Buying Mini-Circuits parts in the UK
Gary Morton
Mini-Circuits. At a recent radio rally I picked up a POS-900W VCO and
TUF-5SM mixer for a tenner (about $15). I intend to use them for
experimentation.
I've just finished construction of the (RSGB) simple spectrum analyser.
The linearity of the VCO leaves a lot to be desired, but may be
replacable with a Mini-Circuits VCO (the POS-300W, but is a bit
expensive at 20 quid).
I am aware of JAB who sell some of the MAR/MAV series amplifiers and the
SBL mixer. Does anyone know of any other suppliers in the UK, or even
better of anyone selling off old or surplus parts. What about Birkett?
regards...
--Gary
Ian White, G3SEK
As far as I'm aware, the only place in the UK where you can order the
full Mini-Circuits product line is from Mini-Circuits Europe on 01252
832600. Prices may not be good, though... expect about £1 = $1.
As you've found, other dealers may have a few selected items. The RSGB
Microwave Component Service sell mostly modamps, Hands Electronics sell
some parts and so do GH Engineering. You can find all of these by a web
search.
Forget about Birkett - he's a surplus dealer so his stock is whatever he
happens to have right now. If you want what he has, then his prices are
very good; but if you want something specific, you need to go to a
regular component supplier, and expect to pay more.
Pity about the 'Simple Spectrum Analyser'. The person who designed it
more than 10 years ago is desperately trying to make RSGB stop
re-re-re-publishing it, because he knows it's out of date. The W7ZOI
design is a much better homebrew project (search for his web site).
--
73 from Ian G3SEK 'In Practice' columnist for RadCom (RSGB)
Editor, 'The VHF/UHF DX Book'
http://www.ifwtech.co.uk/g3sek
c....@nospammam.blueyonder.co.uk
Call minicircuits in the UK, they havea UK base too, I've ordered from them no
problem.
Clive
Godric Goodrich
mini-circuits web site -
Distribution Center/Local Rep. Mini-Circuits Europe Dale House, Wharf Road
Frimley Green, Camberley, Surrey GU16 6LF, England Phone: 44 1252-832600
Fax: 44 1252-837010
postm...@uk.minicircuits.com
Regards
Gee
G4NLA
"Gary Morton" <ga...@alma.demon.co.uk> wrote in message
news:3D62C9A6...@alma.demon.co.uk...
Gary Morton
>
> Gary Morton wrote:
> >I have recently become aware of the usefulness of the parts supplied by
> >Mini-Circuits. At a recent radio rally I picked up a POS-900W VCO and
> >TUF-5SM mixer for a tenner (about $15). I intend to use them for
> >experimentation.
> >
> >I've just finished construction of the (RSGB) simple spectrum analyser.
> >The linearity of the VCO leaves a lot to be desired, but may be
> >replacable with a Mini-Circuits VCO (the POS-300W, but is a bit
> >expensive at 20 quid).
> >
> >I am aware of JAB who sell some of the MAR/MAV series amplifiers and the
> >SBL mixer. Does anyone know of any other suppliers in the UK, or even
> >better of anyone selling off old or surplus parts. What about Birkett?
> >
>
> As far as I'm aware, the only place in the UK where you can order the
> full Mini-Circuits product line is from Mini-Circuits Europe on 01252
> 832600. Prices may not be good, though... expect about £1 = $1.
Thanks. I gave them a call. Using the POS-200 as an example the
conversion rate was as you said to expect.
> As you've found, other dealers may have a few selected items. The RSGB
> Microwave Component Service sell mostly modamps, Hands Electronics sell
> some parts and so do GH Engineering. You can find all of these by a web
> search.
>
> Forget about Birkett - he's a surplus dealer so his stock is whatever he
> happens to have right now. If you want what he has, then his prices are
> very good; but if you want something specific, you need to go to a
> regular component supplier, and expect to pay more.
Sure, but you never know what might turn up. It's interesting that every
advertisement is different. I'm trying to collect a full set ;-).
> Pity about the 'Simple Spectrum Analyser'. The person who designed it
> more than 10 years ago is desperately trying to make RSGB stop
> re-re-re-publishing it, because he knows it's out of date. The W7ZOI
> design is a much better homebrew project (search for his web site).
I'm aware of this newer design, but from my point of view there are
several drawbacks
o more expensive since it uses Mini Circuits mixers and VCO's.
(although this will give big advantages)
o only works from 0 to 70MHz.
(I want to make a 6m transmitter so I am interested in seeing
the 2nd harmonic just over 100MHz which the RSGB design can just
about do)
o the filters look more difficult to build.
o need to order the PCBs from the USA.
Is there any change someone clever person in the RSGB might design a
newer version with components easily obtainable in the UK, perhaps with
a wider frequency range?
Tonight I built the sweep generator and checked the calibration.
Seems accurate from -20dBm to -55dBm.
Over -20dBm there appears to be overload.
My signal generator only goes as low as -55dBm.
> --
> 73 from Ian G3SEK 'In Practice' columnist for RadCom (RSGB)
> Editor, 'The VHF/UHF DX Book'
> http://www.ifwtech.co.uk/g3sek
thanks for replying...
--Gary
Ian White, G3SEK
>> Forget about Birkett - he's a surplus dealer so his stock is whatever he
>> happens to have right now. If you want what he has, then his prices are
>> very good; but if you want something specific, you need to go to a
>> regular component supplier, and expect to pay more.
>
>Sure, but you never know what might turn up.
My junk-box contains 40 years of things bought from surplus dealers
because they looked useful - but they hardly ever are. Occasionally you
get lucky, and drop on just the weird part you wanted... but it's
usually about ten years too late.
>> The W7ZOI
>> design is a much better homebrew project (search for his web site).
>
>I'm aware of this newer design, but from my point of view there are
>several drawbacks
> o more expensive since it uses Mini Circuits mixers and VCO's.
> (although this will give big advantages)
> o only works from 0 to 70MHz.
> (I want to make a 6m transmitter so I am interested in seeing
> the 2nd harmonic just over 100MHz which the RSGB design can just
>about do)
Or more likely, not quite do in the standard configuration - every MHz
above 90MHz is a struggle. However, since the VCO in the G4PMK design is
built from discrete parts, for a special job you can always tweak the
whole coverage upwards, say from 20-110MHz.
> o the filters look more difficult to build.
> o need to order the PCBs from the USA.
>
Ordering the PCBs from the USA is no big deal, these days.
The same applies to ordering Mini-Circuits parts, except that M-C USA
probably won't accept orders from a UK address - they'll insist that you
order from M-C UK. The answer is to find a friend who will order them
from a US address, and then send them to you as a private 'small
packet'. M-C may not like it, but it is totally legal.
The bonus is that for a reasonably small declared value (maybe up to
about £60/$100), UK Customs are much more likely to waive charging VAT
and import duty on a private parcel than one from a commercial company -
even when the green Customs label is the same. Occasionally you will get
hit, and then it feels horrible... but it's still probably less than
you'd have paid M-C UK.
Returning to technical issues... apart from the more limited frequency
coverage, the W7ZOI analyser design has one overwhelming advantage over
the G4PMK design - it works better!
Of the G4PMK design, you say:
> Over -20dBm there appears to be overload.
That is a serious problem when you're trying to measure harmonic levels.
The better the harmonic suppression in the TX, the more likely it is
that the measured harmonics will be generated in the front-end of the
analyser.
>Is there any change someone clever person in the RSGB might design a
>newer version with components easily obtainable in the UK, perhaps with
>a wider frequency range?
>
Sure - his name's Gary Morton!
Unlike the ARRL, the RSGB isn't big enough to have its own lab or
technical staff - but even in QST you'll notice that the vast majority
of designs and projects come from individual amateurs... like W7ZOI.
With RSGB it's even more so.
Quite seriously, I think that if you set about designing a "born in the
UK" HB spectrum analyser, you'd end up very close to duplicating what
W7ZOI has done. The better a designer you become, the more likely you
are to arrive at the same conclusions as W7ZOI about the optimum system
architecture. Likewise, you'd probably end up using Mini-Circuits,
because nobody else on the planet makes a comparable range of reasonably
low-cost components.
Technically they aren't the very best, but in most cases they're better
than anything you could build without extensive test equipment. You can
drop them in and know that at least those parts of your circuit perform
as specified.
Equally important, they are *available* - easily in the USA, and in the
UK they are probably still the least difficult option.
@rl.ac.uk Mike
to build it? IF so, great. Otherwise get a surplus HP for a few £100 or use
a commercial scanner.
For example, the ICOM PCR1000 wideband receiver can be used as a basic
spectrum analyser with the right software (from the web). You need to add a
front end switched attenuator, especially if you want to make amplitude
measurements and you will need to calibrate the amplitude response, but
otherwise that is it for a 100kHz-1.3 GHz synthesised analyser.
Gary Morton
Hi Mike,
I've been checking out Ebay for spectrum analysers and they go for
several hundred pounds. From second hand equipment suppliers they don't
appear to be had for under 1000 quid. My interest is really in the
building and learning as I'm new to RF.
regards...
--Gary