Date   

Re: GB3EDN + JT4G

Dave <dave@...>
 

I don't have much luck receiving GB3EDN, which supports the statement "Not so good south" :-)

However, I've fired up WSJT, pointed the beam towards Edinburgh and will keep lookig to see if anything is decoded.

I really must get the mast head preamp sorted out though...
 
Cheers - Dave (g)DJA)
 
 

----- Original Message -----

 

The 23cm beacon in Edinburgh is now on running JT4G. Its frequency is 1296.990 MHz. I will be interested in signal reports and reports of decodes. The frequency is not GPS locked but is controlled from a good quality reference and was well within 10 Hz of its nominal frequency when I checked last night.

It has a good take-off from SE through to W going anti-clockwise on a map. Not so good due south

Brian GM8BJF


East Sussex/W.Kent

Christopher Bartram <cbartram@...>
 

Is there anyone in East Sussex or West Kent who could give a new 10GHz operator a test signal in the next few days, and perhaps help as an Elmer? If there is, could you drop me an email offline, and I'll put you in touch.

Thanks.

Chris
GW4DGU

email: gw4dgu@chris-bartram.co.uk


LMX2541 PCBs have arrived

Andy G4JNT
 

Another batch of 40 PCBs for the LMX2541 Development board have just arrived.  They're identical to the last lot.
 
 
PCBs can be orded via http://www.g4jnt.com/The_JNT_Shop.htm   and I'll also be bringing some along to Martlesham, along with the optional RS232 interface controller.
 
If you want 3 or more, please contact me direct as price discounting can be negotiated
 
Before too long I'll have a design and PIC code for a rotary encoder / LCD controller for these.  The PCB will be the same as that used for my AD9850DDS controller, http://www.g4jnt.com/AD9850-Controller.pdf   which will connect directly via the 4 way header.    PIC code already exists for such control, but at this stage the output divider cannot be changed via the manual interface.  I'm still pondering about the best way to do that in a clean and simple manner.
 
PIC code for JT65 also exists.
 
Andy
G4JNT

 


GB3EDN + JT4G

Brian Flynn GM8BJF
 

The 23cm beacon in Edinburgh is now on running JT4G. Its frequency is 1296.990 MHz. I will be interested in signal reports and reports of decodes. The frequency is not GPS locked but is controlled from a good quality reference and was well within 10 Hz of its nominal frequency when I checked last night.

It has a good take-off from SE through to W going anti-clockwise on a map. Not so good due south

Brian GM8BJF


Re: Design for Gunnplexer system

Richard Bown <richard@...>
 

On Sun, 14 Apr 2013 11:53:07 +0100
David Kirkby <david.kirkby@onetel.net> wrote:

What do people think about using this as the 88-108 Mhz receiver kit, based
on the TDA7000,

http://www.ebay.co.uk/itm/140600132991
and the accompanying audio amplifier
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=130571695212

with a view to later changing to a 30 MHz IF by returning it to 30 MHz?


Another option, which is even simpler, is this little kit, which has the
audio amp on the same circuit like Peters. It uses a varactor diode for
tuning.

http://www.ebay.com/itm/TDA-7000-FM-RADIO-RECEIVER-88-108MHz-DIY-KIT-/261159434791
That kit has a free running vco, so dont expect it to be very stable, you are much better off using
one of the cheap vhf/uhf handhelds and using the wide band receive function , at least its
synthesised, and more stable, and a lot more sensitive, depending on which HT you use most will
tune WBFM down to 30 MHz so 70 MHz wont be a problem. Those HTs can be got for about £30 ~£40
and they work and do not need building, so you only have the down converter to build. I expect most
of your club members already have these handhelds, or have a kenwood TH-F7 you can have WBFM up to
1300 MHz from HF, why reinvent the wheel when its ready made from China at little more than the
cost of a kit, ???
Also should you take any note of advise given to you by many people to use an LNB , either stand
alone or a Bernie Box many of the VHF/UHF handhelds will cover 600~700MHz WBFM and other modes
The other advantage to using LNBs over a diode mixer with only the antenna gain in front of it is
and extra 30dB of rx gain with a NF below 1dB.

LNBs and cheap Chinese handhelds, or more up market Kenwood and others handhelds, is Cost, time and
easy availability. and still can be done as a club project as the assembly of the front end can be
managed by any of them.

No having to VAT on delivery plus the collection charge by the postal service, Once you purchase
over about £25 you will hit these charges, Between £12 ~ £25 depending on courier/postal service
You can still use a Gunn or simar type Tx, or they can pay around with some cheap LNBs by turning
the fets the FETs, So you have a low cost Tx, you could do a group purchase of pucks.
There are some ancient LNBs around that will pull in to the 10 GHz band , and they can be picked up
for a very low cost.

--
--
Best wishes / 73
Richard Bown

Email : richard@g8jvm.info
HTTP :http://www.g8jvm.info
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QRV VHF 6mtrs 200W, 4 mtrs 150W, 2mtrs 350W, 70cms 200W
Microwave 23 cms 140W, 13 cms 100W, 6 cms 0W & 3cms 5W
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Re: Microwave Society Datapack

Dave <dave@...>
 

I've scanned the rest of the copies of Waveguide and the links are shown below.
 
 
 
 
 
 
I have spotted one thing in the lists of callsigns, G6VNQ should read G6VMQ as that's what my callsign was at that time. :-)
 
Dave (G0DJA)


Re: 10GHz 'wide band'

Geoff Blake <geoff@...>
 

Hello Sam, Group,

The GB3CMS beacon was co-located with GB3DA, GB3ER and a number of other repeaters in the GB7 (data) series. This was under the management of the Essex Repeater Group and incidentally was where I first met Murray.  This was back in the late '80's/early '90's and maybe even earlier. At that time the aerial was a winged version of a slotted waveguide and was colloqually known as "the table-tennis bat". It must have worked as we received reports from as far afield as High Wycombe.  

Unfortunately the site (the tower) no longer exists and I believe the beacon was relocated at the QTH of Clive G1EUC. At about the same time I resigned from the management committee (and membership) of the Essex Repeater Group and have no further info regarding the beacon.

From my point of view, from about 5km away, the re-establishment of the beacon could be useful, I am not sure that John (EAT) would say the same!

Geoff


On 15 April 2013 16:45, Sam Jewell <jewell@...> wrote:
There was a beacon at Danbury.  GB3CMS.  I built it using the 'engineering spare crystal for GB3MHX (suitably pulled to the correct QRG for 'CMS) after the beacon originally built by G4FUF and G4EZP failed and couldn't be got going again. Keith and Ian asked me to help. Maybe Keith or Ian can provide further information for the records?

The original was based on a design in DUBUS. The replacement was based on one of my 004 boards followed by one of Charlie's x4 multipliers and, I think, a low power PA to slotted waveguide antenna. It was an excellent test signal here. GB3MHX was always too strong at this close distance (5km).

Eventually that beacon also had to be replaced and Murray has a nice new beacon on test ( for several years now, I think......) but for whatever reason it has not been moved from its present test location near Chelmsford to its licensed site.
Maybe Murray ( bless him!) will be embarrassed into action and get the beacon back into service!

73 de Sam, G4DDK





Sent tomorrow from my time machine

g4ddk.com
g4ddk.blogspot.com



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<geoff@...>    or   <melecerties@...>
Using Linux: Ubuntu 11.04 on Intel or Debian on UltraSparc
and Apple OS X 10.8.2 Mountain Lion on my Macbook Pro.    
                Avoiding Micro$oft like the plague.
#################################################


Re: Design for Gunnplexer system

Andy G4JNT
 

Please folks..........
 
Building old WB stuff for nostalgic reasons is fair enough, but trying to replicate 30 year old designs with obsolete chips is another thing altogether.
 
If there is one commodity we are not short of these days its VHF gain.   You only need to stuff the output of the mixer diode into a gain stage - its not as if matching and noise performance is needed for this application - and as far as I recall that chip did neither of those very well anyway.
 
And, incidently, if anyone complains that modamps aren't easy to get hold of, RS do the MSA08 (same electrically as MAR-8)   http://uk.rs-online.com/web/p/rf-amplifiers/6933183/    which is the particularly high gain one giving 30dB plus at 100MHz
 
For the grand sum of £1.52 each, or £1.27 for 10 off.
 
'jnt


 

On 15 April 2013 17:07, Lawrence <lawrence@...> wrote:
-----Original Message-----
From: Dave

> In digging through my old files, I have found the Radio Spares datasheet for
> the RS560C !!


I have just looked in my copy of the Plessey Linear IC Handbook, dated September
1988. It includes 5 pages on the SL560C so if anyone needs a copy of that or
other devices from them just let me know.

73, Lawrence  GJ3RAX




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Re: Design for Gunnplexer system

Lawrence <lawrence@...>
 

-----Original Message-----
From: Dave

In digging through my old files, I have found the Radio Spares datasheet for the RS560C !!

I have just looked in my copy of the Plessey Linear IC Handbook, dated September 1988. It includes 5 pages on the SL560C so if anyone needs a copy of that or other devices from them just let me know.

73, Lawrence GJ3RAX


Re: 10GHz 'wide and'

Robert Price <g8dtf@...>
 

Hi Sam

There is WBFM activity "Up North". A number of Bolton Wireless Club members have been using WBFM on both 10GHz and 5.7GHz. Some equipment is of the old Gunnplexor type, but more modern LNB based systems are also used. Work is going on to find alternatives to Gunn TX's. Many of the BWC entries for the SHF UKAC are using WBFM equipment.

73

Bob
G8DTF



From: Sam Jewell
To: "ukmicrowaves@..."
Sent: Sunday, 14 April 2013, 16:51
Subject: [ukmicrowaves] 10GHz 'wide and'

 
Some years ago, when I was writing the Radcom GHz Bands column, I dared mention that there seemed to be a small but significant WBFM revival going on. How wrong I was!
I did get a little correspondence about WBFM advantages and disadvantages, but no mention that anyone was doing anything practical. All talk, no action?

As one of the early adopters of Gunn based WBFM for long distance operation (sheepskin number 5, if I recall correctly) I feel at least a little qualified to comment on the present discussion.

It is my own personal opinion that any individual or group wishing to 'have a go' at 10GHz but not wanting to commit too much money initially, in case they don't wish to go any further, should start not start with a Gunn oscillator ( or Doppler DRO module - in my experience the cheap Chinese Doppler units leave a lot to be desired in terms of stability) but actually start with one of the cheap Sat TV LNBs. In particular Bernie, G4HJW, has identified some very useful ones. With this and a handheld scanner or handheld radio, such as those from Icom , Yaesu or Kenwood. Etc., that have wideband or narrowband AM FM demodulation and cover 618MHz, it should be possible to copy a number of UK beacons from locations that are line of sight or near line of sight and learn a lot about antennas and directivity etc. Such a receiver is likely to have considerably greater sensitivity at 10GHz than any simple Gunn based receiver. And not have the (REAL) stability problems of simple Gunn oscillators.

A club member could maybe build a suitable FM transmitter based on Gunns or other technology to provide a signal, if there are no beacons nearby. In Essex there will soon be a 10GHz beacon at Clacton on Sea and if Murray gets round to it there will be another one at Chelmsford! Martlesham GB3MHX beacon, in Suffolk, should be audible up and down the Essex coast, not to mention a few from the continent due to super refraction over the North Sea, starting later this month.
And by going north, the Cambridge beacon , GB3CAM should also be receiveable from a number of sites in north Essex.

Later, those club members who wished to go further could then build their own versions of the transmitter Gunn, DRO or synthesised to give two-way capability. There are lots of ways in which switching between transmit and receive can be achieved in order to produce a transceiver with a capability well beyond that available to us in the 1970s.

And best of all, club members ( already possessing a suitable scanner) need pay no more than £5 to £10 to get started in this most interesting part of the spectrum. Even the full transceiver need cost no more than £50 in parts and a few hours of building (assuming anyone builds anything these days ; ) )

Maybe someone with this capability already could bring it along to Martlesham in two week's time and demonstrate reception of the Martlesham beacon?

73 de Sam, G4DDK

Sent tomorrow from my time machine

g4ddk.com
g4ddk.blogspot.com




47GHz

Matthew Twyman <matthew.twyman63@...>
 

I am contemplating building for the band and wondered if a DRO from an Amstrad LNB
with the puck ground down might be used to drive a quadrupler to make a signal source.
73
Matthew GW6KOA


Re: 10GHz 'wide band'

SAM JEWELL
 

There was a beacon at Danbury. GB3CMS. I built it using the 'engineering spare crystal for GB3MHX (suitably pulled to the correct QRG for 'CMS) after the beacon originally built by G4FUF and G4EZP failed and couldn't be got going again. Keith and Ian asked me to help. Maybe Keith or Ian can provide further information for the records?

The original was based on a design in DUBUS. The replacement was based on one of my 004 boards followed by one of Charlie's x4 multipliers and, I think, a low power PA to slotted waveguide antenna. It was an excellent test signal here. GB3MHX was always too strong at this close distance (5km).

Eventually that beacon also had to be replaced and Murray has a nice new beacon on test ( for several years now, I think......) but for whatever reason it has not been moved from its present test location near Chelmsford to its licensed site.
Maybe Murray ( bless him!) will be embarrassed into action and get the beacon back into service!

73 de Sam, G4DDK





Sent tomorrow from my time machine

g4ddk.com
g4ddk.blogspot.com


Re: 10GHz 'wide and'

Richard Bown <richard@...>
 

On Mon, 15 Apr 2013 13:39:46 -0000
"Dave" <dave@g0dja.co.uk> wrote:

I read it as just a flippant remark as, obviously, Sam has a well known long history of operating
on, building for, testing and, in the case of some of my gear, repairing a great variety of
different bits of kit.

Dave (G0DJA)
----- Original Message -----

I took it the way the preceding posting where made :(
lets hope it was the last comment like that.




On Mon, 15 Apr 2013 12:52:54 +0100
David Kirkby <david.kirkby@onetel.net> wrote:

> On 14 April 2013 16:51, Sam Jewell <jewell@btinternet.com> wrote:
> > As one of the early adopters of Gunn based WBFM for long distance operation (sheepskin
> > number 5, if I recall correctly) I feel at least a little qualified to comment on the
> > present discussion.
>
> I feel you are well qualified to comment!
>
< CHOPPED>

That is a very worrying comment to see on this list
Does this mean in your opinion that unless you are a Charted Engineer or have a pHD that you


--
--
Best wishes / 73
Richard Bown

Email : richard@g8jvm.info
HTTP :http://www.g8jvm.info
nil carborundum a illegitemis
##################################################################################
Ham Call G8JVM . OS Fedora FC18 x86_64 on a Dell Insiron N5030 laptop
Maidenhead QRA: IO82SP38, LAT. 52 39.720' N LONG. 2 28.171 W ( degs+mins )
QRV VHF 6mtrs 200W, 4 mtrs 150W, 2mtrs 350W, 70cms 200W
Microwave 23 cms 140W, 13 cms 100W, 6 cms 0W & 3cms 5W
##################################################################################
Please do not use the e-mail address of richard@g8jvm.com
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Re: 10GHz tones

Dave <dave@...>
 

 
----- Original Message -----
Back to getting ready for MMRT next week. I hope everyone has now registered? We will be having our final preparation meeting this Thursday, so if there are any special requests, let the organisers know before Thursday.

.

Looks like I wont be going after all. At one stage it looked like my daughter and grand daughter might be moving to Suffolk by now, but that's been put back a few weeks, so it looks like we'll still have Megan on that weekend.
 
Which is a shame, but can't be helped.  I'll log back onto the site and cancel my booking in case there's someone else wanting to put their name down at the last minute.
 
Dave (G0DJA)


Re: 10GHz 'wide and'

Dave <dave@...>
 

I think I already have the bits for this. I bought an LNB (that I was going to hack apart to make a 10GHz front end for the narrowband gear) and I have a RTL (DVB-T) dongle.  As well as a few other assorted SDR boards and systems.
 
I guess all I need to do is figure out what to connect to where...
 
On the hill topping front, my issue these days is time. We have my grand daughter over to stay at weekends so that my daughter can get on with her degree work.  However, as that will be all done by the summer and they will both be moving to Suffolk with my future son-in-law, maybe I'll have a bit more time (famous last words?)
 
Dave (G0DJA)

----- Original Message -----

 

On 15/04/2013 10:34, g4bao wrote:
> I fully agree with Sam's comments and your new RadCom GHz Bands Column will
> have a paragraph on a very simple and cheap receiver idea using an LNB and
> a £15 RTL USB dongle. Typical total cost excluding the PC to run the SDR
> program around £25.
>

I hope it's waterproof and small enough to carry in a small rucksack up
the hills!

Much of the fun of the old wideband days was getting out in the fresh
air and operating from hill and mountain tops with this simple gear.
Don't anyone tell me they you are all too old for this anymore ;-) I'm
not, at almost 76 .... tear yourselves away from the computer screens
gentlemen!

73

Peter, G3PHO


Re: Design for Gunnplexer system

Dave <dave@...>
 

In digging through my old files, I have found the Radio Spares datasheet for the RS560C !!
 
If anyone wants a copy please email me.
 
Kate says that she's not surprised by the junk and old paperwork that I keep, only that I never seem able to remember where I put it...
 
Dave (G0DJA)

----- Original Message -----
 

You'd do an awful lot better using a 50 ohm modamp lilke a MAR-6 instead of a really ancient hard to get-hold-of  chip like that.
 
I junked my stocks of them a few years ago to release the storage space.
They weren't even a very easy to use gain stage
 
Andy  G4JNT

On 14 April 2013 18:15, Richard Bown <richard@...> wrote:
 

On Sun, 14 Apr 2013 16:57:14 +0100
"Alan Melia" <Alan.Melia@...> wrote:

> Hi Dave , and Dave :-)) You might have trouble finding reference to an
> RS560 now, this was in the days wheh RadioSpares (Whoops ...showing my
> age....RS Components) insisten on renumbering their semiconductors with
> their own type numbers......very confusing. The actual component is a
> Plessey SL560 I believe....which you will find referenced anf might even
> find a data sheet for.
>


Re: 10GHz 'wide and'

Dave <dave@...>
 

I read it as just a flippant remark as, obviously, Sam has a well known long history of operating on, building for, testing and, in the case of some of my gear, repairing a great variety of different bits of kit.
 
Dave (G0DJA)

----- Original Message -----

 

On Mon, 15 Apr 2013 12:52:54 +0100
David Kirkby <david.kirkby@...> wrote:

> On 14 April 2013 16:51, Sam Jewell <jewell@...> wrote:
> > As one of the early adopters of Gunn based WBFM for long distance operation (sheepskin number
> > 5, if I recall correctly) I feel at least a little qualified to comment on the present
> > discussion.
>
> I feel you are well qualified to comment!
>
< CHOPPED>

That is a very worrying comment to see on this list
Does this mean in your opinion that unless you are a Charted Engineer or have a pHD that you


Re: 10GHz 'wide and'

Peter Day <microwaves@...>
 

On 15/04/2013 10:34, g4bao wrote:
I fully agree with Sam's comments and your new RadCom GHz Bands Column will
have a paragraph on a very simple and cheap receiver idea using an LNB and
a 15 RTL USB dongle. Typical total cost excluding the PC to run the SDR
program around 25.

I hope it's waterproof and small enough to carry in a small rucksack up the hills!

Much of the fun of the old wideband days was getting out in the fresh air and operating from hill and mountain tops with this simple gear. Don't anyone tell me they you are all too old for this anymore ;-) I'm not, at almost 76 .... tear yourselves away from the computer screens gentlemen!

73

Peter, G3PHO


Re: 10GHz 'wide and'

Dave <dave@...>
 


 
I also seem to remember a story that Glen told about using copper pipe with an inverted cone placed at the top to scatter RF in all directions.
 
However I didn't actually ever see it being done.
 
Dave (G0DJA)

----- Original Message -----

 

Glen G8MWR once told me that there was a group in the Wolverhampton area using 22mm Cu water pipe as Alford
slots on 10 GHz as a local chat band. Anyone on here know any more about this?

BTW I believe Val his wife is still living at the same address. She retired from teaching at the school we both taught
in sometime ago ( so did I for that matter!).

de John G8SEQ


Re: 10GHz 'wide and'

Richard Bown <richard@...>
 

On Mon, 15 Apr 2013 12:52:54 +0100
David Kirkby <david.kirkby@onetel.net> wrote:

On 14 April 2013 16:51, Sam Jewell <jewell@btinternet.com> wrote:
As one of the early adopters of Gunn based WBFM for long distance operation (sheepskin number
5, if I recall correctly) I feel at least a little qualified to comment on the present
discussion.
I feel you are well qualified to comment!
< CHOPPED>

That is a very worrying comment to see on this list
Does this mean in your opinion that unless you are a Charted Engineer or have a pHD that you
consider comments made by members of this group are unworthy of making suggestions.
It does look like the many years of experience that all the group members have is irrelevant.
The combined microwave experience must be close to 1000 years, if you take the average age and
the time spent either working in an RF , or the time each person has held their licence for.,
And that's just in the UK. I've notice on both reflectors you ask the same question and do not
seem to take any notice of comments and suggestions
I hope the comment you have made is badly phased , I would be very disappointed to see this list
made elite by professional qualification . I hope I'm wrong , but I fear not.

--
--
Best wishes / 73
Richard Bown

Email : richard@g8jvm.info
HTTP :http://www.g8jvm.info
nil carborundum a illegitemis
##################################################################################
Ham Call G8JVM . OS Fedora FC18 x86_64 on a Dell Insiron N5030 laptop
Maidenhead QRA: IO82SP38, LAT. 52 39.720' N LONG. 2 28.171 W ( degs+mins )
QRV VHF 6mtrs 200W, 4 mtrs 150W, 2mtrs 350W, 70cms 200W
Microwave 23 cms 140W, 13 cms 100W, 6 cms 0W & 3cms 5W
##################################################################################
Please do not use the e-mail address of richard@g8jvm.com
Mail hosted by 1and1, Domain screwed up by 1and1 and Freeparking