Date   
Re: Maximum Power using FR4 board ?

Neil Smith G4DBN
 

Hi Simon, if you need some metalbashing doing to make a stripline combiner, I would be happy to help with the fiddly bits. Drop me an email to neil@...

Seems sad to have to compromise your design for the sake of getting a bit of machining done.

Neil G4DBN

Simon wrote:
This is  a simple question what is the maximum power anyone would risk using a 1/4 length strip line on FR4 on 23cms ? 
 
Why because my metal working tools and skills are close zero and I am thinking of building a Wilkinson divider. 

Re: Feeding an LNB with an external reference through the coax

Colin G4EML
 

Are you sure you have completely disconnected the socket you are using for the reference input from its original connections?
If you have left the DC feed inductor connected it will look like a very low impedance to ground when fed with 25MHz which could be reducing the signal level too much.
 
 
 
 
 

From: Arved M0KDS
Sent: Sunday, June 16, 2019 5:16 PM
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Feeding an LNB with an external reference through the coax
 
Hi keith,

thanks for getting back to me.

Unfortunately I've only got 1nF and 100nF caps here, so that's a bit unfortunate.

I tried adding a 56Ohm Resistor, it seems to have made it worse when fed directly at the pad with a coaxial cable.
Feeding the reference through the coax is still not working.

73 Arved M0KDS

Re: Feeding an LNB with an external reference through the coax

Colin G4EML
 

Are you sure you have completely disconnected the socket you are using for the reference input from its original connections?
If you have left the DC feed inductor connected it will look like a very low impedance to ground when fed with 25MHz which could be reducing the signal level too much.
 
 
 
 
 

From: Arved M0KDS
Sent: Sunday, June 16, 2019 5:16 PM
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Feeding an LNB with an external reference through the coax
 
Hi keith,

thanks for getting back to me.

Unfortunately I've only got 1nF and 100nF caps here, so that's a bit unfortunate.

I tried adding a 56Ohm Resistor, it seems to have made it worse when fed directly at the pad with a coaxial cable.
Feeding the reference through the coax is still not working.

73 Arved M0KDS

Re: Maximum Power using FR4 board ?

KENT BRITAIN
 

Are you looking for a 2 way or a 4 way?    I just picked up a dozen commercial 4 way power dividers.  Kent



On Sunday, June 16, 2019, 1:29:31 PM CDT, Neil Smith G4DBN <neil@...> wrote:


Hi Simon, if you need some metalbashing doing to make a stripline combiner, I would be happy to help with the fiddly bits. Drop me an email to neil@...

Seems sad to have to compromise your design for the sake of getting a bit of machining done.

Neil G4DBN

Simon wrote:
This is  a simple question what is the maximum power anyone would risk using a 1/4 length strip line on FR4 on 23cms ? 
 
Why because my metal working tools and skills are close zero and I am thinking of building a Wilkinson divider. 

Re: Feeding an LNB with an external reference through the coax

Richard <richard@...>
 

What waveform are you putting thru the coax ?
If you are starting off with a square wave , on a short length used on direct connection the input will be quiet happy ,but
if you are shoving a square wave up 15 ~ 20mtrs of coax you can get some very strange effects. Best to put the 25MHz through a LPF and get rid of harmonic content
and put a nice clean sine wave up the coax, At least then you know what getting to the PLL as a reference,
HTH


On Sun, 2019-06-16 at 07:06 -0700, Arved M0KDS wrote:
Good afternoon all,

I've been working on locking my LNB with a GPSDO reference signal for QO-100 use.
The LNB I'be got is a GI-202 with two separate outputs. My plan is to modify one side to accept a reference signal while the other one will stay stock for DATV use. 
Unfortunately, I can't seem to get the LNB to lock with the reference signal being fed through the coax. I'm using a 100nF capacitor connected to the more sensitive pad (found by testing) and then running a wire from the cap to the f-connector pin. For some reason that isn't working at all. 

If I connect a piece of coax to the sensitive pad and feeding it directly to the LNB without going through the IF coax it works perfectly, no issues whatsoever. 
Does anyone have an idea why feeding through the IF coax isn't working at all?

I did use a probe to see if the reference signal is actually coming through to the LNB - it comes in loud and clear, with a few dBs of loss which comes from the RG-6 coaxial cable. 
Another thing I noticed is that the pads on the modified side have a voltage of about 0.2V on them, whilst the pads on the other unmodified side have about 2V on them. 

If anyone has an idea what might be happening here that would be great. I attached some pictures of my work to this message/email. 

Many thanks and 73,

Arved M0KDS

-- 
 Best wishes /73 
 Richard Bown
 
 Email : richard@...

 HTTP  :  http://www.g8jvm.com
 
 ######################################################################

 Ham Call: G8JVM . QRV: 50-432 MHz + Microwave 
 Maidenhead QRA: IO82SP38, LAT. 52 39.720' N LONG. 2 28.171 W
 QRV 6mtrs 200W, 4mtrs 150W, 2mtrs 300W, 70cms 200W, 
Microwave 1296MHz 140W, 2320MHz 100W & 10368MHz 5W
 OS: Linux Mint 19.1 x86_64 Tessa, on a Dell Inspiron N5030 laptop
 ######################################################################

Activity List for the UK Microwave Group mm-wave contests - Sunday 23rd June 0900-1700z

John Quarmby
 

Next Sunday sees the UKuG's major mm-wave event of the year, covering all bands from 24GHz to 248GHz. I know that maps were being carefully consulted at the RAL round table yesterday to plot possible paths, so I hope there will be some good distances worked on all bands.

The rules are here:

https://www.microwavers.org/files/2019-mwrules.pdf

As usual I will assemble an activity list and post it here, Please send details of your plans by close of play on Friday this week and I will consolidate them and send out the list on Saturday. Please note that the exchange for these events asks for 8 character locator information to be exchanged and logged.

73

John G3XDY

UKuG Contest Manager

Re: Maximum Power using FR4 board ?

simonchettle
 

Hi  All
 
Many thanks for the comments and advice.
 
Kent – It’s a 2 way splitter (Shame) but thanks for the offer.
 
Chris – Yes I vaguely remember building an air strip line back in the 70s and had all the maths – long since lost after several moves.  However that is the route I will probably take.
 
73s
 
Simon
 
 
 

From: KENT BRITAIN
Sent: Sunday, June 16, 2019 8:00 PM
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Maximum Power using FR4 board ?
 
Are you looking for a 2 way or a 4 way?    I just picked up a dozen commercial 4 way power dividers.  Kent
 
 
 
On Sunday, June 16, 2019, 1:29:31 PM CDT, Neil Smith G4DBN <neil@...> wrote:
 
 
Hi Simon, if you need some metalbashing doing to make a stripline combiner, I would be happy to help with the fiddly bits. Drop me an email to neil@...
 
Seems sad to have to compromise your design for the sake of getting a bit of machining done.
 
Neil G4DBN
 
Simon wrote:
This is  a simple question what is the maximum power anyone would risk using a 1/4 length strip line on FR4 on 23cms ?
 
Why because my metal working tools and skills are close zero and I am thinking of building a Wilkinson divider.

Re: Feeding an LNB with an external reference through the coax

G4WIM KT6UK
 

I’ve looked into locking a lnb for narrow band transponder use and while it worked I found that it degraded the the wide band datv MER which is my main interest.
So for narrow band use I now employ sdr console which takes care of the drift and associated frequency offsets.  I use a Lime sdr on tx and it works very nicely with no need to phase lock the lnb.  However I do use a rtl dongle with a 0.2ppm reference.

When I wad phase locking the lnb I made a triplexer at each end of the coax with one port for DC, another for 25MHz sinewave and another for the 750MHz if signals.

73 Tim

RAL Seller with the Florida RF loads

Paul M0EYT
 

Hi all,

I cannot remember who it was at RAL that had the dummy load modules, please could they ping me pjm@... if they are reading this.

Great round table btw!

regards,

Paul M0EYT

digi modes 3cms

Richard <richard@...>
 

Whats the most used digital mode on 3cms now ?
--
Best wishes /73
Richard Bown

Email : richard@...

HTTP : http://www.g8jvm.com

######################################################################

Ham Call: G8JVM . QRV: 50-432 MHz + Microwave
Maidenhead QRA: IO82SP38, LAT. 52 39.720' N LONG. 2 28.171 W
QRV 6mtrs 200W, 4mtrs 150W, 2mtrs 300W, 70cms 200W,
Microwave 1296MHz 140W, 2320MHz 100W & 10368MHz 5W
OS: Linux Mint 19.1 x86_64 Tessa, on a Dell Inspiron N5030 laptop
######################################################################

Re: digi modes 3cms

Neil Smith G4DBN
 

From where I am sitting, I'd say JT4G for tropo and JT9F-fast for aircraft scatter.  Pretty much like 23/13cm in fact. Or for REAL silliness, FT8 over NBFM via rainscatter (yes, REALLY!).

EME is a different matter, and I'm still building, but I see about half and half QRA64 and JT4G on the discussions and spots. Once I get the new dish in place, I'll be able to tell you what I see.  Just had a notification that my damn great 130kg 8 inch galvanised ground post for the 3m solid dish is in progress at the local fabrication shop.

However, and this is a big "however", I'd suggest that there isn't really a "most used" mode for terrestrial on 10GHz, as everyone is experimenting with *every* mode. Obviously for contacts of any distance, where the scintillation is more than a few Hz, narrow modes are not going to work too well, so WSPR and FT4/8 and the very narrow JT9 slow modes are not going to be reliable.

A fair proportion of the stations are only active /P, and there are good practical reasons why those ops are not able to run MGM, but it does feel like we are missing a trick when we could go to much lower S/N ratios with MGM.

There is also a bit of a constraint on tx/rx changeover time for those of us using waveguide relays.  5-second over JT9F-fast is just a bit too much, and 10-second overs mean you can't complete an aircraft-scatter QSO in a single reflection, whereas with CW or SSB, it is usually possible. I'm hoping my new Sivers WR90 relay will be able to manage 5s overs.

If anyone fancies trying digimodes on 3cm, even over unpromising paths or from what you might believe are terrible home locations, I am usually around on Monday and Friday evenings and occasional Wednesdays and happy to make ad-hoc skeds at almost any other time if there is decent tropo or rainscatter.

Neil G4DBN

On 17/06/2019 17:55, Richard wrote:
Whats the most used digital mode on 3cms now ?

Re: digi modes 3cms

SAM JEWELL
 

I have taken my 3cm transverter off my mast for now. Locking problem. However, I am seriously thinking about mounting a PLL controlled (just the internal 25MHz crystal) LNB near the top of my mast, for monitoring purposes. The LNBs are reasonably weatherproof. The complication of mounting the body of the LNB in a box, with the radome poking out, may be a stage too far!

As the horn on the LNB is designed to illuminate high F/D offset dishes with low sidelobes to keep adjacent satellite signals down, it may have an acceptable (but low) gain, sufficient for this purpose. I can run the IF, with dc, over the single RG58 cable normally used for the 106.5MZhz reference. It will be interesting to see what can be heard (and seen) on the RSP2 or Lime mini.
I wonder if the software could be modified to track a single carrier, from a very low power generator on the ground, as in the QO100 beacon? Maybe generate a pseudo PSK signal so that the software doesn’t need modifying?
 
Sam

On Monday, June 17, 2019, 6:44 pm, Neil Smith G4DBN <neil@...> wrote:

From where I am sitting, I'd say JT4G for tropo and JT9F-fast for
aircraft scatter.  Pretty much like 23/13cm in fact. Or for REAL
silliness, FT8 over NBFM via rainscatter (yes, REALLY!).

EME is a different matter, and I'm still building, but I see about half
and half QRA64 and JT4G on the discussions and spots. Once I get the new
dish in place, I'll be able to tell you what I see.  Just had a
notification that my damn great 130kg 8 inch galvanised ground post for
the 3m solid dish is in progress at the local fabrication shop.

However, and this is a big "however", I'd suggest that there isn't
really a "most used" mode for terrestrial on 10GHz, as everyone is
experimenting with *every* mode. Obviously for contacts of any distance,
where the scintillation is more than a few Hz, narrow modes are not
going to work too well, so WSPR and FT4/8 and the very narrow JT9 slow
modes are not going to be reliable.

A fair proportion of the stations are only active /P, and there are good
practical reasons why those ops are not able to run MGM, but it does
feel like we are missing a trick when we could go to much lower S/N
ratios with MGM.

There is also a bit of a constraint on tx/rx changeover time for those
of us using waveguide relays.  5-second over JT9F-fast is just a bit too
much, and 10-second overs mean you can't complete an aircraft-scatter
QSO in a single reflection, whereas with CW or SSB, it is usually
possible. I'm hoping my new Sivers WR90 relay will be able to manage 5s
overs.

If anyone fancies trying digimodes on 3cm, even over unpromising paths
or from what you might believe are terrible home locations, I am usually
around on Monday and Friday evenings and occasional Wednesdays and happy
to make ad-hoc skeds at almost any other time if there is decent tropo
or rainscatter.

Neil G4DBN

On 17/06/2019 17:55, Richard wrote:
> Whats the most used digital mode on 3cms now ?


Re: digi modes 3cms

Richard <richard@...>
 

Thanks Neil

On Mon, 2019-06-17 at 18:43 +0100, Neil Smith G4DBN wrote:
From where I am sitting, I'd say JT4G for tropo and JT9F-fast for
aircraft scatter. Pretty much like 23/13cm in fact. Or for REAL
silliness, FT8 over NBFM via rainscatter (yes, REALLY!).

EME is a different matter, and I'm still building, but I see about
half
and half QRA64 and JT4G on the discussions and spots. Once I get the
new
dish in place, I'll be able to tell you what I see. Just had a
notification that my damn great 130kg 8 inch galvanised ground post
for
the 3m solid dish is in progress at the local fabrication shop.

However, and this is a big "however", I'd suggest that there isn't
really a "most used" mode for terrestrial on 10GHz, as everyone is
experimenting with *every* mode. Obviously for contacts of any
distance,
where the scintillation is more than a few Hz, narrow modes are not
going to work too well, so WSPR and FT4/8 and the very narrow JT9
slow
modes are not going to be reliable.

A fair proportion of the stations are only active /P, and there are
good
practical reasons why those ops are not able to run MGM, but it does
feel like we are missing a trick when we could go to much lower S/N
ratios with MGM.

There is also a bit of a constraint on tx/rx changeover time for
those
of us using waveguide relays. 5-second over JT9F-fast is just a bit
too
much, and 10-second overs mean you can't complete an aircraft-
scatter
QSO in a single reflection, whereas with CW or SSB, it is usually
possible. I'm hoping my new Sivers WR90 relay will be able to manage
5s
overs.

If anyone fancies trying digimodes on 3cm, even over unpromising
paths
or from what you might believe are terrible home locations, I am
usually
around on Monday and Friday evenings and occasional Wednesdays and
happy
to make ad-hoc skeds at almost any other time if there is decent
tropo
or rainscatter.

Neil G4DBN

On 17/06/2019 17:55, Richard wrote:
Whats the most used digital mode on 3cms now ?

--
Best wishes /73
Richard Bown

Email : richard@...

HTTP : http://www.g8jvm.com

######################################################################

Ham Call: G8JVM . QRV: 50-432 MHz + Microwave
Maidenhead QRA: IO82SP38, LAT. 52 39.720' N LONG. 2 28.171 W
QRV 6mtrs 200W, 4mtrs 150W, 2mtrs 300W, 70cms 200W,
Microwave 1296MHz 140W, 2320MHz 100W & 10368MHz 5W
OS: Linux Mint 19.1 x86_64 Tessa, on a Dell Inspiron N5030 laptop
######################################################################

Re: Maximum Power using FR4 board ?

Neil Douglas
 

Simon,

 

Try this

 

https://www.qsl.net/g0ruz/dj9bv_23cms.htm

 

its fairly simple metal bashing.

 

also

 

W6PQL has 500W ones on Rogers substrate.

 

 

&3

 

NeilD G4SHJ

 

 

 

From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> On Behalf Of simonchettle
Sent: 17 June 2019 16:22
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Maximum Power using FR4 board ?

 

Hi  All

 

Many thanks for the comments and advice.

 

Kent – It’s a 2 way splitter (Shame) but thanks for the offer.

 

Chris – Yes I vaguely remember building an air strip line back in the 70s and had all the maths – long since lost after several moves.  However that is the route I will probably take.

 

73s

 

Simon

 

 

 

From: KENT BRITAIN

Sent: Sunday, June 16, 2019 8:00 PM

Subject: Re: [UKMicrowaves] Maximum Power using FR4 board ?

 

Are you looking for a 2 way or a 4 way?    I just picked up a dozen commercial 4 way power dividers.  Kent

 

 

 

On Sunday, June 16, 2019, 1:29:31 PM CDT, Neil Smith G4DBN <neil@...> wrote:

 

 

Hi Simon, if you need some metalbashing doing to make a stripline combiner, I would be happy to help with the fiddly bits. Drop me an email to neil@...

 

Seems sad to have to compromise your design for the sake of getting a bit of machining done.

 

Neil G4DBN

 

Simon wrote:

This is  a simple question what is the maximum power anyone would risk using a 1/4 length strip line on FR4 on 23cms ?

 

Why because my metal working tools and skills are close zero and I am thinking of building a Wilkinson divider.

Re: digi modes 3cms

John Worsnop
 

JT4G

73 John

On Mon, 17 Jun 2019, 17:55 Richard, <richard@...> wrote:
Whats the most used digital mode on 3cms now ?
--
 Best wishes /73
 Richard Bown

 Email : richard@...

 HTTP  :  http://www.g8jvm.com

 ######################################################################

 Ham Call: G8JVM . QRV: 50-432 MHz + Microwave
 Maidenhead QRA: IO82SP38, LAT. 52 39.720' N LONG. 2 28.171 W
 QRV 6mtrs 200W, 4mtrs 150W, 2mtrs 300W, 70cms 200W,
 Microwave 1296MHz 140W, 2320MHz 100W & 10368MHz 5W
 OS: Linux Mint 19.1 x86_64 Tessa, on a Dell Inspiron N5030 laptop
 ######################################################################





Re: digi modes 3cms

Andy G4JNT
 

JT9H (normal speed version) has a not-much-narrower tone spacing  of222Hz, and a lower baud rate of 1.736Hz  so should be around 3 - 4dB more sensitive.
So well-worth trying.

I used JT4F on the mobile tests (1 Watt to an quadri-helix omni) via QO100 and got near 100% decodes.   See report in June's RadCom
That wouldn't have gone, using JT4F or G



On Mon, 17 Jun 2019 at 20:19, John Worsnop <johnworsnop@...> wrote:
JT4G

73 John

On Mon, 17 Jun 2019, 17:55 Richard, <richard@...> wrote:
Whats the most used digital mode on 3cms now ?
--
 Best wishes /73
 Richard Bown

 Email : richard@...

 HTTP  :  http://www.g8jvm.com

 ######################################################################

 Ham Call: G8JVM . QRV: 50-432 MHz + Microwave
 Maidenhead QRA: IO82SP38, LAT. 52 39.720' N LONG. 2 28.171 W
 QRV 6mtrs 200W, 4mtrs 150W, 2mtrs 300W, 70cms 200W,
 Microwave 1296MHz 140W, 2320MHz 100W & 10368MHz 5W
 OS: Linux Mint 19.1 x86_64 Tessa, on a Dell Inspiron N5030 laptop
 ######################################################################





GB3CSB 23cm faulty - off air

David GM6BIG
 

Hi All,

Just to advise the 23cm part of the GB3CSB cluster is off air.
It is intermittent, and occasionally  reappears.

All the other bands appear normal.
So the common driver should be OK.

I hope to get to site later this week.

Much of the 13cm and 9cm beacon hardware shares the same chassis as the 23cm, so depending what is faulty, they may all need to be turned off or (thanks to a new bit of distribution hardware I was due to fit soon ready for more bands to be added) I may be able to patch in a spare 23cm chassis....

Will keep you all posted.....

73 David GM6BIG

Wanted | Bird 43 13cm element

Timestep
 


Wanted Bird 43 13cm element
 
Bit of a long shot but would like 50W .  The Bird 433-37 seems to be the thing but it isn't on Bird's website ?
 
Any other suggestions ?
 
Thanks
 
Dave G4IUG  Ex G8EAO

Re: Wanted | Bird 43 13cm element

DF6NA Rainer
 

Am 18.06.2019 um 11:15 schrieb Timestep:
Bird 433-37

Google is your friend:
https://www.martinrfsupply.com/store/Search.aspx?searchTerms=433-37&submit=true&type=AND


Re: Wanted | Bird 43 13cm element

Timestep
 



Google is your friend:
 
If only, the search is faulty !
 
Dave  G4IUG  Ex G8EAO