Date   

Re: 10Ghz in EI today... update!

Dave Ackrill <dave.g0dja@...>
 

Tony Gallagher wrote:
I headed to IO52MT on Woodcock Hill Limerick, unfortunately no qso was possible here, distance was about 130Km and we were both over 600-700ft ASL. I was a little disapointed!
What was interesting was we both heard each on very quick burst on FM, about S6, The bursts were about 5 seconds and had alot of very very fast fluttering. I wonder was this tropo or some sort of scatter?
130km is a bit ambitious for a first contact, and the propagation you describe sounds very like aircraft scatter.

If it had been rain scatter, that would sound more like an Aurora signal.

The classic way to describe aircraft scatter is that you hear a 'chuff, chuff' type of noise. Often described as being like an old steam train moving away from a station.

Dave (G0DJA)


Re: 10Ghz in EI today... update!

Tony Gallagher <tony_g_ireland@...>
 

Perfect,
Thanks Richard


Tony

--- In ukmicrowaves@..., "Richard Newstead" <g3cwi@...> wrote:

--- In ukmicrowaves@..., "Tony Gallagher"
I think my next purchase is a cw beacon keyer for setting up. Can >anyone recommend something cheap?
http://www.hamgadgets.com/store/product_info.php?products_id=89

73

Richard
G3CWI


Re: 10Ghz in EI today... update!

Richard Newstead <g3cwi@...>
 

--- In ukmicrowaves@..., "Tony Gallagher"
I think my next purchase is a cw beacon keyer for setting up. Can >anyone recommend something cheap?
http://www.hamgadgets.com/store/product_info.php?products_id=89

73

Richard
G3CWI


10Ghz in EI today... update!

Tony Gallagher <tony_g_ireland@...>
 

Hi everyone,
Worked EI3IX/EI7FAB/P today from Galway IO53PK or there abouts. They were in IO53LU
Distance was about 50-60Km. Signals 9+ were exchanged. Tried FM on 10Ghz for the first time today, which was pretty nice!
I headed to IO52MT on Woodcock Hill Limerick, unfortunately no qso was possible here, distance was about 130Km and we were both over 600-700ft ASL. I was a little disapointed!
What was interesting was we both heard each on very quick burst on FM, about S6, The bursts were about 5 seconds and had alot of very very fast fluttering.
I wonder was this tropo or some sort of scatter?

For setting the dishes bearing, I used Martyns method of standing infront of the dish. This worked perfectly!!! Thanks for that.

I think my next purchase is a cw beacon keyer for setting up. Can anyone recommend something cheap? I'm getting hoarse calling and calling!!

Regards

Tony
EI4GHB


Re: beam and coax

Julie & Stephen <stephen_hayman@...>
 

Hello Chris - if you new to 23cm then *welcome* - it is one of the best microwave bands..
 
Keep the *rule of thumb* for any coax loss at 1dB or less - not sure of antenna prices in the UK but here in ZL we build our own, because we can't buy them locally  - a loop Yayi - 33 elements will work great - cost to build is about 5 pound. A days work to cut the strips and mount on a 19mm boom. They are not critical in dimensions - the word would be less forgiving as compared to say a Yagi design.
 
Get something up in the air first - I used for many year a single loop Yagi and only 25 watts and had some great internal ZL contacts (350km) and beacons (550km) including VK many times at (2100km) portable - so when the troposheric ducting is in, she is magic..
 
The good thing about 23cm, you can work many to begin with, and over time you can upgrade your station. It's an active band. Since my days of 25 watts and a loop Yagi (and a lot of activity growth) have upgraded to 150 watts (W6PQL) and a stack of 4 Yagi's(120 elements) in total. That really helped with my limited home station QTH...
 
Cheers - Steve
 
 
 

 --- On Sat, 8/8/09, Chris wrote:

From: Chris
Subject: [ukmicrowaves] beam and coax
To: ukmicrowaves@...
Received: Saturday, 8 August, 2009, 9:28 PM

 
Hi I have just put the 23cm unit into my IC910 and I need some help with what beam and coax to use on the 23cm band
thanks Chris GM4YLN


Re: beam and coax

g4bao
 

Hello Chris,
The WIMOs are quite pricey, but I've heard nothing but good said about them. I use four 23 element Tonnas, but ran a single one for many years. They are a little fragile but have the advantage (if you live surrounded by neighbours like I do) that the visual impact is less than most Freeview TV antennas. Also if you had plans for higher bands, a 45cm sky Dish fits INSIDE a box of four Tonnas (have a look on www.g4bao.com for a picture of my setup) giving you a nice multiband setup with minimum space.

As for feeder, I echo Graham, FSJ450 or LDF450 works well, but if you can get the PA and preamp on the mast, you can use UR67. I have a masthead preamp and use UR67 as downlead  for receive, and I also diplex the 144MHz IF for 3cms down the same coax. I have a separate TX feed of FSJ4-50 as my PA is in the loft.

There are many combinations of antenna gain and feeder loss possible so you need to get your calculator out and work out what suits your particular location best.

73
John             
-- 
G4BAO
QRV 23,9,3 and 1.2cm
Beacon keeper GB3CAM/24GHz
http://www.g4bao.com 


Re: beam and coax

John Quarmby
 

Hi Chris

It all depends....

How much space do you have on your mast for the antenna? If it is limited then a single long yagi would be a good bet (eg the 67 ele Wimo/SHF or 55ele Tonna). If you have the vertical space available, stacked shorter yagis will give more horizontal beamwidth and similar gain (eg 2 x 44ele or 28ele Wimo's or 2 of the 23/35 ele Tonnas). I have used a box of four 23 ele Tonnas for for many years with good results.

As for coax, it depends on how long a run you need and the weight involved, obviously the lower loss the better from an RF viewpoint. If you can find some Andrew LDF4-50 that would be ideal, but it's too rigid for a loop round a rotator, where FSJ4-50 or the Ecoflex cables would work better. Ecoflex (10 or 15mm) may also be worth considering for the main run. Avoid RG213/UR67 as its loss is high at 1.3GHz. To some extent you can trade off feeder loss against more watts in the shack if you use a masthead preamp.

A good masthead preamp is well worthwhile, the choice of design may depend on whether you have any cellular base stations in your immediate vicinity.

73

John G3XDY

----- Original Message -----
From: "Chris" <chris.yln@...>
To: <ukmicrowaves@...>
Sent: Saturday, August 08, 2009 9:28 AM
Subject: [ukmicrowaves] beam and coax


Hi I have just put the 23cm unit into my IC910 and I need some help with what beam and coax to use on the 23cm band
thanks Chris GM4YLN



------------------------------------

Yahoo! Groups Links



Re: beam and coax

Graham - G4FSG
 

--- In ukmicrowaves@..., "Chris" <chris.yln@...> wrote:

Hi I have just put the 23cm unit into my IC910 and I need some help
with what beam and coax to use on the 23cm band
thanks Chris GM4YLN
Chris

I use a Wimo 44 element on 23cms (and Wimo antennas on 70cm and 2m) and
have found it very good in both performance and quality. Of course, the
general rule is 'get as much metal in the sky as possible' so a 67 el
would be even better!!

The answer to 'what feeder' is more difficult - it depends to a degree
on the length of feeder and whether you are going to run a masthead
pre-amp. A fair compromise is Ecoflex 10 or 15 depending on the length.
Even better would be LDF4-50 (but only just better than Eco15 at 23cm).
Under lift conditions then any of these will be OK however long the run
but if you want to work DX under flat condx then a masthead preamp
(G4DDK?) and reasonable power out is needed.

73

Graham - G4FSG


Re: Beacons and gardening

Willis, MJ (Michael) <mike.willis@...>
 

The same thing happens with shacks when amateurs are on the air rather than gardening. It is just as well overgrown trees are good supports for HF stealth dipoles.
 
Thinking of weeding, I will be bringing some stuff to the Hamfest on Sunday, I need to clear out a bit. I will have the odd microwave transverter, an HP8557 and an Altech noise figure meter might be of interest to those coming. The good thing about Hamfest is that it is wide ranging in an area with many microwave enthusiasts but not on the East coast where there appears to be a surplus of surplus.
 
Several things I will not bring as they raise too little cash nowadays - what does one do with VHF valve linears these days for example? They are practically obsolete for powers below about 150W and running more than 200W from most homes disturbs nearby electronic equipment. There must be thousands in cupboards, under beds, in sheds and in garages all over the country. I appear to have several and doubt I am untypical. Too heavy to take and bring back.
 
Mike

--
Scanned by iCritical.



Re: beam and coax

G3RIR <g3rir@...>
 

Ecoflex 15 is very easy to handle and the loss is very nearly as good as
LDF450. You will probably need a mast head pre-amp unless your coax run is
very short.

I use a 35 ele Tonna but I suggest you get something a big bigger and more
robust.

Neil, G3RIR

-----Original Message-----
From: ukmicrowaves@... [mailto:ukmicrowaves@...] On
Behalf Of Chris
Sent: 08 August 2009 10:28
To: ukmicrowaves@...
Subject: [ukmicrowaves] beam and coax

Hi I have just put the 23cm unit into my IC910 and I need some help with
what beam and coax to use on the 23cm band
thanks Chris GM4YLN



------------------------------------

Yahoo! Groups Links


beam and coax

Chris
 

Hi I have just put the 23cm unit into my IC910 and I need some help with what beam and coax to use on the 23cm band
thanks Chris GM4YLN


Re: Beacons and gardening

Bill <radio.m@...>
 

In message <4A7CBEF2.6030001@...>, David Wrigley
<zen130696@...> writes
 

Hi Andy

We've just bought a shredder to carry out a similar operation. I've
been really surpised at how much the bulk is reduced by shredding. It
will be interesting to see whether the chipped wood keeps down future
growth. It certainly removes any need to remove the cut branches from
site - recycling in action!
73 David G6GXK
On a similar note, I had a site that I looked after for a number of
years that had a wire mesh fence around it and razor wire on top. As
added security there were brambles growing on all sides. With only
minimal management the blackberries made good eating. Those coming
through the inside of the fence were kept away from Joe public and were
a perk of the job Just remember the old adage of "don't pick/eat
blackberries that grow below knee height!! :-)
--
Bill


Re: Beacons and gardening

David Wrigley <zen130696@...>
 

Hi Andy

We've just bought a shredder to carry out a similar operation. I've been really surpised at how much the bulk is reduced by shredding. It will be interesting to see whether the chipped wood keeps down future growth. It certainly removes any need to remove the cut branches from site - recycling in action!

73 David G6GXK




Andy Talbot wrote:

One disadvantge of maintaining a beacon on a remote site, is that
every so often you have to go up there and clear away the foliage...
This is what the Bell Hill site looked like after three years of
growth - see how the concrete cabin is buried in greenery - and the
fruits of our labours.
http://www.scrbg.org/beacon/ [scroll about two-thirds of the
way down, to the gardening session.]
Don't forget to visit the SCRBG stand at the FRARS Hamfest on Sunday.
http://www.frars.org.uk/cgi-bin/render.pl?pageid=1358
All donations to the upkeep of the beacons will be greatfully accepted
(but no gardening tools, please)
Andy
obo. www.scrbg.org
-


Re: FT-817 use with transverters

Andy Talbot <andy.g4jnt@...>
 

The input protection relay contacts are the wrong side of the detector
controlling it.

I drew the design up and initially laid-out the PCB like that,
realised the mistake and corrected things on the finished module. But
then, unfortunately, sent the old diagrams for publication. Just one
reader spotted the error - almost immediately.

Andy
www.g4jnt.com



2009/8/6 Paul Whatton <paul@...>:



Scratching my had looking for the deliberate mistake.... The values seem
to be for a 6dB rather than a 5dB attenuator as described in the text
but I bet that's not it?

Paul



The interface was published in RadCom around about 1994. Can't check
which edition at the moment (at work) but will do so this evening.
Incidently there's an error in the circuit diagram as published -
kudos to the first to spot it.

Andy
www.g4jnt.com


Beacons and gardening

Andy Talbot <andy.g4jnt@...>
 

One disadvantge of maintaining a beacon on a remote site, is that
every so often you have to go up there and clear away the foliage...
This is what the Bell Hill site looked like after three years of
growth - see how the concrete cabin is buried in greenery - and the
fruits of our labours.
http://www.scrbg.org/beacon/ [scroll about two-thirds of the
way down, to the gardening session.]

Don't forget to visit the SCRBG stand at the FRARS Hamfest on Sunday.
http://www.frars.org.uk/cgi-bin/render.pl?pageid=1358

All donations to the upkeep of the beacons will be greatfully accepted
(but no gardening tools, please)

Andy
obo. www.scrbg.org


Re: 24GHz in GW

Martyn G3UKV
 

Hi Dave
Your nearest bcn on 24 GHz is probably GB3ZME in IO82RP. 1 watt PA, 10+10 slot. It got a bump during erection, so  nominal freq.( 24048.910) has gone a bit AWOL - around 24,048.780 at present. Audible widely in Midlands /P sites, and as far north as Winter Hill at least.
I'll go out /P any time I'm available if there's a reasonable chance of a QSO on 24G too.
 
73 Martyn G3UKV
 

----- Original Message -----
Sent: Friday, August 07, 2009 12:08 PM
Subject: Re: [ukmicrowaves] 24GHz in GW

 

Christopher Bartram wrote:
> Hello Dave
>
> Croeso y Gymru!
>
> It's very good to see that you are prepared to bring 24GHz gear to Wales :-)
>
> I suggest that you look for the GB3AMU beacon, or drop an email to Keith,
> GW3TKH...

It might be the 1st opportunity to test the receiver out. The two other
alternatives are GB3MAN, which means a trip up to a spot just off the
M62 westbound to get a LoS shot. The other, GB3CAM, means a trip down
the A1 to get to a suitable location.

I'll see if I can find an email for TKH and will let him know that I
will be about.

If anyone else on the reflector will be about for 3cm or 12mm, I'll take
a small 2M/70cm antenna for talkback. KST relies upon a Vodaphone
signal for the laptop and seeing the screen in daylight (I was going to
say sunlight, but given the summer we've had so far...) but I will try
setting it up as well.

Dave (G0DJA)


Re: Dish alligment...

Martyn G3UKV
 

Hi Tony
Depending on your dish, of course, I sight facing INTO the dish (much easier than peering from behind the dish). Don't TX yet, of course !), but allow for magnetic variation. (about 4 deg. at present). eg. Station at 90deg, set compass to 94 deg. Use 'wrong' end of compass needle as you sight facing the dish. 1-2 deg. accuracy is quite easy, with a little care and practice, whether it is a prime focus or offset-fed dish.
 If possible have a compass rose mounted in some way on the tripod or mast.  There are cheap plastic 360 deg. protractors available from stationers - but probably remove any strengthening plastic in the middle bit which usually gets in the way ! Once you have heard a station or beacon on a known bearing, indicated on the protractor, all other bearings are then perfectly accurate. So in theory, at least, you only have to get one stn/bcn on a known bearing to be set up for the duration of your /P activity.
 
73 Martyn G3UKV
P.S. Sri no sigs. hrd last night. Will persevere.
 

----- Original Message -----
Sent: Thursday, August 06, 2009 10:51 PM
Subject: [ukmicrowaves] Dish alligment...

 

Hi,
I hope this isnt a silly question, but how are you all positioning your dishes? I have a marine compass with a sight so I know exactly where I need to point the dish on the horizon.
The problem is, I'm finding it hard to gauage what the dish is pointing to. I'm sure I'm accurate within 20degrees or so.
Has anyone come up with any clever way of alligning the dish more accurately?

Thanks everyone

Tony
EI4GHB


Re: South Yorkshire Microwaves Round Table - photos uploaded

Martyn G3UKV
 


Hi Bernie
Thanks for the info. We had hoped to interest Telford  &DARS members into building the project. Last winter we had 3 separate building projects, and around 10-12 members built each (ie ~30 projects constructed). So at SYorks  RT we put our names down for a number of kits, whilst construction interest is reasonably high. Guess it will have to be for 2010.
Anyway, pse keep us in mind.
73  Martyn G3UKV (o/b/o TDARS)
 

----- Original Message -----
From: bernie
Sent: Thursday, August 06, 2009 10:36 PM
Subject: Re: [ukmicrowaves] South Yorkshire Microwaves Round Table - photos uploaded

 

There's not much of an update, I'm afraid Darren. I have been sourcing
the 10 MHz TCXO, and it looks like buying direct from the distributer is
about three times cheaper than waiting for an ebay 'bargain'. The same
board also can act as a low power tx driver just by swapping a 14.4 MHz
TCXO for the 10 MHz one - no other rf changes, but I need to add a
modulation input before ordering more boards - it's really a winter
project, so expect something in the new year (it might even be spring
before it's all updated and components bought).

Sorry I'm not any quicker than that.

Bernie

Storer, Darren wrote:
>
>
> Hi Bernie,
>
>
> mny tnx - that works a treat (even in Chrome)!
>
> [Turns to hide blushes]
>
> Changing the subject quickly: Would you happen to have an update on
> the availability of boards/kits for the ingenious LNB project that you
> demonstrated at the S Yorks Round Table event?
>
> 73 de Darren
> G7LWT
>
> 2009/8/6 bernie <bernie@earf.co.uk bernie@earf.co.uk>>
>
>
>
> I thought I had the same problem, but clicking on the far right hand
> miniscule arrow on each JPG listing then downloaded that
> particular picture.
>
> Bernie
>
>
>
> Andy Talbot wrote:
> >
> >
> > It doesn't even work with IE8 - just gives a list of JPGs but won't
> > allow viewing
> >
> > Andy
> > www.g4jnt.com <http://www.g4jnt.com>
> >
> > 2009/8/5 Dave Ackrill <dave.g0dja@tiscali.co.uk
> g0dja%40tiscali.co.uk>
> > g0dja%40tiscali.co.uk
> g0dja%2540tiscali.co.uk>>>:
>
> > >
> > >
> > > Peter Day wrote:
> > >>
> > >>
> > >> Here's the correct URL for public access. This should work OK (I
> > >> hope!)... You'll notice it changes the URL once you've
> clicked on it.
> > >>
> > >>
> > >> http://public.me.com/g3pho <http://public.me.com/g3pho>
> <http://public.me.com/g3pho <http://public.me.com/g3pho>>
>
> > >>
> > >
> > > Just to warn anyone not using Internet Explorer or Mozilla, it
> wont work
> > > with other browsers.
> > >
> > > Dave (G0DJA)
> > >
> > >
> >
> >
>
>
>


Re: Dish alligment...

f1ghb
 

 
And any project of beacon on 6 or 3 cm in EI ?
 
73s Eric
 

----- Original Message -----
Sent: Friday, August 07, 2009 5:16 PM
Subject: Re: [ukmicrowaves] Dish alligment...

 

Hi Tony
 
When I am out portable near home I have the luxury of a beacon GB3XGH which I use to align my dish. The bearing I use has a 360 degree scale selotaped to it. I use the radiodist program or the TK5EP Rainscatter program to calculate the heading from my location to the beacon.
 
In EI we do not have the luxury of a beacon, but I have used the plate on which the transverter is bolted onto to sight on local objects which I can calculate a heading to. This is the way I did it the other night when we were trying. It can sometimes be a challenge when you can't see because of fog or mist, then you have to estimate the direction of the road you are parked up on as the datum. Google Earth can be useful for this.
 
I am going to have to improve my pointing mechanism soon, as I am planning to start using a bigger dish - 80-90cm instead of the current 50cm.
 
regards
 
Bob
G8DTF


From: Tony Gallagher yahoo.com>
To: ukmicrowaves@yahoogroups.com
Sent: Thursday, 6 August, 2009 22:51:40
Subject: [ukmicrowaves] Dish alligment...

 

Hi,
I hope this isnt a silly question, but how are you all positioning your dishes? I have a marine compass with a sight so I know exactly where I need to point the dish on the horizon.
The problem is, I'm finding it hard to gauage what the dish is pointing to. I'm sure I'm accurate within 20degrees or so.
Has anyone come up with any clever way of alligning the dish more accurately?

Thanks everyone

Tony
EI4GHB



Re: Dish alligment...

Dave Ackrill <dave.g0dja@...>
 

The next problem, after you have pointed the dish, is how do you keep it pointing in the right direction in anything from a breeze to a howling gale? I'm already coming to the conclusion that I need some serious engineering construction to hold up the 83x73 offset fed dish.

So far, I've tried a pole with guys, and a large Christmas Tree base (not one of those fancy metal ones, this is a large plastic one with three screws with metal plates on) to give it something to rest upon.

The guys get in the way when you want to move the dish through more than a few degrees, and the base requires undoing and doing up each time you move the dish as well. Plus, keeping the rope guys taught can be tricky...

I am also coming to the conclusion that I need a longer cable between the feed horn and the transverter box. Mounting it on the boom from the dish just makes the whole thing even more unbalanced, in my experience so far.

I have wondered if the mast system sold with the portable G-Whip would be strong enough? Anyone seen one 'in-the-flesh' and can comment on whether it might be suitable for the job?

Thanks - Dave (G0DJA)