Date   

IQ Upconverter chips

Andy Talbot <andy.g4jnt@...>
 

I have an order with Analog Devices for 25 AD8346ARU .chips. These
devices are 800MHz to 2.4GHz I/Q upconverters, featuring an internal
quadrature network accurate to 1 degree, and will work with the G3PLX
SDR transmitter software to form a direct conversion transmitter
source covering the 1.3 and 2.3GHz bands.

Data can be found at :
http://www.analog.com/en/prod/0%2C2877%2CAD8346%2C00.html
and
http://www.analog.com/UploadedFiles/Data_Sheets/AD8346.pdf

The chips are in a 16 pin TSSOP package with 0.65mm pin spacing, so
shouldn't be a headache to use even in a dead-bug sytle breadbaord
configuration.

LO drive required is <0dBm, gain is cheap and easy with ERA or GALI
modamps and no image filtering is needed, unlike a transverter from
144MHz drive, so a transmitter source ought to be a doddle.

Without knowing if / what any import duty will be, its impossible to
say precisely what the cost will end up at. The raw price from AD was
$4.85 each, so we're probably looking at somewhere in the region of
£3 each, ultimately. Delivery won't be until the second week in
October.

Hopefully they will have arrived by Martlesham time...

Andy G4JNT
www.scrbg.org/g4jnt


Updated SDR Tx Software

Andy Talbot <andy.g4jnt@...>
 

As promised last week, the updated Beta 2 version of G3PLX's SDR
Transmitter software is now available.

http://www.scrbg.org/g4jnt/SDRTransmitters.htm

The SSB speech clipper now works properly (based on a quick test with
the reference upconverter, it appears to work very well). Some other
minor bugs have been cleaned up.

Andy G4JNT
www.scrbg.org/g4jnt


Propagation Map

g4eat <g4eat@...>
 

As luck would have it, for those who went to Weinheim this weekend,
there was some VHF/UHF+ propagation this weekend.

A German op pointed out a useful propagation site:
http://www.mountainlake.k12.mn.us/ham/aprs/path.cgi?map=eu

It certainly proved accurate this morning. It showed a (red) ducting
path over 750km from HB9 towards EI.

Sure enough Arnold HB9AMH/P was strong on 3cms with 60dB to spare!!
Strong in JO01 but nil in IO91 which backed up the map that suggested
a tight duct path at that time.
Later propagation to the east with OK's on 2m and 70cms were also
worked along with OE on 23cms. The map did not show any direct
ducting to the east only local enhancements but I guess the mountain
top ops are usually strong.

The propagation data is based on VHF mainly 2m APRS data but it seems
a useful guide as to what may also follow on the higher microwave
bands.

73's

John G4EAT


Re: dish building

John Randall <m0els@...>
 

Chris, Its easier to purchase a kit from a place called rf hamdesigns
 
73
John

mm0kos wrote:
Hi All

Has anyone here tried to build ther own dish from fibreglass, i have
all the data to build the dish but dont want to build it from mesh as
it will probably be used /p at times and be thrown about a bit,
storage is a problem and with metal in the weather conditions in
Scotland.
im planning on a 4m dish first then maybe a 6m dish if all goes ok
and will either be an 8 or 4 petal dish, im thinking of using
fibreglass rod (4 or 6mm) to strengthen from the back with 4 alloy
15mm square sections to support the septum (or less if i use a patch
feed) and help keep the shape of the dish from the back. and a piece
of 10mm ally plate that all the 15mm box sections will bolt or have
some way of being inserted on to it
For the mould im using an insulating type foam board that can be
roughed down with a wire brush then sanded to a finer finish.
I have a dish stand suitable for the project that i hope to build
into a small trailer that will keep all the parts together when
dissasembled for transporting
Has anyone any other ideas how i could strenthen or ideas they have
used on their own project or anything they feel they could chip in for
advice

Thanks Chris MM0KOS




Yahoo! Answers - Get better answers from someone who knows. Try it now.


Re: dish building

Mike Willis <m.j.willis@...>
 

A 6m dish portable! In Scotland! Please no.

I would look around for a surplus one, dishes of that size are generally far too big for most amateurs and tend to be available for the price of taking them away. Building one from fibreglass is a major undertaking because of the wind loading. You could cover a mesh dish with fibreglass. Good luck.

Mike

mm0kos wrote:


Hi All

Has anyone here tried to build ther own dish from fibreglass, i have
all the data to build the dish but dont want to build it from mesh as
it will probably be used /p at times and be thrown about a bit,
storage is a problem and with metal in the weather conditions in
Scotland.
im planning on a 4m dish first then maybe a 6m dish if all goes ok
and will either be an 8 or 4 petal dish, im thinking of using
fibreglass rod (4 or 6mm) to strengthen from the back with 4 alloy
15mm square sections to support the septum (or less if i use a patch
feed) and help keep the shape of the dish from the back. and a piece
of 10mm ally plate that all the 15mm box sections will bolt or have
some way of being inserted on to it
For the mould im using an insulating type foam board that can be
roughed down with a wire brush then sanded to a finer finish.
I have a dish stand suitable for the project that i hope to build
into a small trailer that will keep all the parts together when
dissasembled for transporting
Has anyone any other ideas how i could strenthen or ideas they have
used on their own project or anything they feel they could chip in for
advice

Thanks Chris MM0KOS



dish building

Chris Ruddy MM0KOS
 

Hi All

Has anyone here tried to build ther own dish from fibreglass, i have
all the data to build the dish but dont want to build it from mesh as
it will probably be used /p at times and be thrown about a bit,
storage is a problem and with metal in the weather conditions in
Scotland.
im planning on a 4m dish first then maybe a 6m dish if all goes ok
and will either be an 8 or 4 petal dish, im thinking of using
fibreglass rod (4 or 6mm) to strengthen from the back with 4 alloy
15mm square sections to support the septum (or less if i use a patch
feed) and help keep the shape of the dish from the back. and a piece
of 10mm ally plate that all the 15mm box sections will bolt or have
some way of being inserted on to it
For the mould im using an insulating type foam board that can be
roughed down with a wire brush then sanded to a finer finish.
I have a dish stand suitable for the project that i hope to build
into a small trailer that will keep all the parts together when
dissasembled for transporting
Has anyone any other ideas how i could strenthen or ideas they have
used on their own project or anything they feel they could chip in for
advice

Thanks Chris MM0KOS


Re: 60watt amp

ken ferguson <ken_ferguson@...>
 

Ian sorry for delay just to say thank you for link and will have my amp soon.

ken




========================================
Message Received: Jul 29 2007, 11:49 PM
From: "Russ Stewart"
To: ukmicrowaves@...
Cc:
Subject: [ukmicrowaves] Re: 60watt amp

Ian Lamb wrote:
> Ken,
>
> Try www.dg0ve.de <http://www.dg0ve.de> - or www.google.com
> <http://www.google.com>
>
> 73 .. Ian
>
> ----------------------------------------------------------
> *From:* ukmicrowaves@yahoogroups.com on behalf of kenneth ferguson
> *Sent:* Sun 29/07/2007 22:06
> *To:* ukmicrowaves@yahoogroups.com
> *Subject:* [ukmicrowaves] 60watt amp
>
> Hello all I am in need of a 60 watt solid state amp for 23cms for a
> project can anyone here help please.regards
> ken
>
>
Not 60W but 45W@ 28V. Contact g3wdg, he does one; needs ~1.5W drive.
Thats what I currently use at masthed and I have 45W at the antenna feed
using a 30v supply.

regards de Russ ... g4pbp


test only from Gary VK2KYP

Gary <gbeech@...>
 


Re: Personal Beacon shutdown

gm0uhc <gm0uhc@...>
 

Martin . . .

I second what Chris says regards GPS locking. For some time I viewed
it as a 'black art' but it is nowhere near as intimidating as it
sounds. Also, I would have to agree to some extent with Chris's hint
that the quality of crystals these days isn't what they are cut
(pardon the pun) out to be. I have a crystal cut for 40 deg.
operation that is somewhat 'unruly, but my 'cupido' PLL board soon
keeps it in check!! I'd go for GPS locking, you won't regret it!

73,
Ian, GM0UHC

--- In ukmicrowaves@yahoogroups.com, Chris Bartram <yahoo@...> wrote:

Martin,

Personally, I'd bite the bullet and lock the beacon to GPS.

There are a number of reasons for this.

Firstly, GPS receivers are relatively cheap, even those intended
for
timing/frequency stabilisation applications are starting to
approach the
price of a decent custom crystal. It's now quite usual to find a
10MHz output
on 'timing' GPS receivers. There are a number of reliable designs
from eg.
CT1DMK and G4JNT which can be used to lock an existing crystal
oscillator to
a stable source.

Secondly, having recently had some very relevant professional
experience -
which I can't talk about in detail - I've come to the conclusion
that the
performance of custom crystals from most suppliers is getting worse
and worse
as the demand for them decreases.

Thirdly, operating even a good 20degree C crystal at an elevated
temperature
is not necessarily a Good Idea. It can work, but, crystals 'cut'
for
operation at room temperature sit on an inflexion of their
temperature/frequency characteristic, and so change frequency
relatively
little with temperature over a few degrees. Trying to operate the
crystal at
an elevated temperature will place it on a slope, and it becomes
much more
difficult to stabilise the frequency. Crystals cut for operation at
elevated
temperatures are available, but even from 'professional' suppliers,
they are
_much_ more susceptible to rapid aging effects than a room
temperature
crystal.

If you really don't want to go to the trouble of locking the
oscillator, one
technique which used to be used very successfully by a number of
people, but
which seems to have been forgotten, was to bury crystal oscillators
a metre
or so below the surface. At that depth the annual change in
temperature is a
degree or so, and discounting aging effects, oscillators will drift
very
little indeed...

Vy 73

Chris
GW4DGU


Re: Personal Beacon shutdown

Mike Willis <m.j.willis@...>
 

I would buy the GPS receiver before digging a 1m deep hole through chalk, clay or rock! Besides, if the frequency is off more than a Hz or two some people start moaning.

The ReflockII is reasonably cheap and is so far working well in the 250MHz reference supplying the GB3RAL VHF beacons. It is easy to set up once you remember where you left the instructions and the phase noise and note appear to be OK. I can not detect any warbling of the note at 250MHz. The Reflock will lock a VCXO of up to 125MHz directly, without needing a divider, which should be high enough as a starting reference in a multiplication chain for microwave beacon source.

Mike



If you really don't want to go to the trouble of locking the oscillator, one
technique which used to be used very successfully by a number of people, but
which seems to have been forgotten, was to bury crystal oscillators a metre
or so below the surface. At that depth the annual change in temperature is a
degree or so, and discounting aging effects, oscillators will drift very
little indeed...

Vy 73

Chris
GW4DGU


Re: Personal Beacon shutdown

Chris Bartram <yahoo@...>
 

Martin,

Personally, I'd bite the bullet and lock the beacon to GPS.

There are a number of reasons for this.

Firstly, GPS receivers are relatively cheap, even those intended for
timing/frequency stabilisation applications are starting to approach the
price of a decent custom crystal. It's now quite usual to find a 10MHz output
on 'timing' GPS receivers. There are a number of reliable designs from eg.
CT1DMK and G4JNT which can be used to lock an existing crystal oscillator to
a stable source.

Secondly, having recently had some very relevant professional experience -
which I can't talk about in detail - I've come to the conclusion that the
performance of custom crystals from most suppliers is getting worse and worse
as the demand for them decreases.

Thirdly, operating even a good 20degree C crystal at an elevated temperature
is not necessarily a Good Idea. It can work, but, crystals 'cut' for
operation at room temperature sit on an inflexion of their
temperature/frequency characteristic, and so change frequency relatively
little with temperature over a few degrees. Trying to operate the crystal at
an elevated temperature will place it on a slope, and it becomes much more
difficult to stabilise the frequency. Crystals cut for operation at elevated
temperatures are available, but even from 'professional' suppliers, they are
_much_ more susceptible to rapid aging effects than a room temperature
crystal.

If you really don't want to go to the trouble of locking the oscillator, one
technique which used to be used very successfully by a number of people, but
which seems to have been forgotten, was to bury crystal oscillators a metre
or so below the surface. At that depth the annual change in temperature is a
degree or so, and discounting aging effects, oscillators will drift very
little indeed...

Vy 73

Chris
GW4DGU


Re: Personal Beacon shutdown

GM6VXB
 

Grant,
 
Internal temperature in the enclosure has been up to 40 C and maybe higher during summer (did we have one ?).
Today we have air temperature of 13 C but the box in the sun is up to 28 C, dropping back to 20 C
when the sun goes in. Drift is around 5KHz measured 'off air' with a ref locked counter.
The beacon is one of the DB6NT boxes which has a crystal heater fitted.
Power supply is stable. I have a fan fitted to try to equalize the box internal temperature.
I did think about moving the whole beacon to the other side of the mast which would screen it from
the sun most of the day, maybe do this next year, but will play around to see if I can cure some of the
drift in a more controlled environment.
 
Regards,
Martin, GM6VXB
 

----- Original Message -----
Sent: Friday, September 14, 2007 12:49 PM
Subject: Re: [ukmicrowaves] Personal Beacon shutdown

Martin

Any idea what the maximum internal temperature is?

Kuhne Electronic makes a 40 C heater which fits onto a standard HC-49
and similar crystal; it can be fitted without any serious electrical
modifications to the oscillator, and would be useful if the internal
temperature is less than about 40C. No need to heat the enclosure if
all you need to do is heat the crystal.

(One day I'll have a look at modifying this heater to work at maybe 45C
or even 50C, and give out a bit more heat as the current design has
limited capacity. Unless Michael beats me to it.)

regards

Grant
>
>
> As we are starting into the beginnings of winter up here, I will be
> taking down my personal beacon while doing other antenna work.
> Have had no reception reports so can only presume it is of no real use
> in it's present location, maybe just too far North.
>
> I will try to fix the thermal frequency drift which is causing the
> beacon to change frequency by up to 8KHz when the
> sun (rarely) shines. Not sure of a cure as it means heating the
> enclosure above ambient or modifying the crystal oscillator,
> or as a last resort play around with Ref Locking.
>
> Also will have to change the semi rigid feeder as it has gone very green
> due to the salty atmosphere here.
>
> Regards,
> Martin, GM6VXB, IO97aq87.


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Re: Personal Beacon shutdown

Grant Hodgson <grant@...>
 

Martin

Any idea what the maximum internal temperature is?

Kuhne Electronic makes a 40 C heater which fits onto a standard HC-49 and similar crystal; it can be fitted without any serious electrical modifications to the oscillator, and would be useful if the internal temperature is less than about 40C. No need to heat the enclosure if all you need to do is heat the crystal.

(One day I'll have a look at modifying this heater to work at maybe 45C or even 50C, and give out a bit more heat as the current design has limited capacity. Unless Michael beats me to it.)

regards

Grant

As we are starting into the beginnings of winter up here, I will be taking down my personal beacon while doing other antenna work.
Have had no reception reports so can only presume it is of no real use in it's present location, maybe just too far North. I will try to fix the thermal frequency drift which is causing the beacon to change frequency by up to 8KHz when the
sun (rarely) shines. Not sure of a cure as it means heating the enclosure above ambient or modifying the crystal oscillator,
or as a last resort play around with Ref Locking.
Also will have to change the semi rigid feeder as it has gone very green due to the salty atmosphere here.
Regards,
Martin, GM6VXB, IO97aq87.


Personal Beacon shutdown

GM6VXB
 

As we are starting into the beginnings of winter up here, I will be taking down my personal beacon while doing other antenna work.
Have had no reception reports so can only presume it is of no real use in it's present location, maybe just too far North. 
 
 I will try to fix the thermal frequency drift which is causing the beacon to change frequency by up to 8KHz when the
sun (rarely) shines. Not sure of a cure as it means heating the enclosure above ambient or modifying the crystal oscillator,
or as a last resort play around with Ref Locking.
 
Also will have to change the semi rigid feeder as it has gone very green due to the salty atmosphere here.
 
Regards,
Martin, GM6VXB, IO97aq87.


Re: Microwave Voice Repeater - 10GHz circulator wanted

GM6VXB
 

David,
 
Still searching. I know I have two that run on 10GHz but so far only found the 2.4GHz ones.
I am wondering if I have lent them to someone as I have not seen them for a few years.
 
Trouble with searching through the cupboards is all the other useful stuff I keep finding and then
getting side tracked playing with them, but at least the wife is happy, I have thrown a lot of bits
out which were not needed.
 
Anyway, will keep looking and when I find them will send one down.
 
Regards,
Martin, GM6VXB
 

----- Original Message -----
Sent: Tuesday, September 11, 2007 3:31 PM
Subject: Re: [ukmicrowaves] Microwave Voice Repeater - 10GHz circulator wanted

Hi Martin,
 
I should have mantiond it !
SMAs will be perfect.
 
Will catch up later..
 
Just stopped at the house on my way to the deep south, back for the weekend (I hope...).
 
 
Cheers, David
 
 
 
----- Original Message -----
Sent: Tuesday, September 11, 2007 10:24 AM
Subject: Re: [ukmicrowaves] Microwave Voice Repeater - 10GHz circulator wanted

David,
 
What type of circulator, SMA or WG.
Think I have a couple of SMA types in my cupboard, will check.
 
Martin, GM6VXB
----- Original Message -----
Sent: Tuesday, September 11, 2007 7:33 AM
Subject: [ukmicrowaves] Microwave Voice Repeater - 10GHz circulator wanted

Hi All,
 
I am looking for a source of 10GHz circulators (not isolators) to complete the combiner for the 10GHz repeater experiment, GB3TC.
 
We have most of the other items we need to constuct a MK1 version, but if you have any other bits you may think would be useful to us, please let me know.
A low noise LO, or HPA, mixers etc etc for the next or even current version !
 
 
The main purpose of the repeater is to encourage amateurs onto 10GHz.
Turns out there are a few 10GHz lurkers with old Gunn type gear around here.
Hopefully this will stimulate them into listening, improving their gear, and then onto better things !
Perhaps more of an interactive beacon than repeater....
 
 
 
I am rather preoccupied with a family matter just now, but will be able to chat more about this soon.
(I am going to be away most of the rest of this week).
 
 
Cheers, David GM6BIG
 


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23CM TRANSVERTER PACKED UP

John Randall <m0els@...>
 

Is there anyone who could look at my mmt 1296 transverter as it went sk
last night.I noticed a chirping note on the martlesham beacon, which
got worse, until it just stopped.Now I am unable to find a beacon at
all, although it does tx ok.

I can eith bring it to you or send it via post....Let me know the costs
involved.


Thanks

John


Martlesham 2007

Ian Lamb <ianlamb@...>
 

The UK Microwave Group (UKuG) is holding it's AGM on Sunday 11th
November 2007 at the Martlesham Microwave Roundtable meeting, the
AGM agenda will appear in the UKuG October 2007 Scatterpoint.

We are looking for enthusiastic volunteers to join our committee and help
shape the future of UKuG. This year Steve Davies G4KNZ is standing
down as UKuG Treasurer so we are interested to hear from anyone
numerate who would be willing to take on this UKuG officers position.

On behalf of Brian, G4NNS, the UKuG Committee and the UKuG
membership I would like to formally thank Steve for his dedication and
efforts during the last 5 years as Treasurer.

If you are interested in joining the committee, have any agenda or AOB
items for the AGM please contact the UKuG Secretary by email to
ianlamb@btconnect.com <mailto:ianlamb@btconnect.com> at least 21 days prior to the AGM
(ie: by 21st October 2007)

Thank you & looking forward to meeting as many of you as possible at
the Martlesham Round Table.

vy 73 .. Ian
G8KQW
UKuG Secretary


Crawley RT

Alan Melia
 

Hi all just a note and a bit of an ad for the Crawley Round Table. I will be
taking a stock of tin-plate boxes along and I also have a batch of kits for
G4DDKs "miracle" Very Low Noise Pre-amp for 23cms. Sam will not be present
as he is away over to Weinheim....I guess he was scared of being trampled in
the rush !!

See you there.

Cheers de Alan G3NYK
(the ex-one-arm bandit !!)


Re: GB3MAN 24GHz beacon

David Wrigley <zen130696@...>
 

Many thanks for the report - the first one to date. My transceiver isn't working at the moment so unable to check the freq - My 124.5 Xtal is refusing to operate on freq so I was using a sig gen locked to a freq std to provide the 124.5 LO for the transverter and that now has a fault on it - another thing to fix - and a crystal to order!
This beacon is not yet locked to GPS - still working on it. I will shift the freq back to 0.850 today.

Many thanks again - anyone out there who can give me a freq check on Thursday - please do so.

73 David.


Peter Day wrote:


I was very pleased to hear David Wrigley' 24GHz beacon, GB3MAN on
Sunday during the UKuG 24 and 47Ghz contest. It was not audible from
Merryton Low IO93AD74, where I set up during the morning, but in the
afternoon I drove over the "Cat and Fiddle" road that connects
Buxton and Maccesfield and found a layby, just north of Macclesfield
Forest, from where I was able to get the beacon at around S7.
According to my receiver the beacon frequency was 24048.865MHz +/-
1kHz or so.

I think Dave said the beacon was on .850 so this is puzzling. My
receiver was checked that morning against my station marker and
appeared to agree with G3ZME and their beacon frequency.

Many thanks for a very useful 24Ghz beacon for those of us who
operate /P from the Peak District hills.

Peter, G3PHO

__.


Re: Microwave Voice Repeater - 10GHz circulator wanted

David GM6BIG <aware@...>
 

Hi Martin,
 
I should have mantiond it !
SMAs will be perfect.
 
Will catch up later..
 
Just stopped at the house on my way to the deep south, back for the weekend (I hope...).
 
 
Cheers, David
 
 
 

----- Original Message -----
Sent: Tuesday, September 11, 2007 10:24 AM
Subject: Re: [ukmicrowaves] Microwave Voice Repeater - 10GHz circulator wanted

David,
 
What type of circulator, SMA or WG.
Think I have a couple of SMA types in my cupboard, will check.
 
Martin, GM6VXB
----- Original Message -----
Sent: Tuesday, September 11, 2007 7:33 AM
Subject: [ukmicrowaves] Microwave Voice Repeater - 10GHz circulator wanted

Hi All,
 
I am looking for a source of 10GHz circulators (not isolators) to complete the combiner for the 10GHz repeater experiment, GB3TC.
 
We have most of the other items we need to constuct a MK1 version, but if you have any other bits you may think would be useful to us, please let me know.
A low noise LO, or HPA, mixers etc etc for the next or even current version !
 
 
The main purpose of the repeater is to encourage amateurs onto 10GHz.
Turns out there are a few 10GHz lurkers with old Gunn type gear around here.
Hopefully this will stimulate them into listening, improving their gear, and then onto better things !
Perhaps more of an interactive beacon than repeater....
 
 
 
I am rather preoccupied with a family matter just now, but will be able to chat more about this soon.
(I am going to be away most of the rest of this week).
 
 
Cheers, David GM6BIG
 


No virus found in this incoming message.
Checked by AVG Free Edition.
Version: 7.5.485 / Virus Database: 269.13.14/999 - Release Date: 10/09/2007 17:43