's got the adhesive film or that you need adhesive to glue it in place? The Digikey version does at least says that the adhesive is non-conductive single sided so I'm assuming that this is the factory fitted adhesive sheet . The base number just referes to the material and the laird site lists the psa as an option - https://www.laird.com/products/microwave-absorbers/microwave-absorbing-elastomers-and-films/eccosorb-mcs/21109145
The non-adhesive stuff is a pig for amateur use as nothing seems to stick it reliably, carpet tape falls off and superglue / rtv fail rapidly. The proper adhesive is a two part mix that's fiendishly expensive, comes in a one litre can which has very limited shelf life and has enough skull and crossbones warning symbols to sink a pirate ship. I had to use it once and swore never, ever, again.
HTH Dave G8KHU


 


 


Re: Wave guide dummy load.

KENT BRITAIN
 

I have made and even published how to make loads using that IC Carbon foam.

Some of the foam is 'Static Dissipative' and does not work well as a microwave absorber.

Get out your Ohm Meter and poke the foam with the probes about 5-10 mm apart.   If you read a few hundred Ohms it will work well.  If it reads thousands of Ohms, it will not.   Then form the foam into a wedge shape and put it in the waveguide.   Kent WA5VJB/G8EMY

On Thursday, March 4, 2021, 04:48:44 AM CST, Wilko <wkb@...> wrote:


And the old style anti-static carbon-filled foam for IC's, would that work? Something that has crossed my mind but forgot to ask for a while now

Wilko
PA1WBU






Re: microwave absorbent adhesive polymer?

SAM JEWELL
 

My experience of fridge magnet 'stuff' is not that good. I know others have reported positive results. When compared to the 'right stuff', in my various preamps, it's like chalk and cheese!
Sam, G4DDK

On 4 Mar 2021, at 10:51, John E. Beech <john@g8seq.com> wrote:

I forgot we were talking about silicone foam. Contact adhesive won't work very well either. I have some silicone glue
made by DMC which would probably stick it BUT reading the warnings on the label, I think it contains acetic acid which is
not a good idea around electronics, so if you are thinking of using silicone sealer as glue it should be the sort that
DOESEN'T smell of vinegar.

I haven't studied the detail of this project but doesn't this absorber go inside the tin plate box lid? So wouldn't the fridge
stuff be a good option?

de John G8SEQ

-------Original Message-------
From: john <john@g8seq.com>
To: UKMicrowaves@groups.io <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] microwave absorbent adhesive polymer?
Sent: Mar 04 '21 10:17

I would have thought contact adhesive such as Evostick, Bostik or Thixofix would be a good option. Snag is you only
get
one chance to stick it in the right place otherwise it is rip it off & start again.

de John G8SEQ

-------Original Message-------
From: Dave G8KHU <david@fielding-electronics.co.uk>
To: UKMicrowaves@groups.io <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] microwave absorbent adhesive polymer?
Sent: Mar 04 '21 08:18

Neil
Before you order check with Mouser that their material has the
pressure sensitive adhesisve tape option - the Mouser description just
says mounting is "adhesive". Does that mean it's got the adhesive film
or that you need adhesive to glue it in place? The Digikey version
does at least says that the adhesive is non-conductive single sided so
I'm assuming that this is the factory fitted adhesive sheet . The base
number just referes to the material and the laird site lists the psa
as an option -
https://www.laird.com/products/microwave-absorbers/microwave-absorbing-elastomers-and-films/eccosorb-
mcs/21109145
The non-adhesive stuff is a pig for amateur use as nothing seems to
stick it reliably, carpet tape falls off and superglue / rtv fail
rapidly. The proper adhesive is a two part mix that's fiendishly
expensive, comes in a one litre can which has very limited shelf life
and has enough skull and crossbones warning symbols to sink a pirate
ship. I had to use it once and swore never, ever, again.
HTH Dave G8KHU




Re: 23cm warm cable

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. 


Re: Wave guide dummy load.

Neil Douglas
 

All,

 

RS sell this material

 

Thermal Interface Sheet, Graphite, 10W/m·K, 150 x 150mm 0.16mm, Self-Adhesive

£13.31 for 150 x 150 mm

Would this be enough carbon?

73 NeilD G4SHJ

 

From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> On Behalf Of KENT BRITAIN
Sent: 04 March 2021 02:03
To: ukmicrowaves@groups.io; UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Wave guide dummy load.

 

Only, Only if there is enough Carbon to make the epoxy electrically conductive.

The particles have to be touching.       A little Carbon does nothing.    Kent

 

On Wednesday, March 3, 2021, 07:22:13 PM CST, Gordon REASON via groups.io <gordonj.reason@...> wrote:

 

 

would'nt some carbon powder , mixed into one part of an epoxy , such as araldite , have a good absorbtion >>>>>  just thinking !
> On 03 March 2021 at 19:18 "John E. Beech" <john@...> wrote:
>
>
> Tnx John,
>                I eventually found it on page 8.20 of the 1969 edition. No mention of it in the index under micro- or wave-
> though.
>
> de John G8SEQ
>
> >  -------Original Message-------
> >  From: John Fell <john.g0api@...>
> >  To: UKMicrowaves@groups.io <UKMicrowaves@groups.io>
> >  Subject: Re: [UKMicrowaves] microwave absorbent adhesive polymer?
> >  Sent: Mar 03 '21 10:57
> >
> >  RSGB VHF Manual - Microwave section .Wood in guide dummy load .
> >
> >  John
> >  G0API
> >
> >  On Wed, 3 Mar 2021 at 10:11, John E. Beech <john@...> wrote:
> >
> >  > Don't laugh, but has anyone tried a thin strip of balsa wood or
> >  > plywood for the absorber? ( Perhaps covered in
> >  > graphite pencil lead?) I once made an effective waveguide dummy
> >  > load for 10 GHz out of wood - a specially shaped
> >  > wedge. I don't know where the design came from but I got it from
> >  > G8MWR (SK).
> >  >
> >  > de John G8SEQ
> >  >
> >  >> -------Original Message-------
> >  >> From: Neil Smith G4DBN <neil@...>
> >  >> To: BVA-transverters-uk@groups.io
> >  > <BVA-transverters-uk@groups.io>, UKMicrowaves@groups.io
> >  > <UKMicrowaves@groups.io>
> >  >> Subject: [UKMicrowaves] microwave absorbent adhesive polymer?
> >  >> Sent: Mar 02 '21 23:27
> >  >>
> >  >> Are there any secret sources of microwave absorbant material
> >  > which will
> >  >> work from 2.5 to 10 GHz with good reflection loss and bulk loss,
> >  > around
> >  >> 1mm thick and self-adhesive?
> >  >>
> >  >> For the F6BVA 3cm to UHF transverters, we need a bit about 150 x
> >  > 50 mm.
> >  >>
> >  >> I see RF Microwave has some at around £330 for a 600 mm square
> >  > sheet of
> >  >> silicone 1mm carbonyl/iron, which makes 48 pieces at around
> >  > £8.50 per
> >  >> piece including VAT etc. The price from Mouser etc for similar
> >  > stuff
> >  >> works out about the same. Is that the right sort of price or is
> >  > there
> >  >> some low cost magic stuff of which I am unaware? The gap above
> >  > the PCB
> >  >> is only 7mm, and some of the components are a few mm tall, so
> >  > 1/16" or
> >  >> about 1.5 mm is the max I can fit in.
> >  >>
> >  >> Neil G4DBN
> >  >>
> >  >>
> >  >>
> >  >>
> >  >>
> >  >>
> >
> >
>
>
>
>
>





Re: 23cm warm cable

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. 


Re: ICNIRP

Brian Howie GM4DIJ
 

In message <3706.1614811907121833967@groups.io>, Graham G3VKV via groups.io <g3vkv=btinternet.com@groups.io> writes
I have used this one for a long while, if it works in VK land using
ICNIRP data then should be OK here
VK3UM downloads (vk5dj.com)
EMRcalc
Graham G3VKV
I've been using that one but I get "invalid floating point error" on W10 64 bit. It's OK on 32bit. My worst band seems to be 70cm.

Brian
--
Brian Howie


Re: microwave absorbent adhesive polymer?

SAM JEWELL
 

I've ordered some Puraflex 40 for delivery tomorrow.  I will try it on some of the various absorber sheets I have. They are marked as to type, so 
If it works it would save me buying sheets of the more expensive stuff.
Also, happy to let Neil have some absorber sheet to evaluate. I don't have enough for everyone, but it may point a cheaper way forward. If it sticks!

Sam, G4DDK




On 4 Mar 2021, at 10:43, Stuart M1GSM via groups.io <stu_watson@...> wrote:

Anyone tried polyurethane adhesive?
i.e. Puraflex, Sikaflex? it sticks to everything, wear gloves :)


Re: microwave absorbent adhesive polymer?

Colin Ranson
 

Stuart, Hi,

 

In my days of selling Sikaflex it was horribly expensive for what it was – structural adhesive/sealer. Some insurance companies would insist upon it – ‘Freds in the Sheds’ would use UPOL Tigerseal at a third of the price.    The cost of a tube Sikaflex now (off fleabay) would almost meet that of the puka self adhesive absorber.... unless you had another job for it.

 

Regards,    Colin de G8LBS.

 

Sent from Mail for Windows 10

 

From: Stuart M1GSM via groups.io
Sent: 04 March 2021 10:43
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] microwave absorbent adhesive polymer?

 

Anyone tried polyurethane adhesive?
i.e. Puraflex, Sikaflex? it sticks to everything, wear gloves :)

 


Re: microwave absorbent adhesive polymer?

John E. Beech
 

I forgot we were talking about silicone foam. Contact adhesive won't work very well either. I have some silicone glue
made by DMC which would probably stick it BUT reading the warnings on the label, I think it contains acetic acid which is
not a good idea around electronics, so if you are thinking of using silicone sealer as glue it should be the sort that
DOESEN'T smell of vinegar.

I haven't studied the detail of this project but doesn't this absorber go inside the tin plate box lid? So wouldn't the fridge
stuff be a good option?

de John G8SEQ

-------Original Message-------
From: john <john@g8seq.com>
To: UKMicrowaves@groups.io <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] microwave absorbent adhesive polymer?
Sent: Mar 04 '21 10:17

I would have thought contact adhesive such as Evostick, Bostik or Thixofix would be a good option. Snag is you only
get
one chance to stick it in the right place otherwise it is rip it off & start again.

de John G8SEQ

>  -------Original Message-------
>  From: Dave G8KHU <david@fielding-electronics.co.uk>
>  To: UKMicrowaves@groups.io <UKMicrowaves@groups.io>
>  Subject: Re: [UKMicrowaves] microwave absorbent adhesive polymer?
>  Sent: Mar 04 '21 08:18
>  
>  Neil
>  Before you order check with Mouser that their material has the
>  pressure sensitive adhesisve tape option - the Mouser description just
>  says mounting is "adhesive". Does that mean it's got the adhesive film
>  or that you need adhesive to glue it in place? The Digikey version
>  does at least says that the adhesive is non-conductive single sided so
>  I'm assuming that this is the factory fitted adhesive sheet . The base
>  number just referes to the material and the laird site lists the psa
>  as an option -
>  https://www.laird.com/products/microwave-absorbers/microwave-absorbing-elastomers-and-films/eccosorb-
mcs/21109145
>  The non-adhesive stuff is a pig for amateur use as nothing seems to
>  stick it reliably, carpet tape falls off and superglue / rtv fail
>  rapidly. The proper adhesive is a two part mix that's fiendishly
>  expensive, comes in a one litre can which has very limited shelf life
>  and has enough skull and crossbones warning symbols to sink a pirate
>  ship. I had to use it once and swore never, ever, again.
>  HTH Dave G8KHU
>  


Re: Wave guide dummy load.

Wilko
 

And the old style anti-static carbon-filled foam for IC's, would that work? Something that has crossed my mind but forgot to ask for a while now

Wilko
PA1WBU


Re: microwave absorbent adhesive polymer?

Stuart M1GSM
 

Anyone tried polyurethane adhesive?
i.e. Puraflex, Sikaflex? it sticks to everything, wear gloves :)


Re: Wave guide dummy load.

John E. Beech
 

There is an attenuator for 10 GHz in the said book (below) which consists of a piece of card scribble all over with soft
graphite pencil to make a thin (poorly ie lossy) conductive layer - basically a spresd out carbon film resistor.

Mixing carbon with epoxy resins does strange things. I once bought a pocket chess set for my son with a missing black
pawn. I cast one in epoxy resin using carbon as a filler & colourant. It never set hard and remained rubbery. I suspect a
lot of the cross links in the thermoset resin were mopped up by the carbon & became dead ends ie not linked to anything
else.

de John G8SEQ

-------Original Message-------
From: KENT BRITAIN <WA5VJB@FLASH.NET>
To: ukmicrowaves@groups.io <ukmicrowaves@groups.io>, UKMicrowaves@groups.io <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] Wave guide dummy load.
Sent: Mar 04 '21 02:02

Only, Only if there is enough Carbon to make the epoxy electrically
conductive.
The particles have to be touching. A little Carbon does nothing. Kent

On Wednesday, March 3, 2021, 07:22:13 PM CST, Gordon REASON via
groups.io <gordonj.reason=virgin.net@groups.io> wrote:

would'nt some carbon powder , mixed into one part of an epoxy , such
as araldite , have a good absorbtion >>>>> just thinking !
> On 03 March 2021 at 19:18 "John E. Beech" <john@g8seq.com> wrote:
>
>
> Tnx John,
> I eventually found it on page 8.20 of the 1969 edition. No mention
of it in the index under micro- or wave-
> though.
>
> de John G8SEQ
>
> > -------Original Message-------
> > From: John Fell <john.g0api@gmail.com>
> > To: UKMicrowaves@groups.io <UKMicrowaves@groups.io>
> > Subject: Re: [UKMicrowaves] microwave absorbent adhesive polymer?
> > Sent: Mar 03 '21 10:57
> >
> > RSGB VHF Manual - Microwave section .Wood in guide dummy load .
> >
> > John
> > G0API
> >
> > On Wed, 3 Mar 2021 at 10:11, John E. Beech <john@g8seq.com>
wrote:
> >
> > > Don't laugh, but has anyone tried a thin strip of balsa wood or
> > > plywood for the absorber? ( Perhaps covered in
> > > graphite pencil lead?) I once made an effective waveguide dummy
> > > load for 10 GHz out of wood - a specially shaped
> > > wedge. I don't know where the design came from but I got it
from
> > > G8MWR (SK).
> > >
> > > de John G8SEQ
> > >
> > >> -------Original Message-------
> > >> From: Neil Smith G4DBN <neil@g4dbn.uk>
> > >> To: BVA-transverters-uk@groups.io
> > > <BVA-transverters-uk@groups.io>, UKMicrowaves@groups.io
> > > <UKMicrowaves@groups.io>
> > >> Subject: [UKMicrowaves] microwave absorbent adhesive polymer?
> > >> Sent: Mar 02 '21 23:27
> > >>
> > >> Are there any secret sources of microwave absorbant material
> > > which will
> > >> work from 2.5 to 10 GHz with good reflection loss and bulk
loss,
> > > around
> > >> 1mm thick and self-adhesive?
> > >>
> > >> For the F6BVA 3cm to UHF transverters, we need a bit about 150
x
> > > 50 mm.
> > >>
> > >> I see RF Microwave has some at around £330 for a 600 mm
square
> > > sheet of
> > >> silicone 1mm carbonyl/iron, which makes 48 pieces at around
> > > £8.50 per
> > >> piece including VAT etc. The price from Mouser etc for similar
> > > stuff
> > >> works out about the same. Is that the right sort of price or
is
> > > there
> > >> some low cost magic stuff of which I am unaware? The gap above
> > > the PCB
> > >> is only 7mm, and some of the components are a few mm tall, so
> > > 1/16" or
> > >> about 1.5 mm is the max I can fit in.
> > >>
> > >> Neil G4DBN
> > >>
> > >>
> > >>
> > >>
> > >>
> > >>
> >
> >
>
>
>
>
>


Re: microwave absorbent adhesive polymer?

Andy G4JNT
 

Trouble is, some of then are silicone based - and few adhesives stick to silicone.   (Or PTFE, for that matter)
I never tried silicone bath sealant - may be worth a test.



On Thu, 4 Mar 2021 at 10:18, John E. Beech <john@...> wrote:
I would have thought contact adhesive such as Evostick, Bostik or Thixofix would be a good option. Snag is you only get
one chance to stick it in the right place otherwise it is rip it off & start again.

de John G8SEQ

>  -------Original Message-------
>  From: Dave G8KHU <david@...>
>  To: UKMicrowaves@groups.io <UKMicrowaves@groups.io>
>  Subject: Re: [UKMicrowaves] microwave absorbent adhesive polymer?
>  Sent: Mar 04 '21 08:18

>  Neil
>  Before you order check with Mouser that their material has the
>  pressure sensitive adhesisve tape option - the Mouser description just
>  says mounting is "adhesive". Does that mean it's got the adhesive film
>  or that you need adhesive to glue it in place? The Digikey version
>  does at least says that the adhesive is non-conductive single sided so
>  I'm assuming that this is the factory fitted adhesive sheet . The base
>  number just referes to the material and the laird site lists the psa
>  as an option -
https://www.laird.com/products/microwave-absorbers/microwave-absorbing-elastomers-and-films/eccosorb-
mcs/21109145

>  The non-adhesive stuff is a pig for amateur use as nothing seems to
>  stick it reliably, carpet tape falls off and superglue / rtv fail
>  rapidly. The proper adhesive is a two part mix that's fiendishly
>  expensive, comes in a one litre can which has very limited shelf life
>  and has enough skull and crossbones warning symbols to sink a pirate
>  ship. I had to use it once and swore never, ever, again.
>  HTH Dave G8KHU







Re: ICNIRP

davidm0ghz
 

Average exposure over 30mins for the whole body - ref Table 5 of ICNIRP Guidelines March 2020.  The 6mins is for parts of the body.

73 David M0GHZ


Re: microwave absorbent adhesive polymer?

John E. Beech
 

I would have thought contact adhesive such as Evostick, Bostik or Thixofix would be a good option. Snag is you only get
one chance to stick it in the right place otherwise it is rip it off & start again.

de John G8SEQ

-------Original Message-------
From: Dave G8KHU <david@fielding-electronics.co.uk>
To: UKMicrowaves@groups.io <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] microwave absorbent adhesive polymer?
Sent: Mar 04 '21 08:18

Neil
Before you order check with Mouser that their material has the
pressure sensitive adhesisve tape option - the Mouser description just
says mounting is "adhesive". Does that mean it's got the adhesive film
or that you need adhesive to glue it in place? The Digikey version
does at least says that the adhesive is non-conductive single sided so
I'm assuming that this is the factory fitted adhesive sheet . The base
number just referes to the material and the laird site lists the psa
as an option -
https://www.laird.com/products/microwave-absorbers/microwave-absorbing-elastomers-and-films/eccosorb-
mcs/21109145
The non-adhesive stuff is a pig for amateur use as nothing seems to
stick it reliably, carpet tape falls off and superglue / rtv fail
rapidly. The proper adhesive is a two part mix that's fiendishly
expensive, comes in a one litre can which has very limited shelf life
and has enough skull and crossbones warning symbols to sink a pirate
ship. I had to use it once and swore never, ever, again.
HTH Dave G8KHU

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