Transmitting with the Pluto
Transmitting with the Pluto
Hi folks, please can you help me.
I have been receiving DATV from QO-100 for a while now and would like to get on air with some transmit.
I have a Pluto that I would like to use but I understand that the output is at best 1/2mW and therefore I guess I will need some amplification.
I also am quite a way from the dish so will need to overcome the feeder loss (15m or so).
I am not familiar enough with microwave equipment to know the how to do this.
There a plenty of people showing how they have modified/built high power amps, but a) I never seem to find suitable ones to modify (I did buy one but I afterward found it was an uncommon type that noone knows how to modify, cost me a pretty penny too) and I don't know really what to look for or b) it requires building skills and processes I don't have or have the equipment to carry out.
Can anyone suggest some off the shelf units that I could chain together to get me on the air. I have seen some on ebay (1W at £15, 4W at £36 and 8W at £40) that I think I have seen people chain together to feed the coax.
And finally (no pun intended) I am going to need something with more than 8W output at the dish so what should I be looking for to modify and suggested sources.
I am sure there are other people in a similar situation and are similarly confused who would be grateful of the help.
Thanks for reading this to the end and thanks in advance for any assistance.
Regards
Terry
I have been receiving DATV from QO-100 for a while now and would like to get on air with some transmit.
I have a Pluto that I would like to use but I understand that the output is at best 1/2mW and therefore I guess I will need some amplification.
I also am quite a way from the dish so will need to overcome the feeder loss (15m or so).
I am not familiar enough with microwave equipment to know the how to do this.
There a plenty of people showing how they have modified/built high power amps, but a) I never seem to find suitable ones to modify (I did buy one but I afterward found it was an uncommon type that noone knows how to modify, cost me a pretty penny too) and I don't know really what to look for or b) it requires building skills and processes I don't have or have the equipment to carry out.
Can anyone suggest some off the shelf units that I could chain together to get me on the air. I have seen some on ebay (1W at £15, 4W at £36 and 8W at £40) that I think I have seen people chain together to feed the coax.
And finally (no pun intended) I am going to need something with more than 8W output at the dish so what should I be looking for to modify and suggested sources.
I am sure there are other people in a similar situation and are similarly confused who would be grateful of the help.
Thanks for reading this to the end and thanks in advance for any assistance.
Regards
Terry
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- Joined: Wed Jan 06, 2016 9:46 am
Re: Transmitting with the Pluto
Depending on what software you intend to drive your Pluto with, you could mount it at the dish with the data over CAT5. A lot cheaper than good coax. Theres a lot of possibilities....
Gareth G4XAT
Gareth G4XAT
Re: Transmitting with the Pluto
That's definitely a good idea, however, the low output is still a major issue, so I am still looking for suggestions for amplifiers.
Thanks
Terry
Thanks
Terry
Re: Transmitting with the Pluto
Hi Terry
The real challenge here is generating enough power in the PA.
I would suggest that the way to do this with the minimum expense is to:
Dave, G8GKQ
The real challenge here is generating enough power in the PA.
I would suggest that the way to do this with the minimum expense is to:
- Get the biggest dish that you can.
- Work out how close you can get the PA to the dish. Don't be constrained by buildings - I have my PA in a large waterproof plastic box right next to the dish and feed mains and low level RF to the box.
- Work out the feeder loss and, knowing the size of your dish, you can then work out the PA Power Output that you need.
- You then need to find a suitable PA. This is the hardest, most expensive part as very few are available.
- Only after purchasing the PA should you think about spending money on driver amplifiers.
- Put sufficient amplification with the PA so that you only need to feed it less than 10 mW
- Use cheap satellite coax to feed RF from the shack
- Use enough (cheaper) amplification in the shack to overcome the long feeder loss to the PA
Dave, G8GKQ
Re: Transmitting with the Pluto
Hi Terry,
Bert Modderman is building power amplifiers for 13cms. You'll be hard pressed to find anything surplus so worth a look, I believe he makes driver amps too. I have some of his kit and it's superb quality.
http://www.pe1rki.com/amplifiers.html
Steve
Bert Modderman is building power amplifiers for 13cms. You'll be hard pressed to find anything surplus so worth a look, I believe he makes driver amps too. I have some of his kit and it's superb quality.
http://www.pe1rki.com/amplifiers.html
Steve
Find me on D Star through GB7BP
Re: Transmitting with the Pluto
Thanks Dave, I was already aware of most of this, I already have a 1.1m dish and it is in the clear and I get a reasonable MER with most transmissions from Es'hail. I already have a suitable box ready to go on the back of the mount to house the power amp. This is not where I have the problem.
The question I am trying to get to the bottom of is where can I get amplifiers, what types are suitable without major surgury to modify them and without breaking the bank. Can you use WiFi amps as cable drivers etc. If I go looking for ex commercial high power amps on places like ebay, what should I look for?
I hope that explains things a little better.
Regards
Terry
The question I am trying to get to the bottom of is where can I get amplifiers, what types are suitable without major surgury to modify them and without breaking the bank. Can you use WiFi amps as cable drivers etc. If I go looking for ex commercial high power amps on places like ebay, what should I look for?
I hope that explains things a little better.
Regards
Terry
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- Posts: 1242
- Joined: Wed Jan 06, 2016 9:46 am
Re: Transmitting with the Pluto
This popped up elsewhere,
"10 watts for 40-60mW drive @28V. Search eBay for 10W+ RF POWER AMP MODULE "MHPA21010" 2110MHZ-2170MHZ MOTOROLA"
They apparently deliver 10W on 2400, prety handy, data on the www.
Gareth
"10 watts for 40-60mW drive @28V. Search eBay for 10W+ RF POWER AMP MODULE "MHPA21010" 2110MHZ-2170MHZ MOTOROLA"
They apparently deliver 10W on 2400, prety handy, data on the www.
Gareth
Re: Transmitting with the Pluto
The MHPA21010 looks interesting but its going to need pcbs and heatsinks, something I am not able to do unfortunately.
Thanks for the idea though.
Thanks for the idea though.
Re: Transmitting with the Pluto
Hi All
The MHPA 21010 looks good
Has anyone build this allready and checked performance ?
I got my hands on one... so any info would be appreciated
Tnx Jemp, ON7MA
The MHPA 21010 looks good
Has anyone build this allready and checked performance ?
I got my hands on one... so any info would be appreciated
Tnx Jemp, ON7MA
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- Posts: 1242
- Joined: Wed Jan 06, 2016 9:46 am
Re: Transmitting with the Pluto
Yes, I have built one, -3dB drive from Pluto gives me about 3 watts DVBS-2.
See my article on page 32 of the latest CQ-TV (273).
Gareth
See my article on page 32 of the latest CQ-TV (273).
Gareth