Date   

Re: GB3MHK

David Wrigley <zen130696@...>
 

Hi Peter,

I like to keep the temp down to less than 50 deg C on a heat sink. I have previously used very large heat sinks, but recently I've been using fans - dual ones in case one fails. They can make a very small heat sink very effective.
The computer heat sinks are very effective and compact.

The other thing is to fit a remote temperature monitor LM35DZ - I have that on the beacon and it's very reassuring to check the temp of the PA and see that even in hot weather (?) it rarely gets above 40 deg C.

David G6GXK



Peter Day wrote:


SAM JEWELL wrote:


If Bob could find the PA after his move it might get used!
LOL!!!


I can well understand that. I'm very loath to leave mine on for more
than 3 minutes at a time and I've got a BIG heatsink on it! It was on
for 10 minutes last Sunmay at one time and I was very nervous:-)

I'd be interested to learn how they sink them in commercial applications.

73

Peter, G3PHO


GM4PLM

Conrad G0RUZ <conrad@...>
 

Simon can you contact me off the list please.

73

Conrad G0RUZ


Re: GB3MHK

Peter Day <microwaves@...>
 

SAM JEWELL wrote:
If Bob could find the PA after his move it might get used!
LOL!!!

Seriously, it will be used at some later stage. But, it is quite an engineering job to add such an amplifier to an outdoor unit in our beacon situation.

I can well understand that. I'm very loath to leave mine on for more than 3 minutes at a time and I've got a BIG heatsink on it! It was on for 10 minutes last Sunmay at one time and I was very nervous:-)

I'd be interested to learn how they sink them in commercial applications.

73

Peter, G3PHO


Re: 10ghz Gunnplexer setup help!

Peter Day <microwaves@...>
 

Tony Gallagher wrote:
Hi everyone,
Ive recently started experimenting with 10ghz and Im currently
building a 10ghz gunnplexer transceiver as a entry level project.
I need to locate a 1N23 mixer diode or similar to calibrate the
gunnplexer.
Hi Tony,

Glad to hear you are building the gunnplexer. You'll need two units of course if you want to work someone else as everything is ssb/cw these days :-) However two pals can have a lot of fun with the old wideband gear and it's a cheap and fun way to go ... are we allowed to have fun in microwaves? :-)

J. Birkett,
The Strait,
Lincoln, UK

sells very similar diodes to the IN23 series. They are not critical for the application you intend them for. I find an oscillator outputting in the 1GHz region gives very strong harmonics, as high as 24Ghz or more, when driving a mixer diode taken from a SAT TV LNB. The "design" for this is also on my website under Technical Articles,.

The higher the starter frequency the better as a low one will put out several signals within the 10GHz band itself. Another method of frequency checking, albeit a little more inaccurate but good enough for a gunn oscillator,is to find an old waveguide cavity wavemeter for the band. You see them at rallies sometimes. There may be someone reading this who has one gathering dust and is willing to let it go to someone who will use it.

Good luck and feel free to email me directly at any time.

Peter, G3PHO

www.g3pho.org.uk


Re: Which came first

Peter Day <microwaves@...>
 

Andy Talbot wrote:
This question came up in a discussion recently. Does anyone here know definitively?
"Which came first, Goretex waterproof clothing, or Goretex microwave cables ?"
If the former, how did they make the huge quantum leap from clothing to high-tech dielectric.

I would have thought the cable came first but I've been using Goretex based outdoor clothing for at least 20 years or so but the cable only in the last few years (it's so expensive!). Both the cable and the clothing are really good items :-)

Peter, G3PHO


Re: 10ghz Gunnplexer setup help!

David Wrigley <zen130696@...>
 

Hi Tony,

Your best bet is the mixer diode from an LNB

But whilst this will produce harmonics it won't tell you which one you have - unless you feed it thru a WG filter.
It should be possible to design a very broadband and easily constructed filter to enable harmonics in the region of 10 to 10.5 Ghz. 432MHz would give you a good harmonic on 10368. Measuring the distance between peaks or nulls with a rule will give you a clue as the the region of the freq.

I've just checked my old LNB's - they use a later IC in place of the old diode pair.


David G6GXK


Tony Gallagher wrote:


Hi everyone,
Ive recently started experimenting with 10ghz and Im currently
building a 10ghz gunnplexer transceiver as a entry level project.
I need to locate a 1N23 mixer diode or similar to calibrate the
gunnplexer.

.

73's

ei4ghb
tony


Re: GB3MHK

SAM JEWELL
 

If Bob could find the PA after his move it might get used!

Seriously, it will be used at some later stage. But, it is quite an engineering job to add such an amplifier to an outdoor unit in our beacon situation.

73 de Sam


Peter Day wrote:

SAM JEWELL wrote:
>
>
> Hi John,
> thanks for the report on hearing GB3MHK. That is a great relief as I'm
> having problems hearing it here! The present arrangement is temporary,
> as previously stated. The signal should be a bit stronger once the
> beacon outdoor unit goes outdoors on the balcony rail.

When do you plan to fit the 3 watt PA that was donated at Martlesham a
couple of years ago? That would give another 10dB over the present
system!

Peter, G3PHO



Re: Which came first

Arie Dogterom <pa0ez@...>
 

But I got my raincoat first
Arie
 

----- Original Message -----
Sent: Wednesday, July 04, 2007 6:36 PM
Subject: [ukmicrowaves] Re: Which came first


Cable came first

http://www.gore.com/en_xx/aboutus/

Murray

--- In ukmicrowaves@yahoogroups.com, "Andy Talbot" ...>
wrote:
>
> This question came up in a discussion recently. Does anyone here know
> definitively?
>
> "Which came first, Goretex waterproof clothing, or Goretex microwave
cables
> ?"
>
> If the former, how did they make the huge quantum leap from clothing
to
> high-tech dielectric.
>
>
> Andy G4JNT
>


Re: GB3MHK

Peter Day <microwaves@...>
 

SAM JEWELL wrote:
Hi John,
thanks for the report on hearing GB3MHK. That is a great relief as I'm having problems hearing it here! The present arrangement is temporary, as previously stated. The signal should be a bit stronger once the beacon outdoor unit goes outdoors on the balcony rail.
When do you plan to fit the 3 watt PA that was donated at Martlesham a couple of years ago? That would give another 10dB over the present system!

Peter, G3PHO


Re: Which came first

Murray Niman <mjniman@...>
 

Cable came first

http://www.gore.com/en_xx/aboutus/

Murray

--- In ukmicrowaves@yahoogroups.com, "Andy Talbot" <andy.g4jnt@...>
wrote:

This question came up in a discussion recently. Does anyone here know
definitively?

"Which came first, Goretex waterproof clothing, or Goretex microwave
cables
?"

If the former, how did they make the huge quantum leap from clothing
to
high-tech dielectric.


Andy G4JNT


Which came first

Andy Talbot <andy.g4jnt@...>
 


??wave gage??

kenneth ferguson <ken_ferguson@...>
 

how do you tell what frequency a gage is I some od bits and would like
to use them as im looking for short lengths for 10g a proposed dish
if i know I can use them it would help my costs.
ken


10ghz Gunnplexer setup help!

Tony Gallagher <tony_g_ireland@...>
 

Hi everyone,
Ive recently started experimenting with 10ghz and Im currently
building a 10ghz gunnplexer transceiver as a entry level project.
I need to locate a 1N23 mixer diode or similar to calibrate the
gunnplexer.

This is what I've found online, (its a quote from
http://www.g3pho.free-online.co.uk/microwaves/setup.htm )
I hope its ok to include it in this email.

It reads.......................

One of the simplest ways to do this is to use a 2m, 70cm or 23cm low
power signal to drive a microwave diode so that a whole string of
harmonics is produced, at least one falling into the 10GHz band. The
higher the original signal the more likely you are to find the
correct harmonic. Only a few hundred milliwatts drive (say up to
500mW) will be needed to produce a few, easily-heard microwatts on
10GHz. The easiest way to do this is to simply connect a microwave
mixer diode (eg a 1N23 or similar, or even a more modern type such
as one taken from a surplus X band Satellite LNB) across a BNC
socket. Solder it from the spiggot to the body of the connector.
Then feed 2m, 70cm etc in via a length of coax. Poke the diode end
of the assembly near to the mouth of the doppler module's waveguide
and coarse tune the module until you hear the signal. This is made
much easier if you switch on the TONE OSCILLATOR which is part of
the simple circuitry described in this article.



I need to locate a 1N23 or similar. Can anyone suggest a possible
source or name a few easily obtained ghz mixer diodes that will
produce harmonics and allow me to "find the 10ghz band".
Thanks in advance and sorry if this has been covered before.

73's

ei4ghb
tony


Re: GB3MHK

SAM JEWELL
 

Hi John,
thanks for the report on hearing GB3MHK. That is a great relief as I'm having problems hearing it here! The present arrangement is temporary, as previously stated. The signal should be a bit stronger once the beacon outdoor unit goes outdoors on the balcony rail. That won't be for a while as the top section of the tower is due to be re-painted sometime this summer.
Also, the beacon outdoor unit needs to have some attention as I now believe that the very old DB6NT MKU LO 12 unit may be the source of the mode jumping of about 1kHz. This is not the usual jitter problem as the 125.254MHz source was settling down nicely here, whilst on test. The use of a new and longer cable possibly provoked the problem.

I will probably obtain a new MKU LO 12 from Michael later this month.
The beacon output is currently 250mW to a 10dBi gain antenna. This is screened back into the tower, but you are pretty much on the main lobe out of the tower window. So, EIRP ~2.5W
Unfortunately (!) the beacon will be re-aligned back to .830MHz at some stage. Probably when the MKU is changed.

All of this is subject to G3XDY's assistance, as the official beacon keeper. John has the last word!

G3XDY and G4FSG will no longer be able to claim the beacon as 'Simon and Sam's private 24GHz beacon'!

Noted on hearing the beacon when the 10G signals were not S9+.

Thanks for the report.

73 de Sam






g4eat wrote:

Sam,

You will be pleased to know I heard MHK 53s last night after the rain
had left Wimbledon and swept over Ipswich.

The usual rule of "sigs need to be at least S9 on 10G" did not apply
as MHX was S6rs. I suspect this is more of a function of the antenna
patterns in my direction and lower ERP on 10G towards me.

On a selfish note, I am quite happy with the beacon being on 822 as
my IF at 1296MHz already has a strong MHL component at 830 !!

Sam, what's your estimate of the MHK ERP in my direction?

Well done on building this fine beacon...it will help the ever
increasing activity on 24G.

73's John G4EAT

--- In ukmicrowaves@yahoogroups.com, SAM JEWELL wrote:
>
> The Martlesham Radio Society (G4MRS) are pleased to announce that
GB3MHK, on 24048.830MHz, is now QRV from the Martlesham radio tower.
It is located in a temporary location inside the tower and this is
restricting coverage to due west with a possible 3dB beam width of
240 - 310degrees.
> Re-painting of the tower will be completed later this summer. Once
it is we will move the beacon outdoor unit to its proper outside
location.
>
> The oscillator source is currently giving some concern. It was
working very well when it left here, but listening to it now, the
frequency is showing some random mode jumping. Currently, the beacon
is about 5kHz low in frequency. This will be corrected, probably next
week.
>
> regards
>
> Sam, G4DDK
> for G4MRS
>



WTB: Microwave Modules MMT-432 or similar

Christophe Huygens <christophe.huygens@...>
 

Hi all,

to connect my 24GHz equipment to the SDR I am urgently looking
for a simple 432/28 transverter or converter. Anything will
basically do.

Thanks es 73,
Xtof on4iy


Re: GB3MHK

g4eat <g4eat@...>
 

Sam,

You will be pleased to know I heard MHK 53s last night after the rain
had left Wimbledon and swept over Ipswich.

The usual rule of "sigs need to be at least S9 on 10G" did not apply
as MHX was S6rs. I suspect this is more of a function of the antenna
patterns in my direction and lower ERP on 10G towards me.

On a selfish note, I am quite happy with the beacon being on 822 as
my IF at 1296MHz already has a strong MHL component at 830 !!

Sam, what's your estimate of the MHK ERP in my direction?

Well done on building this fine beacon...it will help the ever
increasing activity on 24G.

73's John G4EAT


--- In ukmicrowaves@yahoogroups.com, SAM JEWELL <jewell@...> wrote:

The Martlesham Radio Society (G4MRS) are pleased to announce that
GB3MHK, on 24048.830MHz, is now QRV from the Martlesham radio tower.
It is located in a temporary location inside the tower and this is
restricting coverage to due west with a possible 3dB beam width of
240 - 310degrees.
Re-painting of the tower will be completed later this summer. Once
it is we will move the beacon outdoor unit to its proper outside
location.

The oscillator source is currently giving some concern. It was
working very well when it left here, but listening to it now, the
frequency is showing some random mode jumping. Currently, the beacon
is about 5kHz low in frequency. This will be corrected, probably next
week.

regards

Sam, G4DDK
for G4MRS


Bellhill beacons - back

pjm <pauljmarsh@...>
 

It was tremendously wide and very strong just prior to going off.
Lets hope no damage done
Morning all,

The power to bell hill returned at approximatly 23:30:57 last night,
having gone off at 18:15:12.

The 2.3GHz beacon is loud and clear this morning on 2320.890.

regards,

Paul M0EYT


G8ACE

Conrad G0RUZ <conrad@...>
 

John sorry for using this forum but I lost your email address some how. Anyway I need a 2 OCXOs and 2 reflock board kits, what is the current status please.
 
73

Conrad G0RUZ


Re: Lower microwave bands activity days

John Quarmby
 

Hi Dave

The RSGB runs a cumulative event through the year to partially coincide with
the 3rd Tuesday Scandinavian Activity Contests, the difference is the timing
which is 20:00 - 22:30 local for the RSGB event and 18:00-22:00 for the
continentals. The RSGB event also includes 13cm, whereas the 13cm and up NAC
is on the 4th Tuesday (The RSGB run a 50MHz event on that day).

See you on the 17th I hope!

73

John G3XDY

----- Original Message -----
From: <dave.g0dja@tiscali.co.uk>
To: <ukmicrowaves@yahoogroups.com>
Sent: Monday, July 02, 2007 11:38 AM
Subject: [ukmicrowaves] Lower microwave bands activity days


If I read the calendars correctly,the next UKuW contest which includes
1.3GHz is the 1st Cumulative contest (all microwave bands) starting on
the 4th November and the next RSGB one is the 1.3 and 2.3GHz Trophy
contests on the 6th October.

That being the case, are people likely to be more active on the lower
bands on the third Tuesday in each month during the Summer, I wonder?

By my calculations, these will take place on the following dates.

17th July
21st August
18th September

Dave (G0DJA)



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15:35


Re: Bellhill beacons 3/6cm

Ralph
 

Thanks Chris
Hope nothing serious
73
Ralph

----- Original Message -----
From: "C T" <eightgoes@yahoo.co.uk>
To: <ukmicrowaves@yahoogroups.com>
Sent: Tuesday, July 03, 2007 6:44 PM
Subject: Re: [ukmicrowaves] Bellhill beacons 3/6cm


3cms not audible here and telemetry showing odd readout ...a lot of storm activity today so its
possible there has been a hit.

73 de Chris G8BKE

Web Site:-
http://www.qsl.net/g8bke/index.html



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