Date   

Re: ALC Overrun

Andy G4JNT
 

Use a 50 ohm resistor as a load and connect a diode detector across it.  A 1N914 etc will suffice  .   Transmit from your rig into that and use the scope to monitor the diode voltage.   That should show any ALC overshoot.



On Thu, 8 Apr 2021 at 09:48, Algenon <alg_edwards@...> wrote:
Hi Microwave Group 

I’m new to the forum and looking for some advice on what I believe is called ALC Overrun. I am looking at purchasing an SG Labs 1296 transverter to get started on 23cms. All the advice is to use an IF radio with a max output power of 5W. I would like to use my Icom-7100 with the power turned down to 5W as the IF radio but I understand that some radios can momentarily output more power than set  thus damaging the transverter. Does the group have experience of this combo and/or is there a way for me to detect if the radio does output momentarily in excess of the set power. I have basic test equipment: dummy load, power meter, 50Mhz scope which I suspect will not detect any blip. 


ALC Overrun

Algenon M0JIO
 

Hi Microwave Group 

I’m new to the forum and looking for some advice on what I believe is called ALC Overrun. I am looking at purchasing an SG Labs 1296 transverter to get started on 23cms. All the advice is to use an IF radio with a max output power of 5W. I would like to use my Icom-7100 with the power turned down to 5W as the IF radio but I understand that some radios can momentarily output more power than set  thus damaging the transverter. Does the group have experience of this combo and/or is there a way for me to detect if the radio does output momentarily in excess of the set power. I have basic test equipment: dummy load, power meter, 50Mhz scope which I suspect will not detect any blip. 


Re: New British 122 GHz distance record

Barry Chambers
 

Chris, Roger

well done!

73

Barry, G8AGN



On 08/04/2021 09:19, Chris G0FDZ wrote:

Hi folks

Yesterday (7th April ) at 1030 UTC a new British 122 GHz distance record was made over 35.925 kms by Roger G8CUB/P and Chris G0FDZ/P, between Danbury in Essex and Minster on the Isle of Sheppey.

More info and photos will be found in the forthcoming edition of Scatterpoint.

Regards

Chris G0FDZ


Virus-free. www.avg.com
-- 
73
Barry, G8AGN


New British 122 GHz distance record

Chris G0FDZ
 

Hi folks

Yesterday (7th April ) at 1030 UTC a new British 122 GHz distance record was made over 35.925 kms by Roger G8CUB/P and Chris G0FDZ/P, between Danbury in Essex and Minster on the Isle of Sheppey.

More info and photos will be found in the forthcoming edition of Scatterpoint.

Regards

Chris G0FDZ


Virus-free. www.avg.com


Re: low ESR caps on 4351

militaryoperator
 

Don't know Dave, I'm not well versed in the likes of phase noise and pll's etc. 
I just hear what the clever chaps say and try and give it a go. 

Don't even know what I'll use the boards for but thought it best to make the mods just in case, hi. 

Ben



Subject: Re: [UKMicrowaves] low ESR caps on 4351

A useful outcome, Ben.
Surprised to see that much power in the skirts.

Is this `as well as` or `instead of``?

Dave, G1OGY


On Wed, 7 Apr 2021 at 11:55, militaryoperator via groups.io <Military1944=aol.com@groups.io> wrote:
Following on from recent posting about fitting LSR caps across the regulator filter caps on 4351 boards, I fitted two 1000uf across the two regulator o/ps. Seems to have helped I think?
Ben

Before                                                                                and after.
cap.jpg
  
_._,_._,_


Re: low ESR caps on 4351

Dave (G1OGY)
 

A useful outcome, Ben.
Surprised to see that much power in the skirts.

Is this `as well as` or `instead of``?

Dave, G1OGY


On Wed, 7 Apr 2021 at 11:55, militaryoperator via groups.io <Military1944=aol.com@groups.io> wrote:
Following on from recent posting about fitting LSR caps across the regulator filter caps on 4351 boards, I fitted two 1000uf across the two regulator o/ps. Seems to have helped I think?
Ben

Before                                                                                and after.
  


Re: Retuning a 23cm duplexer, any hints please?

Alan Beard
 

Hi all,

I gave up on the BandPass-BandReject and went with 25mm x 25mm dividers
as in the attached pixture. This reduced the pass bandwidth to 10MHz centered on
1274 MHz and 1294 MHz with 50db or so attenuation of the other frequency.
The input RL is -16db or better.

Measured by the SAA-V2.

Alan VK2ZIW

On Wed, 7 Apr 2021 07:28:52 +1000, Alan Beard via groups.io wrote
> Hi all,
>
>

> Thomas Eddison 'tinkered' until the breakthrough...
>
>

> The figure of 8 loop did the trick.
>
>

>
>

> Where are the 'tinkerers' out there????
>
> I've achieved a super steep slope on the high side of a pass, now
> to see if I can get another super steep slope on the lower frequency 
> side of the high pass. 
>
>

> Come on guys, where's your imagination?
>
>

> Alan VK2ZIW
>
>

> On Tue, 6 Apr 2021 07:44:42 +1000, Alan Beard via groups.io wrote
> > Hi all,
> > Here are my mods to this 1800 MHz duplexer so far:
> >
> > > www.unixservice.com.au/hamradio/repeaters/duplexers/23CMpix/
> > IMG_3809c.JPG
> > Tuning is now much easier with the M3 screws further out, out from the 4mm ID tube.
> >
> > My next question is:
> >


---------------------------------------------------
Alan VK2ZIW
Before the Big Bang, God, Sela.
OpenWebMail 2.53, nothing in the cloud.


Re: Heatshrink

Colin Ranson
 

John,

 

Same here, I have a two setting heat gun as well – and I concur !

 

 

Glad you sorted it.

 

Regards   Colin.

 

Sent from Mail for Windows 10

 

From: John Lemay
Sent: 07 April 2021 16:48
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Heatshrink

 

Hello all

Thanks for your helpful comments about heatshrink, on and off list.

Turns out, after some experimentation today, that it is pilot error -
although I'd prefer to blame my tools; My two setting heat gun has turned
itself into a single setting - the low one of course - and it is man enough
to shrink the material but not enough to get the glue flowing nicely.

Time for a bit of retail therapy !

John G4ZTR

-----Original Message-----
From: UKMicrowaves@groups.io [mailto:UKMicrowaves@groups.io] On Behalf Of
Conrad, PA5Y
Sent: 07 April 2021 09:57
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Heatshrink

Hi Frank I use Raychem heatshrink with overlapped 3M self-amalgamating tape
and finally Denso tape. I also have bright shiny connectors after a good
number of years. Don't forget to wind the tape so that when it tries to
unravel it tightens the connector. I am sure I'm not the only one who has
seen that if you do it wrong it can unscrew the connectors. Not seen this
happen for years but I have heard from other installers that it is quite
common.

Denso tape is really the best thing for the job.

73

Conrad PA5Y

-----Original Message-----
From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> On Behalf Of frank
evans via groups.io
Sent: 07 April 2021 00:51
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Heatshrink

John

As someone who spent his working life installing professional communications
aerials can I recommend you to Denso tape, It's the absolute best. A light
Hessian tape seriously impregnated with a heavy wax. Inexpensive, and
available in a range of widths from your local plumber's merchants or on
line

Frank GW8AWM

-----Original Message-----
From: UKMicrowaves@groups.io [mailto:UKMicrowaves@groups.io] On Behalf Of
John Lemay
Sent: 06 April 2021 19:38
To: UKMicrowaves@groups.io
Subject: [UKMicrowaves] Heatshrink


I've spent part of today tidying up cables and repositioning masthead boxes
on 23, 13 and 9cms. While doing this it became clear that I could make a
better job of it by changing an angle N type to a straight one.

When I stripped back the glued heatshrink I discovered that it had not
adhered to the cable (LDF4-50) at all, and it wasn't much better on the plug
body. It wasn't an eBay cheapo buy, but it wasn't from Andrews/Commscope
either.

Any recommendations for decent quality sticky heatshrink please ?

Thanks

John G4ZTR























 


Re: Heatshrink

John Lemay
 

Hello all

Thanks for your helpful comments about heatshrink, on and off list.

Turns out, after some experimentation today, that it is pilot error -
although I'd prefer to blame my tools; My two setting heat gun has turned
itself into a single setting - the low one of course - and it is man enough
to shrink the material but not enough to get the glue flowing nicely.

Time for a bit of retail therapy !

John G4ZTR

-----Original Message-----
From: UKMicrowaves@groups.io [mailto:UKMicrowaves@groups.io] On Behalf Of
Conrad, PA5Y
Sent: 07 April 2021 09:57
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Heatshrink

Hi Frank I use Raychem heatshrink with overlapped 3M self-amalgamating tape
and finally Denso tape. I also have bright shiny connectors after a good
number of years. Don't forget to wind the tape so that when it tries to
unravel it tightens the connector. I am sure I'm not the only one who has
seen that if you do it wrong it can unscrew the connectors. Not seen this
happen for years but I have heard from other installers that it is quite
common.

Denso tape is really the best thing for the job.

73

Conrad PA5Y

-----Original Message-----
From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> On Behalf Of frank
evans via groups.io
Sent: 07 April 2021 00:51
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Heatshrink

John

As someone who spent his working life installing professional communications
aerials can I recommend you to Denso tape, It's the absolute best. A light
Hessian tape seriously impregnated with a heavy wax. Inexpensive, and
available in a range of widths from your local plumber's merchants or on
line

Frank GW8AWM

-----Original Message-----
From: UKMicrowaves@groups.io [mailto:UKMicrowaves@groups.io] On Behalf Of
John Lemay
Sent: 06 April 2021 19:38
To: UKMicrowaves@groups.io
Subject: [UKMicrowaves] Heatshrink


I've spent part of today tidying up cables and repositioning masthead boxes
on 23, 13 and 9cms. While doing this it became clear that I could make a
better job of it by changing an angle N type to a straight one.

When I stripped back the glued heatshrink I discovered that it had not
adhered to the cable (LDF4-50) at all, and it wasn't much better on the plug
body. It wasn't an eBay cheapo buy, but it wasn't from Andrews/Commscope
either.

Any recommendations for decent quality sticky heatshrink please ?

Thanks

John G4ZTR


low ESR caps on 4351

militaryoperator
 

Following on from recent posting about fitting LSR caps across the regulator filter caps on 4351 boards, I fitted two 1000uf across the two regulator o/ps. Seems to have helped I think?
Ben

Before                                                                                and after.
cap.jpg
  


Re: Heatshrink

Conrad, PA5Y
 

Hi Frank I use Raychem heatshrink with overlapped 3M self-amalgamating tape and finally Denso tape. I also have bright shiny connectors after a good number of years. Don't forget to wind the tape so that when it tries to unravel it tightens the connector. I am sure I'm not the only one who has seen that if you do it wrong it can unscrew the connectors. Not seen this happen for years but I have heard from other installers that it is quite common.

Denso tape is really the best thing for the job.

73

Conrad PA5Y

-----Original Message-----
From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> On Behalf Of frank evans via groups.io
Sent: 07 April 2021 00:51
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Heatshrink

John

As someone who spent his working life installing professional communications aerials can I recommend you to Denso tape, It's the absolute best. A light Hessian tape seriously impregnated with a heavy wax. Inexpensive, and available in a range of widths from your local plumber's merchants or on line

Frank GW8AWM

-----Original Message-----
From: UKMicrowaves@groups.io [mailto:UKMicrowaves@groups.io] On Behalf Of John Lemay
Sent: 06 April 2021 19:38
To: UKMicrowaves@groups.io
Subject: [UKMicrowaves] Heatshrink


I've spent part of today tidying up cables and repositioning masthead boxes on 23, 13 and 9cms. While doing this it became clear that I could make a better job of it by changing an angle N type to a straight one.

When I stripped back the glued heatshrink I discovered that it had not adhered to the cable (LDF4-50) at all, and it wasn't much better on the plug body. It wasn't an eBay cheapo buy, but it wasn't from Andrews/Commscope either.

Any recommendations for decent quality sticky heatshrink please ?

Thanks

John G4ZTR


Re: Heatshrink

Conrad, PA5Y
 

Hello John, the Raychem stuff is perfect.

https://awbroadcast.com/produkt/raychem-mwt-m-25-8-schrumpfschlauch-1000mm/

You must be able to find a UK source I would have thought.

73

Conrad PA5Y

-----Original Message-----
From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> On Behalf Of John Lemay via groups.io
Sent: 06 April 2021 20:38
To: UKMicrowaves@groups.io
Subject: [UKMicrowaves] Heatshrink

I've spent part of today tidying up cables and repositioning masthead boxes on 23, 13 and 9cms. While doing this it became clear that I could make a better job of it by changing an angle N type to a straight one.

When I stripped back the glued heatshrink I discovered that it had not adhered to the cable (LDF4-50) at all, and it wasn't much better on the plug body. It wasn't an eBay cheapo buy, but it wasn't from Andrews/Commscope either.

Any recommendations for decent quality sticky heatshrink please ?

Thanks

John G4ZTR


Re: Heatshrink

frank evans
 

John

As someone who spent his working life installing professional
communications aerials can I recommend you to Denso tape, It's the
absolute best. A light Hessian tape seriously impregnated with a heavy
wax. Inexpensive, and available in a range of widths from your local
plumber's merchants or on line

Frank GW8AWM

-----Original Message-----
From: UKMicrowaves@groups.io [mailto:UKMicrowaves@groups.io] On Behalf
Of John Lemay
Sent: 06 April 2021 19:38
To: UKMicrowaves@groups.io
Subject: [UKMicrowaves] Heatshrink


I've spent part of today tidying up cables and repositioning masthead
boxes on 23, 13 and 9cms. While doing this it became clear that I could
make a better job of it by changing an angle N type to a straight one.

When I stripped back the glued heatshrink I discovered that it had not
adhered to the cable (LDF4-50) at all, and it wasn't much better on the
plug body. It wasn't an eBay cheapo buy, but it wasn't from
Andrews/Commscope either.

Any recommendations for decent quality sticky heatshrink please ?

Thanks

John G4ZTR


Re: Heatshrink

Paul G8AQA
 

Hi John,

eBay item number: 282357541289

 works ok for me. Plenty of glue oozes out. Various sizes available.

Paul G8AQA

On 06/04/2021 19:37, John Lemay wrote:
I've spent part of today tidying up cables and repositioning masthead boxes
on 23, 13 and 9cms. While doing this it became clear that I could make a
better job of it by changing an angle N type to a straight one.

When I stripped back the glued heatshrink I discovered that it had not
adhered to the cable (LDF4-50) at all, and it wasn't much better on the plug
body. It wasn't an eBay cheapo buy, but it wasn't from Andrews/Commscope
either.

Any recommendations for decent quality sticky heatshrink please ?

Thanks

John G4ZTR





--
This email has been checked for viruses by AVG.
https://www.avg.com


Re: Heatshrink

Alan Melia
 

Hi John I have a fair length of adhesive heatshrink in stock. It came from Rapid a couple of years back and is big enough to fit over an N-type connection. I can send you a bit to try if it would help.

I tend to use adhesive tape and self-amalgamating tape as was demo'd to me by some professional riggers when the company I was with ran a few common base PMR (repeater) stations on TV sites.

Either way the glue adhesion to the jacket is vital to stop moisture creeping into the connection.

Alan
G3NYK

----- Original Message -----
From: "John Lemay" <john@carltonhouse.eclipse.co.uk>
To: <UKMicrowaves@groups.io>
Sent: Tuesday, April 06, 2021 7:37 PM
Subject: [UKMicrowaves] Heatshrink


I've spent part of today tidying up cables and repositioning masthead boxes
on 23, 13 and 9cms. While doing this it became clear that I could make a
better job of it by changing an angle N type to a straight one.

When I stripped back the glued heatshrink I discovered that it had not
adhered to the cable (LDF4-50) at all, and it wasn't much better on the plug
body. It wasn't an eBay cheapo buy, but it wasn't from Andrews/Commscope
either.

Any recommendations for decent quality sticky heatshrink please ?

Thanks

John G4ZTR






Re: Retuning a 23cm duplexer, any hints please?

Alan Beard
 

Hi all,

Thomas Eddison 'tinkered' until the breakthrough...

The figure of 8 loop did the trick.


Where are the 'tinkerers' out there????

I've achieved a super steep slope on the high side of a pass, now
to see if I can get another super steep slope on the lower frequency 
side of the high pass. 

Come on guys, where's your imagination?

Alan VK2ZIW

On Tue, 6 Apr 2021 07:44:42 +1000, Alan Beard via groups.io wrote
> Hi all,
> Here are my mods to this 1800 MHz duplexer so far:
>
> > www.unixservice.com.au/hamradio/repeaters/duplexers/23CMpix/
> IMG_3809c.JPG
> Tuning is now much easier with the M3 screws further out, out from the 4mm ID tube.
>
> My next question is:
>
> Can the inter-digital filter be made BandPass and BandReject?
>
> (as we do for 2m repeaters) (photos, drawings please)
>
> Our 20 MHz split for 23cm repeaters is pretty tight.
>
> I see nothing on the web.
>
> Alan VK2ZIW
>
>

>
>

> On Sun, 4 Apr 2021 22:05:14 +0000 (UTC), KENT BRITAIN wrote
> > Interestingly the 3rd harmonic is not exactly 3X the 430 MHz frequency, but close.
> > Often easier to do the first tuning at the 430 MHz frequency,m then fine tune at the 23 cm frequency.
> >
> > Quite often we see the 450 MHz filters from commercial mobile radios surplus.  Most of those tune 23 cm as well.   Good luck with your project,  Kent WA5VJB/G8EMY
> >
> > On Sunday, April 4, 2021, 4:43:42 PM CDT, Alan Beard via groups.io <beardal@...> wrote:
> >
> > Thanks Kent,
> >

> > We have a "parrot" 23cm repeater over in the Wollongong area and changing it to Full duplex will require
> > cavity filters. I acquired this one, at a good price a few years ago. Perhaps spares never used.
> > Using 70cm cavities in 3rd overtone is a great idea. 
> >

>
> ---------------------------------------------------
> Alan VK2ZIW
> Before the Big Bang, God, Sela.
> OpenWebMail 2.53, nothing in the cloud.
>
>

---------------------------------------------------
Alan VK2ZIW
Before the Big Bang, God, Sela.
OpenWebMail 2.53, nothing in the cloud.


Re: Heatshrink

Lou Blasco
 

Hi John,

Rather than heat shrink, I use amalgamating Butyl tape which forms an excellent weatherproof barrier that is not sticky to the touch. Even after more than 10 years out in the weather, silver RF connectors are still bright and shiny without a hint of tarnish. To remove, just cut away with a sharp blade. It might be an alternate solution to your non sticky heat shrink.

image.png

Regards

Lou
VK3ALB


On Wed, Apr 7, 2021 at 5:03 AM ian hope (2E0IJH) <ian@...> wrote:
John I use the 3M stuff I also use for work splicing cables, decent amount of glue seems to come out ends and never had a issue with it
 
 
Ian
M5IJH
 
 
Sent: Tuesday, April 06, 2021 at 7:37 PM
From: "John Lemay" <john@...>
To: UKMicrowaves@groups.io
Subject: [UKMicrowaves] Heatshrink
I've spent part of today tidying up cables and repositioning masthead boxes
on 23, 13 and 9cms. While doing this it became clear that I could make a
better job of it by changing an angle N type to a straight one.

When I stripped back the glued heatshrink I discovered that it had not
adhered to the cable (LDF4-50) at all, and it wasn't much better on the plug
body. It wasn't an eBay cheapo buy, but it wasn't from Andrews/Commscope
either.

Any recommendations for decent quality sticky heatshrink please ?

Thanks

John G4ZTR






 


Re: Heatshrink

ian hope (2E0IJH)
 

John I use the 3M stuff I also use for work splicing cables, decent amount of glue seems to come out ends and never had a issue with it
 
https://www.3m.co.uk/3M/en_GB/electrical-construction-maintenance-uk/solutions/heat-shrink-technology/
 
Ian
M5IJH

 
 
Sent: Tuesday, April 06, 2021 at 7:37 PM
From: "John Lemay" <john@...>
To: UKMicrowaves@groups.io
Subject: [UKMicrowaves] Heatshrink
I've spent part of today tidying up cables and repositioning masthead boxes
on 23, 13 and 9cms. While doing this it became clear that I could make a
better job of it by changing an angle N type to a straight one.

When I stripped back the glued heatshrink I discovered that it had not
adhered to the cable (LDF4-50) at all, and it wasn't much better on the plug
body. It wasn't an eBay cheapo buy, but it wasn't from Andrews/Commscope
either.

Any recommendations for decent quality sticky heatshrink please ?

Thanks

John G4ZTR






 


Re: Drive level

militaryoperator
 

Depends where you put the resistor in the chain, whether you make the inbuilt attenator greater or smaller.
 


Yes, guess its a matter of adding a resistor or actually, as in this case, reducing a resistor. 
All in the way its phrased obviously. English, a great language. 

BN


Heatshrink

John Lemay
 

I've spent part of today tidying up cables and repositioning masthead boxes
on 23, 13 and 9cms. While doing this it became clear that I could make a
better job of it by changing an angle N type to a straight one.

When I stripped back the glued heatshrink I discovered that it had not
adhered to the cable (LDF4-50) at all, and it wasn't much better on the plug
body. It wasn't an eBay cheapo buy, but it wasn't from Andrews/Commscope
either.

Any recommendations for decent quality sticky heatshrink please ?

Thanks

John G4ZTR

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