You are not going to ever need that amp just for the NB-Transponder
Most likely not, but still good to get it tested, and i do have a small 60cm offset for portable use.
You are not going to ever need that amp just for the NB-Transponder
Most likely not, but still good to get it tested, and i do have a small 60cm offset for portable use.
So just to finish this off, i forgot that our local ham radio club has a spectrum analyzer, so im getting the upconverter, and amplifier tested as a unit to see what to expect at the different input powers (1-3 Watt), and how much the DXpatrol mk4 delivers on the output, both with and without the amplifier.
It also turns out its not a 1.5m dish, but a 2m dish.
Could i be so lucky there is a mod for a opticum lrp-04h, it is using a nxp t1044.
If you point your dish exactly to QO-100 then it should be enough power. My very first signal over QO-100 was in CW with about 500 mW without amp from the upconverter . The result was a very weak but stable signal on Goonhilly WebSDR.
Hi Thomas.
Remember without the amp i will have a max of 200mW, and i am sure the dx patrol up converter will have to be pushed to the limit for that kind of output.
I got told that the DX Patrol often are making a dirty signal, so i will try and keep my drive as low as possible, it would be nice with a dedicated ptt instead of VOX.
I will try.
Ronni
With your 1.5m dish you do not need an amplifier. Try first without one, the transponder is very sensitive.
Hi Thomas.
Just took a quick look on your QRZ page, im a big fan of the two old Kenwoods for QO-100, i have a TS-711E here, but unfortunately its not working at the moment.
I will try without the amplifier first, but i doubt it will be enough for a SSB contact.
Kind regards
Ronni
Display MoreRonni,
with the 1.5m dish you will not need more than 500mW transmit power at the dish.
Kind regards
Matthias
Hi Matthias.
I will make sure to add some attenuators to my shopping list, what is the best option for limiting the output ? Attenuators between the output of the dx patrol upconverter to limit the drive to amplifier, or attenuation on the output of the amplifier before the feed ?
For limiting the output from the TS2000 my shopping list includes a 40db 50w attenuator - 100mW should be enough to trigger the vox on the upconverter.
Without the possibility to measure the output its a bit hard - plan was not to trigger LEILA.
Kind regards
Ronni
Display MoreI don't buy that. If that is true, you must convert a max. of 2.8W into heat to have 200mW output. Meaning the upconverter has negative conversion gain (in the range of ~ -10/12dB) . If you have measurement gear for 2.4GHz it is of great interest what really is going on.
Set your TS2000 to a good , strong audio , the audio you like to have when you talk on 2m or shortwave. Do not touch audio settings for the the following measurements. Set TS2000 to minimum available power with it's power potentiometer. Now insert a 20dB attenuator , this should result in 50mW output. Connect your upconverter and measure the output , while you adjust the power adj potentiometer on the dx-patrol board. If you don't get 200mW out, turn pwr adj to it's highest setting , insert about 15 or 13dB instead of 20dB, for ~200-250mW input to the upconverter. Repeat measurements. I'm sure you will reach the maximum output power with less than 250mW input.
Many dx-patrol users say , the vox circuit will not work properly with low input power, but most of them adjust output power of their radios by reducing mic gain and compression. Which i believe is the wrong way.
Regards,
Martin
P.S. : I may be totally wrong.
Hi Martin.
Sorry no gear for measuring the output, it is possible that 200mW is a bit of a stretch, but i dont need that much output anyway, had a fellow ham do some measuring on my amplifier, and it will produce 12 watt with a 100mW input, and close to 30 watt with the max of 250mW in, but that is not tested.
Am i wrong for thinking that with about 100mW of drive and a output of 12w , i will get 4-5 watts at the antenna, there will be some loss in cables, connectors and so on.
I did read a bit about the TS2000 having ALC overshoot issues, and even at 5 watt setting, it will produce 60 watts for a short time before adjusting down - so it needs quite a attenuator to make sure there is no damage to the up converter.
Kind regards
Ronni
It is always beter to attenuate the INPUT TO THE Upconverter on the radio side , not the output after the upconverter . This will result in a clean signal without nasty sidebands. You should check if that is enough signal strength. If not, you still can kick in the amp. You will need attenuation ahead of the amp, I'm sure.
73
I will need some attenuation before the upconverter, minimum output on my TS2000 is 5 watt - and the upconverter needs between 1 and 3 watt, output alone should be a max of 200mW, so i need the amplifier, i am counting on being able to turn down the output power directly on the DXpatrol mk4 upconverter using the pwr adj, and in doing that limit the output from the amplifier.
Display MoreHi Ronni,
a 1.5m PFD is a nice dish. Go for it. You will then also have a good basis for receiving and eventually transmitting DATV signals via QO-100.
I am using a 1.8m PFD (old Kathrein dish which I refurbished). My dish is quite deep (f/D=0.29) and therefore a POTY feed is fits well. I do not use a lens in front of the 10GHz waveguide, just leave it open.
Do you know what the f/D of your dish is?
Most PFD dishes are between 0.3 and 0.4 and a POTY feed will then still serve you well.
On my website http://www.dd1us.de you can find some information about my setup incl. the feed-holder I built.
If you do not find it plase send me an Email and I will give you more details.
I kindly disagree with Martin: if you setup a 1.5m dish you should try to get out the optimum of it. Otherwise it is a waste of
time and material ...
Kind regards
Matthias
Hi Matthias.
Thank you for the reply, i still need to go and pickup the dish, so not much information is known, except its 1.5m, and its made from steel, and its free, so that is always a plus.
I will take a look at your website, and see what i can find, it sounds like a poty will be the way to go - better start looking after one.
Kind regards
Ronni
Hi Martin.
Thank you for the pictures, looks like a nice setup, and very simple with that poty.
Looks like i should go hunting for one of those, guess i need to play with the power when the antenna is done, should be possible to turn down the output on the upconverter, my amplifier should deliver 12 watt at 100mW input.
Hi Thomas.
Already been there, but not much information regarding prime focus antennas.
Regards
Ronni
Hi Martin.
Thank you for the reply, my goal was around 4-5 watt into the antenna, i got a 12 watt amplifier for use with the DX patrol up converter.
I am however still very much in doubt if i should go for the prime focus, or just get a 80-90cm offset dish.
Do you have any pictures of your antenna setup ?
Regards
Ronni
I've got offered a 1.5m prime focus dish, no LNB - just the dish.
Been doing some searching, and can see a few people are using prime focus for QO-100, but most are using offset.
If i choose to use a prime focus, what would be the best option, a poty or helix, and what about the LNB ?
I was hoping for that i could use DX Patrol LNB, since i have the dx patrol down converter, and up converter already on hand, but i know there is some differences when it comes to the LNB between an offset and a prime focus dish.
Regards
Ronni
I wrote a Wiki for newcomers, it should give you a few ideas.
AA_introduction
Thank you, i will take a look.
Got an upconverter from DG0VE (Mix2g4-SSB-144), and a 20 Watt amplifier, so i just need the antenna.
Regards
Ronni
OZ2RNH
Hi, this Helix seems to have a nice matching network /phasing line. I wanted to try something like that, but didn't have time to do. Do you have the possibility to measure the SWR and resonance? What are the dimensions of this line from N-Connector to backplane?
73 Gerhard
Hi Gerhard.
Sorry, i dont got anything to measure the antenna with at the moment, but the distance from the N connector to the backplate is 43mm.
Regards
Ronni
OZ2RNH
Hello Ronni, Welcome
The helix looks nice but have to be LHCP as feeder at the dish (reversed polarisation). You can try without dish with CW. But later you need a LHCP feeder and dish I think.
73
Hi.
Thank you for the reply.
I had a feeling that antenna would be a bit undersized for SSB, guess it's time to start looking for something else.
Regards
Ronni
OZ2RNH
Hi, new member, and new to the QO-100.
Got a bunch of uplink parts from a fellow ham, but i don't believe any of it has ever been used on QO-100, so i got a few questions.
Between the parts there was a 6 element helix RHCP antenna, homemade - but not sure who made it.
Would something like that be useful for QO-100, or am i better of building a dual feed antenna, poty or something like that ?
My main goal would be SSB and digi modes.
A few pictures of the Helix antenna.
Regards
Ronni
OZ2RNH