5.76ghz transverter
5.76ghz transverter
Here are some photos of my transverter that I have been building. It uses one of the vk3dxk kits for the transverter and the local osc is a mini kits osc running at 592mhz then x3 to 1776mhz using the board supplied by vk3dxk. I have mounted all of this in a power amp module which I gutted and modified to give me an output of around 30dbm.
The power amp with the covers on.
The vk3dxk transverter.
The power amp and bias control. The mini kits osc and x3 board mounted down the bottom.
All that left to do if mount the output relay then I am finished. The only promble is the relay I have is 28v.
VK5TX
Ben
The power amp with the covers on.
The vk3dxk transverter.
The power amp and bias control. The mini kits osc and x3 board mounted down the bottom.
All that left to do if mount the output relay then I am finished. The only promble is the relay I have is 28v.
VK5TX
Ben
Last edited by VK5TX on Wed Dec 15, 2010 7:11 am, edited 1 time in total.
Re: 5.76ghz transverter
Hi Ben,
Nice job!
Triggering the relay only needs a 28V (or there abouts) pulse. Thereafter, 12V will hold it closed. There are simple circuits around employing an NE555 as a Voltage doubler to do just that. A quick Google should find it, but if you can't, let me know and I will find it for you. I use the same little circuit on my 28V relay on my 10GHz rig and it works great.
73 - Rob VK2GOM / G0MOH
Nice job!
Triggering the relay only needs a 28V (or there abouts) pulse. Thereafter, 12V will hold it closed. There are simple circuits around employing an NE555 as a Voltage doubler to do just that. A quick Google should find it, but if you can't, let me know and I will find it for you. I use the same little circuit on my 28V relay on my 10GHz rig and it works great.
73 - Rob VK2GOM / G0MOH
Re: 5.76ghz transverter
I built a 12v to 24v converter but it is to big. If the relay only needs a 24v pulse I can make the board smaller.
Last edited by VK5TX on Tue Dec 14, 2010 9:01 pm, edited 1 time in total.
Re: 5.76ghz transverter
I used the circuit contained in this article http://www.microwavers.org/files/10GHz/ ... _aug07.pdf for my 10GHz transverter to enable operation of the 28V relay from a 12V supply and it's very simple.
Re: 5.76ghz transverter
Hi
I just built this to test a theory and it works fine. The output is 22v with no load and drops to 16.5v with the relay activated. This is sufficient to hold the relay on.
73
Iain
VK5ZD
I just built this to test a theory and it works fine. The output is 22v with no load and drops to 16.5v with the relay activated. This is sufficient to hold the relay on.
73
Iain
VK5ZD
73
Iain Crawford - VK5ZD
Munno Para West, SA - PF95ih
Iain Crawford - VK5ZD
Munno Para West, SA - PF95ih
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Re: 5.76ghz transverter
This is what I use - it has about the lowest parts count possible.
R1 = 1K. C1 = 1000uF 25V. D1/2 = 1N4001. TR1 = BD139 or similar
Don't worry about the comment about V+. It's originally a relay speedup circuit. However, it quite happily runs 26V relays from 12V.
I've used this with 26V relays ranging from mini SMA to Transco Y (BIG!) and it hasn't missed a beat. With the Transco (which draws 0.23A per coil, and there are two coils!), I did a crude experiment to see how fast it would recharge by rapidly tapping two wires together. I couldn't get it to falter, even though it was probably switching at about 3-4 Hz - much faster than you'd ever need.
Regards,
Dave.
R1 = 1K. C1 = 1000uF 25V. D1/2 = 1N4001. TR1 = BD139 or similar
Don't worry about the comment about V+. It's originally a relay speedup circuit. However, it quite happily runs 26V relays from 12V.
I've used this with 26V relays ranging from mini SMA to Transco Y (BIG!) and it hasn't missed a beat. With the Transco (which draws 0.23A per coil, and there are two coils!), I did a crude experiment to see how fast it would recharge by rapidly tapping two wires together. I couldn't get it to falter, even though it was probably switching at about 3-4 Hz - much faster than you'd ever need.
Regards,
Dave.
Re: 5.76ghz transverter
like the circuit david , it is now archived for usage soon! thanks 73 mark VK2AMS
Re: 5.76ghz transverter
I made a sequencer using a 8 pin picaxe driving 3 outputs.
1. TX / RX change over and 8v for the TX / RX paths on the transverter boards.
2. Output relay.
3. A relay to turn the power on for the amp.
The amp I brought at a ham buy n sell for $20 and was used for 6Ghz TX only data link. So i removed some of the circuit boards and i am only using the power amp and the biasing board.
The amp was design to run 24 hours a day 7 days a week so the heat sink case is a bit of over kill for what I am using it for but I milled the case down so it is square and a little lighter. It was a big tight fitting every thing in as I didn't what to mount anything on the outside of the case but the change over relay I have is to big fit in so it will be mounted on the outside.
Ben
VK5TX
1. TX / RX change over and 8v for the TX / RX paths on the transverter boards.
2. Output relay.
3. A relay to turn the power on for the amp.
The amp I brought at a ham buy n sell for $20 and was used for 6Ghz TX only data link. So i removed some of the circuit boards and i am only using the power amp and the biasing board.
The amp was design to run 24 hours a day 7 days a week so the heat sink case is a bit of over kill for what I am using it for but I milled the case down so it is square and a little lighter. It was a big tight fitting every thing in as I didn't what to mount anything on the outside of the case but the change over relay I have is to big fit in so it will be mounted on the outside.
Ben
VK5TX
Re: 5.76ghz transverter
VK5TX wrote:I made a sequencer using a 8 pin picaxe driving 3 outputs.
1. TX / RX change over and 8v for the TX / RX paths on the transverter boards.
2. Output relay.
3. A relay to turn the power on for the amp.
Ben
VK5TX
ohh well done Ben,
wonder if you will publish that online or something so others may benefit the cct and the code
if you dont have a www site, I would be happy to put the info on my ham pages.
cheers
Dave
VK2TDN
Re: 5.76ghz transverter
Those old mosterous motorola power supplies have some and the micor bases have lots and lots of them.VK2CU wrote:A note to those building these(please-o-please some be in Sydney!),
With all the VK3XDK transverter activity lately, building these modules requires a lot of feedthrough capacitors to provide good shielding.
They seem to be a bit tricky to buy. Where to get them?
Justin VK2CU
Lou - VK3ALB
Being right doesn't excuse bad behaviour
Being right doesn't excuse bad behaviour
Re: 5.76ghz transverter
I have just completed some short range tests Ian VK5ZD and it appears I have a problem. When I TX the signal appears 20Khz lower that the RX frequency. The two paths share the same lo.
Ben
VK5TX
Ben
VK5TX
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Re: 5.76ghz transverter
Is the Minikits LO well regulated? Perhaps on Tx the supply voltage to it drops?
I guess you've checked the IF rig is OK.
I guess you've checked the IF rig is OK.
Re: 5.76ghz transverter
I'm building ones for 2.4, 5 and 10Ghz.VK2CU wrote:A note to those building these(please-o-please some be in Sydney!),
I've been very busy work wise but with a break over Christmas I hope to have the 5.8Ghz unit operational by January.
cheers
Tim
--
VK2XAX :: QF56if23 :: BMARC :: WIA :: AMSAT-VK
VK2XAX :: QF56if23 :: BMARC :: WIA :: AMSAT-VK
Re: 5.76ghz transverter
I think I have found the problem. When I TX a 2.8Mhz 200mV signal appears on the +ve supply rail and at the LO is around 40mV. I have put in 100nF caps on the power supplies to every board and the signal has dropped away.
Now I just need to do some more field tests to confirm every thing is good.
Ben
VK5TX
Now I just need to do some more field tests to confirm every thing is good.
Ben
VK5TX
Re: 5.76ghz transverter
After some test it seems that my cheap Chinese knock off hand held is no good but will do for now.
Here some photos of it all finished.
This is the output change over relay, the antenna connects to one of the outputs of the relay.
Power input, on switch and 432Mhz IF input.
This is the antenna I made to be used with the transverter. It has about 18dB gain.
Finally this is my cheap Chinese hand held radio I have been using.
Ben
VK5TX
Here some photos of it all finished.
This is the output change over relay, the antenna connects to one of the outputs of the relay.
Power input, on switch and 432Mhz IF input.
This is the antenna I made to be used with the transverter. It has about 18dB gain.
Finally this is my cheap Chinese hand held radio I have been using.
Ben
VK5TX
Re: 5.76ghz transverter
Hi Dave, Thank you for suggesting this simple solution, I knocked it up on some veroboard yesterday and it works well.VK3HZ wrote:This is what I use - it has about the lowest parts count possible.
R1 = 1K. C1 = 1000uF 25V. D1/2 = 1N4001. TR1 = BD139 or similar
Don't worry about the comment about V+. It's originally a relay speedup circuit. However, it quite happily runs 26V relays from 12V.
I've used this with 26V relays ranging from mini SMA to Transco Y (BIG!) and it hasn't missed a beat. With the Transco (which draws 0.23A per coil, and there are two coils!), I did a crude experiment to see how fast it would recharge by rapidly tapping two wires together. I couldn't get it to falter, even though it was probably switching at about 3-4 Hz - much faster than you'd ever need.
Regards,
Dave.
I am considering putting a reversed biased diode accross the relay coil to suppress the back EMF.
Have you tried this?
73 Gary VK2KYP
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Re: 5.76ghz transverter
Hi GaryVK2KYP wrote:I am considering putting a reversed biased diode across the relay coil to suppress the back EMF.
No need to - in fact, not recommended. D1, C1 & D2 provide back EMF protection, charging C1 at the same time. Putting a reverse diode across the relay would actually slow down the circuit.
Regards,
Dave.
Re: 5.76ghz transverter
Thanks Dave, The relay is a bit slow to release so I think I will reduce the C1 to 500 mfd.VK3HZ wrote:Hi GaryVK2KYP wrote:I am considering putting a reversed biased diode across the relay coil to suppress the back EMF.
No need to - in fact, not recommended. D1, C1 & D2 provide back EMF protection, charging C1 at the same time. Putting a reverse diode across the relay would actually slow down the circuit.
Regards,
Dave.
The excellant results that 2.4 GHz has been producing recently, everbody should trying to get on as many microwave bands as possible.
73 Gary VK2KYP
Re: 5.76ghz transverter
Justin,
I have quite a number of feed-thru's here. How many do you want?
Dan VK2GG
I have quite a number of feed-thru's here. How many do you want?
Dan VK2GG