Date   

Re: duel band feed

Andy G4JNT
 

You mean "who is fighting whom"



On Fri, 6 Mar 2020 at 18:36, SAM JEWELL via Groups.Io <jewell=btinternet.com@groups.io> wrote:
Duel band? So who is fighting who? 
Sam



Re: duel band feed

SAM JEWELL
 

Duel band? So who is fighting who? 
Sam



Re: duel band feed

KENT BRITAIN
 

I have some antennas that work as 4 and even 5 band feeds.

The 2-11 GHz Log Periodic makes a simple 4 band feed.
The 1.5-15 GHz Vivaldi works at reduced gain down to 800 MHz
so works with modest efficiency on the 23 cm band.   Been using
them for 25 years as dish feeds.  Sam, G4DDK has a supply.  Kent  

On Friday, March 6, 2020, 7:39:22 AM CST, steve turner via Groups.Io <steveturner249@...> wrote:


Hi guys
looking for information on a duel feed for 3cm and 9cm on 1 dish its a 85cm offset dish. iam having problems trying to put 2 dishes up portable had offer of help
from neil G4DBN if we can find something suitable , keith ODA kindly informed me there is an article somewhere in a past issue off scatterpoint , but i cant find it any ideas on a solution to my problem i would be greatful.
thanks steve


Re: SPID RAK

Dave
 

What exactly is a VDR? voltage dependent resistor?
David G4GLT 


On 6 Mar 2020, at 17:56, Dominique Dehays <f6dro@...> wrote:



Hi all ,


yes , I have soldered VDR bougth on Ebay directly in the rotator  box , up the mast. Unfortunately I don't remember wich type it was exactly and as it was a loooooong time ago , it is no longer available in my Ebay history.

73

Dom

Le 06/03/2020 à 18:13, Neil, G3RIR via Groups.Io a écrit :
I have a SPID RAK Rotator and it works fine except that it creates an enormous RF racket on at least 2m. It is so bad that that I cannot peak weak signals.

Dom made a comment that this can be cured by using VDR. Dom or others please expand on that point. I expect to be back on 1296 soon so I really need to improve things.

Neil G3RIR


Re: SPID RAK

Steve G4HTZ
 

I have the spid RAU and that is just as bad as you describe on 6 4 2 meters ....but no interference on 23cms or 10ghz .
would also be interested in a cure .
my RAU is about 5 years old so things may have improved.....but probably not !! 
--
Steve G4HTZ 
JO01JN

23cms 350w to 36 element 
10ghz 12w 80cm dish 
24ghz 1.8w 80cm dish 

currently not active due to house move 


Re: SPID RAK

Dominique Dehays
 

Hi all ,


yes , I have soldered VDR bougth on Ebay directly in the rotator  box , up the mast. Unfortunately I don't remember wich type it was exactly and as it was a loooooong time ago , it is no longer available in my Ebay history.

73

Dom

Le 06/03/2020 à 18:13, Neil, G3RIR via Groups.Io a écrit :
I have a SPID RAK Rotator and it works fine except that it creates an enormous RF racket on at least 2m. It is so bad that that I cannot peak weak signals.

Dom made a comment that this can be cured by using VDR. Dom or others please expand on that point. I expect to be back on 1296 soon so I really need to improve things.

Neil G3RIR


Re: duel band feed

Mike Willis
 
Edited

You could try something like the W1GHz dual band 24/10 GHz feed appropriately re-scaled for 10/3.4 GHz. Basically, design a 9cm horn feed and instead of a back short have a length of waveguide for 3cm. Use a stepped horn so the 3 cm and 9cm beamwidths are comparable.
--
Mike G0MJW

Noted subject change. Can't have two bands fighting each other.


SPID RAK

Neil, G3RIR
 

I have a SPID RAK Rotator and it works fine except that it creates an enormous RF racket on at least 2m. It is so bad that that I cannot peak weak signals.

Dom made a comment that this can be cured by using VDR. Dom or others please expand on that point. I expect to be back on 1296 soon so I really need to improve things.

Neil G3RIR


G4BAO 70 and 23cm driver kits at Cardiff RT tomorrow

John Worsnop
 

I will be have 5 of each of the above kits for sale at the Cardiff Uni Round Table tomorrow. I'm coming by train so can't carry much.
They are at the special RT cash price of £25 for the 70cm driver and £20 for the 23cm driver.

Nab me on Saturday if you want kit(s)

Looking forward to catching up with as many people as I can on the day. Come and bend my ear about what you'd like to see in the RadCom GHz bands column, and, even better, offer some content!

73
John 


Re: dual band feed

Neil Smith G4DBN
 

Yeah, but the mad pursuit of engineering perfection (and UKAC points) is *SO* much more fun than simple, sensible, practical solutions, innit?

Neil G4DBN

On 06/03/2020 14:45, John Worsnop wrote:
I do the same thing. Works for me.

73 John

On Fri, 6 Mar 2020, 14:25 davidm0ghz, <m0ghz.david@...> wrote:
Steve,

I use a separate 9cm feed attached to the side of my 6/3cm feed. There is a 10 degree offset, but it's a simple solution. The design by John G3XDY was  published in the microwave newsletter Oct 2001.  See attached.
-- 
Neil
<a href="http://g4dbn.uk/"><small>g4dbn.uk</small></a>


Re: dual band feed

John Worsnop
 

I do the same thing. Works for me.

73 John

On Fri, 6 Mar 2020, 14:25 davidm0ghz, <m0ghz.david@...> wrote:
Steve,

I use a separate 9cm feed attached to the side of my 6/3cm feed. There is a 10 degree offset, but it's a simple solution. The design by John G3XDY was  published in the microwave newsletter Oct 2001.  See attached.


Re: duel band feed

Neil Smith G4DBN
 

I was wondering about a 22mm round w/g with an HB9PZK lens for 10GHz, then a ring or patch or even a concentric horn for 3.4, but a POTY-style patch would need to be oblong, as otherwise the patch would be too narrow to feed.  I've had a bash at modelling it, but I wonder if there is a better solution.  Steve's dish isn't huge, so there isn't a lot of room, but the engineering can be as complex as a complex thing, we just need some ideas for dual-band 3/9cm feeds on the same axis.  Dish f/d is around 0.65 I think.  Perhaps a ring feed/reflector disk and beam-forming ring? 

This doesn't have to be easy to make, or use easily-available plumbing bits, I can throw the full weight of machining tech at it.  Ideally we don't want to make any performance compromises.  Key design driver is that  I am trying to ensure that Steve can stay in his nice warm car instead of having to mess about swapping feeds in the horizontal sleet storms of an English summer.

Neil G4DBN

On 06/03/2020 13:39, steve turner via Groups.Io wrote:
Hi guys
looking for information on a duel feed for 3cm and 9cm on 1 dish its a 85cm offset dish. iam having problems trying to put 2 dishes up portable had offer of help
from neil G4DBN if we can find something suitable , keith ODA kindly informed me there is an article somewhere in a past issue off scatterpoint , but i cant find it any ideas on a solution to my problem i would be greatful.
thanks steve
-- 
Neil
<a href="http://g4dbn.uk/"><small>g4dbn.uk</small></a>


Re: dual band feed

davidm0ghz
 

Steve,

I use a separate 9cm feed attached to the side of my 6/3cm feed. There is a 10 degree offset, but it's a simple solution. The design by John G3XDY was  published in the microwave newsletter Oct 2001.  See attached.


duel band feed

steve G1PPA
 

Hi guys
looking for information on a duel feed for 3cm and 9cm on 1 dish its a 85cm offset dish. iam having problems trying to put 2 dishes up portable had offer of help
from neil G4DBN if we can find something suitable , keith ODA kindly informed me there is an article somewhere in a past issue off scatterpoint , but i cant find it any ideas on a solution to my problem i would be greatful.
thanks steve


Re: UK Microwave Group - Low Band Contest - March 8th

steve G1PPA
 

hi all hoping to get first qso on 3.4 on sunday 

callsign: G1PPA/P
Locater: IO93RI
bands : 3400 15w o.85m dish
            1296 10w 67 ele
time intend to start 10 ish on 3400 until 12
then 1296 to the end if no wind i will try and get dish and beam up together
will be on on4kst


Re: UK Microwave Group - Low Band Contest - March 8th

Martin - GM8IEM
 

Further to my last message: this morning was calm and sunny, so I took the opportunity to check the TX feed on the 13cm system and it all seems to be working OK - I should have at least 30 watts at the antenna terminals when on full throttle.

If anyone would like a sked before the contest on Sunday, please let me know.

73, Martin

GM8IEM – IO78HF

 

 

From: UKMicrowaves@groups.io On Behalf Of Martin - GM8IEM
Sent: 05 March 2020 09:48
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] UK Microwave Group - Low Band Contest - March 8th

 

Hi John,

I plan to be active as follows:

Callsign: GM8IEM

Locator: IO78HF

Bands:  1.3GHz 180W 60 el

2.30 & 2.32GHz 80W 67 el*

Talkback: ON4KST

Times: Throughout the event

*(only if I can get the antenna feed coax repaired before the contest – at the moment the TX output isn’t getting to the antenna.  The RX side is operational, so maybe the possibility of half points for one‐way (i.e. crossband) contacts if that remains the case?)  

The latest version of AirScout will help me to keep an eye out for aircraft scatter possibilities on multiple paths simultaneously.  Let’s hope there are some decent planes about, although the demise of Flybe doesn’t help .  I can usually work stations as far south as Yorkshire with a suitable plane, and beyond under the right conditions.

73, Martin

GM8IEM

 

-----Original Message-----
From: UKMicrowaves@groups.io On Behalf Of John Quarmby via Groups.Io
Sent: 29 February 2020 17:19
To: UKMicrowaves@groups.io
Subject: [UKMicrowaves] UK Microwave Group - Low Band Contest - March 8th

 

The first UKuG contest of 2020 takes place next Sunday 8th March, from

1000 - 1600 GMT, on the 1296, 2300, 2320, and 3400MHz bands.

 

Full rules are here:

https://microwave.rsgbcc.org/cgi-bin/contest_rules.pl?year=2020&contest=lb_contest

 

I can collate information on your planned operation and produce an activity list next Saturday from inputs received up to early Saturday.

Please use this format:

 

Callsign: G3XDY

Locator: JO02OB

Bands: 1296MHz  400W 4 x 23ele

             2300MHz  200W 0.8m dish

             2320MHz  200W 0.8m dish

             3400MHz  20W 0.8m dish

Talkback: Direct CQ on 1296MHz, ON4KST

Times: Various throughout

 

73

 

John G3XDY

UKuG Contest Manager

 

 

 


Re: Cardiff Roundtable March 7: Mesh networks, beacons, GaN, HD Video, Amplifiers

Derek Kozel
 

Hi Neil,

We're recording the talks of all speakers who agree to be filmed. They'll go up on our YouTube channel once they're rendered. Admittedly we're still working on the last one from the 2019 Roundtable, but I think we'll be a lot faster this time around!

Here's the playlist from last year.
https://www.youtube.com/playlist?list=PLWcPCA66IpF06CYFTGE3nPYe4kqZ8oDlW

On 05/03/2020 22:52, Neil Smith G4DBN wrote:
Ref Raynet: Interesting example locally this week of what happens when the cellphone network dies and then the emergency services radio system stops working, and all the roads are under water and the power is off, and the landlines aren't working and there is no internet service and the water just keeps coming. Local Raynet group were called out and provided comms for the police and ambulance and council during the flooding, and as the local 4x4 response volunteers had the foresight to get licenced and work with Raynet, things went smoothly.  I guess the folks who sold the radio system will make some weedy excuse about nobody telling them it had to work with the kit under water and without mains power.  I heard a rumour that the fire service had, er, "forgotten" to scrap their old low-band VHF sets when the fabby new system went live, so they managed nicely as a result. Now if the local Raynet group also had a mesh network and an uplink from an area with internet and power, they could have provided an even better service.

Are the talks going to be recorded or streamed?
Neil G4DBN


Re: Cardiff Roundtable March 7: Mesh networks, beacons, GaN, HD Video, Amplifiers

Paul G8KFW
 

Hi could they be streamed  also the comments from the audience

 

Alternatively if the presentation is available in electronic format could that be made available

 

Paul

 

 

 

From: UKMicrowaves@groups.io [mailto:UKMicrowaves@groups.io] On Behalf Of Neil Smith G4DBN
Sent: 05 March 2020 22:53
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Cardiff Roundtable March 7: Mesh networks, beacons, GaN, HD Video, Amplifiers

 

Ref Raynet: Interesting example locally this week of what happens when the cellphone network dies and then the emergency services radio system stops working, and all the roads are under water and the power is off, and the landlines aren't working and there is no internet service and the water just keeps coming. Local Raynet group were called out and provided comms for the police and ambulance and council during the flooding, and as the local 4x4 response volunteers had the foresight to get licenced and work with Raynet, things went smoothly.  I guess the folks who sold the radio system will make some weedy excuse about nobody telling them it had to work with the kit under water and without mains power.  I heard a rumour that the fire service had, er, "forgotten" to scrap their old low-band VHF sets when the fabby new system went live, so they managed nicely as a result. Now if the local Raynet group also had a mesh network and an uplink from an area with internet and power, they could have provided an even better service.

Are the talks going to be recorded or streamed?
Neil G4DBN

No virus found in this message.
Checked by AVG - www.avg.com
Version: 2016.0.8048 / Virus Database: 4793/15886 - Release Date: 08/14/18
Internal Virus Database is out of date.


--
Paul Bicknell G8KFW   South Coast UK


Re: Cardiff Roundtable March 7: Mesh networks, beacons, GaN, HD Video, Amplifiers

Neil Smith G4DBN
 

Ref Raynet: Interesting example locally this week of what happens when the cellphone network dies and then the emergency services radio system stops working, and all the roads are under water and the power is off, and the landlines aren't working and there is no internet service and the water just keeps coming. Local Raynet group were called out and provided comms for the police and ambulance and council during the flooding, and as the local 4x4 response volunteers had the foresight to get licenced and work with Raynet, things went smoothly.  I guess the folks who sold the radio system will make some weedy excuse about nobody telling them it had to work with the kit under water and without mains power.  I heard a rumour that the fire service had, er, "forgotten" to scrap their old low-band VHF sets when the fabby new system went live, so they managed nicely as a result. Now if the local Raynet group also had a mesh network and an uplink from an area with internet and power, they could have provided an even better service.

Are the talks going to be recorded or streamed?
Neil G4DBN


Re: Connector ID please?

Derek Kozel
 

Looks like SMP to me?

On 05/03/2020 20:33, Wilko wrote:
I just received 2 surplus 13cm PA from Poland which have coax connectors as show below. Is this a standard connector type? My junk box did not have anything that fits. Suggestions most welcome!

73 Wilko


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