A cheap microwave transceiver?
Jonathan M Hill
I am a member of the ham radio club at Worcester Polytechnic Institute
in Massachusetts. Sorry, I am not offering a transceiver, actually
I am looking for information regarding a transceiver.
Recently I heard of a fellow who was building low power
microwave transceivers by using parts from old radar detectors.
A local ham radio clubs had a speaker who presented one of the
transceivers he had build. I'm not sure but I believe that the
transceiver operated in the 10 GHz band, with extremely low power.
The story goes that, for a few bucks you buy an old radar detecter, then
gut the detector for parts to make your transceiver. I guess all radar
detectors incorporate a gunn-plexer. With some kind of modification the
gunn-plexer will transmit, as well as down convert received signals.
Beleive it or not, the fellow who presented his transceiver used a
Ra*io Sh*ck portable radio as the IF demodulator.
We are looking for a simple, low cost project so that a number of people
can each build their own. The idea of using parts from a radar detecter
appears to have sparked our imagination. At this point, as far as microwaves
are concerned, most of our club members are ``newbies'' but think that such
a project would be a fun way to get our ``feet wet'', so to speak. Who knows,
this could lead us to bigger and better things....
So in summary, I'd like to ask if there is anyone out there who has
constructed such a transceiver from radar detector parts? Does anyone have
information that you think might be useful?
Jonathan Hill/N1QOL
--------------------------------------------------------------------------------
WPI Ham Radio Club, W1YK since 1913.
--------------------------------------------------------------------------------
mor...@ipers1.e-technik.uni-stuttgart.de
Jonathan M Hill <jmh...@duck.WPI.EDU> wrote:
> We are looking for a simple, low cost project so that a number of people
>can each build their own.
Jonathan,
The gunnplexers you have in mind are a nice thing, ( I built one about 12
years ago), but there are a few catches, you want to be aware of:
This wide band FM communication was done many years ago, when
the components cost hundreds of $, and allowed direct sight
communication over 100+ miles, between hill tops. Then they were the only
way to be QRV on microwaves.
Now days everyone has turned to low noise narrow band systems,
which offer a vastly enhanced range, and the gunnplexers are not
really used anymore with the exception of fast data links.
So If you want to build a few of these TRX in a group, you are fine,
but do not expect to have many QSO-partners in the rest of the world.
Also, if you want more than a few miles range, you need good antennas, which
envolve quite a bit of metal work, and you also need waveguide and flanges.
BTW, some gunnplexers (side-by-side units) cannot be connected to a proper
antenna.
73, Moritz DL5UH
Joe Landis - Systems & Network Mgr
> Hello all;
> I am a member of the ham radio club at Worcester Polytechnic Institute
> in Massachusetts. Sorry, I am not offering a transceiver, actually
> I am looking for information regarding a transceiver.
>
> Recently I heard of a fellow who was building low power
> microwave transceivers by using parts from old radar detectors.
> A local ham radio clubs had a speaker who presented one of the
> transceivers he had build. I'm not sure but I believe that the
> transceiver operated in the 10 GHz band, with extremely low power.
>
> The story goes that, for a few bucks you buy an old radar detecter, then
> gut the detector for parts to make your transceiver. I guess all radar
> detectors incorporate a gunn-plexer. With some kind of modification the
> gunn-plexer will transmit, as well as down convert received signals.
> Beleive it or not, the fellow who presented his transceiver used a
> Ra*io Sh*ck portable radio as the IF demodulator.
>
> appears to have sparked our imagination. At this point, as far as microwaves
> are concerned, most of our club members are ``newbies'' but think that such
> a project would be a fun way to get our ``feet wet'', so to speak. Who knows,
> this could lead us to bigger and better things....
>
> So in summary, I'd like to ask if there is anyone out there who has
> constructed such a transceiver from radar detector parts? Does anyone have
> information that you think might be useful?
>
> Jonathan Hill/N1QOL
Hi, not sure about radar detectors, I guess you may be able to use them.
Another inexpensive way to get into 10Ghz is using surplus Alpha Microwave type
Gunn diode assys from commercial motion sensors and door opener systems. You
can usually find these at hamfests for $10 or so. You modulate the Gunn P/S to
generate wide band FM. They include a mixer diode, which you can couple to your
FM reciever as an IF. It's a good idea to shield the FM recvr, and use a
preamp of some sort. Without AFC, you'll need the fast tuning of a broadcast
reciever to find and track the signal. It will drift a lot! I have tried using
a 2M IF and it is tough.
You'll need to tune these down a bit - they're usually at about 10.525Ghz. They
can be course tuned by a screw protruding into the cavity, and fine tuned by
varying the Gunn diode voltage. Using a system like this at both ends, you can
run full duplex. But the transmit freqs need to be offset by the amount of the
IF. There have been many articles written up in the magazines over the years on
how to do this. In older versions of the ARRL handbook, there were some,
including a nice one by Glenn Elmore on a 2Mb/s 10Ghz data link. The new
handbook dropped these!?!? Also, the RSGB VHF/UHF manual has some good stuff.
There have been some good articles published in QEX lately by Paul Wade
- N1BWT(?) on uwave antennas. It's fairly easy to build up, say an 18dbi horn
for these using his info.
Oh and another note - these are not Gunnplexers. Gunnplexers contain an
additional varactor for a seperate tuning scheme. You run them with a
fixed regulated supply and tune using the varactor. With the Alpha's, you do
it all by modulating the power supply (LM317's work well).
Have fun!
Joe - AA3GN
--
Joe Landis - Systems and Network Manager - North American Drager - Telford, PA
lan...@nad.com
Paul Beltrani
>Hello all;
> I am a member of the ham radio club at Worcester Polytechnic Institute
>in Massachusetts. Sorry, I am not offering a transceiver, actually
>I am looking for information regarding a transceiver.
>
> So in summary, I'd like to ask if there is anyone out there who has
>constructed such a transceiver from radar detector parts? Does anyone have
>information that you think might be useful?
I'm not sure about used RADAR detectors, however there is a gentleman
in CT that sell Gunn oscilators for $25 a pair. Add a few junk box parts
and a cheap FM transistor radio and you can start playing with WBFM.
Those interested can e-mail me for more info.
Paul, AH6NU
belt...@aloha.com
Neil A. Gjere
>jmh...@duck.WPI.EDU (Jonathan M Hill) wrote:
>>Hello all;
>> I am a member of the ham radio club at Worcester Polytechnic Institute
>>in Massachusetts. Sorry, I am not offering a transceiver, actually
>>I am looking for information regarding a transceiver.
gentleman
>in CT that sell Gunn oscilators for $25 a pair.
>
I would be interested in this persons name and address etc...
73s
Neil N0PFZ
Simon Lewis
Depends what you want to do!
WBFM fine but pretty limited
Here in the UK we have some great transverter designs for 3cms by G3WDG
They use cheap gasfets and will give you 50mw out on 10 ghz - narrowband
They use a 2m transceiver as the if.
We have worked 1200km paths in EU with the design at 50mw - there is
also bigger amps for 300mw and !watt available - or you could drive a
Travelling Wave Tube Amplifier - I have one at 40 watts out. With a 4ft
dish you would be a BIG signal on the bands.
If you would like some more info then yell
73 From: Simon Lewis GM4PLM - Helensburgh - Strathclyde - Scotland
Packet: GM4PLM @ GB7SAN.#78.GBR.EU Email: sle...@pacsat.demon.co.uk
AMSAT - UK Member 4282 **** SUPPORT YOUR LOCAL AMSAT GROUP ****
Jack Mott
On 16 May 1995, peter freeman wrote:
> ...
> From memory, the details of some of these units is described in the
> Microwave Handbook, published by the RSGB. A detailed description
> was also published in DUBUS magazine in 1993 or 1994, over a couple
> of issues. Another useful source of information on microwaves in
> general which includes news on the new projects being developed under
> the auspices of the RSGB Microwave Committee is the Microwave
> Newsletter, also published by the RSGB.
Where can a list of RSGB publications be found? An internet source is
desirable.
Charles Mott
Simon Lewis
Published by the RSGB.
Speaking to Charlie Suckling G3WDG designer and organiser of the
microwave committee components service, he gave me the followig
information for non-uk parties wanting to build the transverters:
Banking arrangements have been made to accept personal cheques drawn in
US dollars, the exchange rate $1.5 to each UK pound. PLus
a banking fee of 10 dollars per order.
He is quite happy to send information out
about the designs and he can be
reached by email at
charles_suckling @ mcimail.com
Im also willing to help in
anyway I can by supplying components and hard to get items if required.
If anyone requires anymore info then please mail charlie or myself as
required.
peter freeman
>Simon Lewis <sle...@pacsat.demon.co.uk> writes:
>> ...
>> Here in the UK we have some great transverter designs for 3cms by G3WDG
>> They use cheap gasfets and will give you 50mw out on 10 ghz - narrowband
>> They use a 2m transceiver as the if.
>Are these written up somewhere? I'd like to take a look at these
>designs.
From memory, the details of some of these units is described in the
Microwave Handbook, published by the RSGB. A detailed description
was also published in DUBUS magazine in 1993 or 1994, over a couple
of issues. Another useful source of information on microwaves in
general which includes news on the new projects being developed under
the auspices of the RSGB Microwave Committee is the Microwave
Newsletter, also published by the RSGB.
Peter Freeman
peter freeman
>On 16 May 1995, peter freeman wrote:
>> ...
>> From memory, the details of some of these units is described in the
>> Microwave Handbook, published by the RSGB. A detailed description
>> was also published in DUBUS magazine in 1993 or 1994, over a couple
>> of issues. Another useful source of information on microwaves in
>> general which includes news on the new projects being developed under
>> the auspices of the RSGB Microwave Committee is the Microwave
>> Newsletter, also published by the RSGB.
>Where can a list of RSGB publications be found? An internet source is
>desirable.
>Charles Mott
The Microwave Handbook is listed in the ARRL Publications Catalogue
in the VHF/UHF/Microwave section. I am not currently aware of an
on-line source of data. I believe that the RSGB is NOT yet on the
Net. Good luck in finding the information.
Peter Freeman
VK3KAI
Gerhard Hoffmann
Peter Monta <pmo...@pmonta.qualcomm.com> wrote:
>Simon Lewis <sle...@pacsat.demon.co.uk> writes:
>> Here in the UK we have some great transverter designs for 3cms by G3WDG
>> They use cheap gasfets and will give you 50mw out on 10 ghz - narrowband
>> They use a 2m transceiver as the if.
>
>Are these written up somewhere? I'd like to take a look at these
>designs.
DUBUS
1/91: Michael Kuhne, DB6NT & Juergen Dahms, DC0DA
A Simple 10 GHz Transverter
( single board design, w/o oscillator )
3/93, 4/93, 1/94:
C. Suckling G3WDG & P. Suckling G4KGC & S. Jewell G4DDK
Modern 10 GHz Transverter System, Part 1/2/3
1/95: Philip Prinz, DL2AM:
10W GaAs-Fet Power on 10 GHz
Dubus is published quarterly by a team of hams and has tons
of interesting microwave stuff. Price is $25 per year.
It's bi-lingual English / German.
In the US, contact Russ Miller, N7ART
12041 S.W. Peninsula Drive, Crooked River Ranch, OR 97760
Gerhard
--
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# Gleditschstr. 79 # fax: +49 30 782 02 63 #
# D10823 Berlin # on the air: dk4xp #
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Simon Lewis
of The RSGB.
Get Building Guys!
MICROWAVE COMMITTEE COMPONENTS SERVICE PRICE LIST FEB 95
DESCRIPTION RSGB MEMBER PRICE NON MEMBER
1152 MHz LO PCB G4DDK001B 5.74 6.77
PHOTOCOPY OF G4DDK001B ARTICLE 1.00 1.18
TRIMMERS FOR G4DDK001B (5X5PF) 3.66 4.30
1152MHz AMP PCB G4DDK002 5.47 6.45
2-2.6GHz LO PCB G4DDK004 6.86 8.09
PHOTOCOPY OF G4DDK004 ARTICLE 1.00 1.18
TRIMMERS FOR G4DDK004 (8X5PF) 5.55 6.52
ATC DECOUPLING CAPS FOR G4DDK004 (2) 3.26 3.85
CRYSTAL HEATER 3.52 4.14
UHF SOURCE PCB 6.52 7.66
REGULATOR PCB (LOW VOLTAGE DROP FOR 12V) 2.38 2.80
BEACON KEYER PCB G4FRE008 7.14 8.42
144MHz 5mW SOURCE (G4JNT005) INC PIN DIODES 5.84 6.89
144MHz WIDEBAND NOISE AMP PCB G3WDG008 9.38 11.06
1.3GHz LOW POWER TRANSVERTER G4JNT004 68.66 81.02
5.7GHz DB6NT 8W PA PCB (DUBUS 3.92) 10.50 12.39
10GHz X4 MULTIPLIER/PA G3WDG001 29.83 35.20
10GHz RECEIVE CONVERTER G3WDG002 42.70 50.38
10GHz TRANSMIT CONVERTER G3WDG003 49.03 57.86
10GHz 1dB NF HEMT PREAMP G3WDG004 35.48 41.86
10GHz 300mW PA (60mW DRIVE) G3WDG006 58.93 69.53
10GHz 1W PA (200mW DRIVE) G3WDG007 131.68 155.38
10GHz DB6NT 4W PA PCB 2-STAGE (DUBUS 4.91) 10.50 12.39
10GHz DB6NT 4W PA PCB 1-STAGE (DUBUS 4.91) 10.50 12.39
12/24GHz DB6NT DOUBLER PCB (DUBUS 1-2.92) 7.00 8.26
24GHz DB6NT HEMT AMP PCB (DUBUS 4.93) 10.00 11.80
24GHz DB6NT PA PCB (DUBUS 4.93) 10.00 11.80
24GHz DB6NT HEPA PCB (DORSTEN 2.95) 11.00 12.98
24GHz DB6NT Mk2 TRANSV. PCB (DUBUS 1.93) 12.50 14.75
KIT FOR ABOVE (2 X BAT15 DIODES & 1pF CAP) 10.00 11.80
47GHz DB6NT MIXER PCB (DUBUS 1.94) 10.00 11.80
47GHz DB6NT IF PCB (DUBUS 1.94) 4.00 4.72
23/47GHz DB6NT DOUBLER PCB (DUBUS 4.93) 10.00 11.80
76GHz DB6NT MIXER X4 PCB (DUBUS 2.92) 10.00 11.80
76GHz DB6NT IF PCB (DUBUS 1.94) 4.00 4.72
76GHz DB6NT MIXER X2 PCB (DUBUS 1.94) 10.00 11.80
25.3/76GHz DB6NT TRIPLER PCB (DUBUS 1.94) 10.00 11.80
19/38GHZ DB6NT DOUBLER PCB (DUBUS 1.94) 12.50 14.75
145GHz DB6NT MIXER PCB (DUBUS 2.94) 10.00 11.80
241GHz DB6NT MIXER PCB (DUBUS 2.94) 10.00 11.80
HYBRID MKU55 (DUBUS 1.91) 9.50 11.21
WAVEGUIDE 16 TO SMA TRANSITION (NO FLANGE) 15.00 17.70
TRANSVERTER SWITCHING UNIT G4JNT001 24.88 29.36
2SK1844 HEMT (0.7dB NF/12GHz) 13.78 16.26
MGF1302 (use in place of "Black Dot" FET) 3.50 4.13
MGF1801 GaAsFET (250mW - 10GHz) 38.27 45.16
MAR1 MODAMP 2.46 2.90
MAR3 MODAMP 3.02 3.56
MAR6 MODAMP 2.92 3.44
MAV11 / MSA1104 MODAMP 4.75 5.57
UPB582C 2.6GHz PRESCALER (DIVIDE BY 4) 7.43 8.73
100OHM CHIP RESISTORS (10) 0.50 0.60
2.2 PF ATC CHIP CAP (GOOD TO 10GHZ) 1.32 1.58
4.7PF CHIP CAPACITORS (10) 1.00 1.18
10PF CHIP CAPACITORS (10) 1.00 1.18
22PF CHIP CAPACITOR (10) 1.00 1.18
470PF CHIP CAPACITOR (10) 1.00 1.18
10NF CHIP CAPACITOR (10) 1.00 1.18
100NF CHIP CAPACITOR (10) 1.00 1.18
CUCLAD 233 0.79MM PCB (TEFLON) 2X1 INCH 2.32 2.74*
LOSSY RUBBER (2X1 INCH PIECE) 1.50 1.77 *
WG20 WAVEGUIDE (PER FOOT) 10.46 12.34
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+-------------------------------------------------------------------------+
| 73 From: Simon Lewis GM4PLM - Helensburgh - Strathclyde - Scotland |
| Packet: GM4PLM @ GB7SAN.#78.GBR.EU Email: sle...@pacsat.demon.co.uk |
| AMSAT - UK Member 4282 **** SUPPORT YOUR LOCAL AMSAT GROUP **** |
+-------------------------------------------------------------------------+
Todd Gruener
got the dishes and I definitely have a fm radio. Thanks, TODD. KB7RBI
Peter Monta
Peter Monta pmo...@qualcomm.com
Qualcomm, Inc./Globalstar