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Re: GW4DGU 10368 dish feed
Denis Stanton G0OLX
Hi All
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I am using one of Chris feeds on my 1.25 metre offset fed dish with says it has a .65 FD I have successfully decoded 3 stations on 10 GHz over the weekend I am starting on the TX side, so hope to be able to work some of the bigger stations off the moon soon Best 73’s Denis G0OLX
On 13 Feb 2020, at 14:32, Dave via Groups.Io <drdavidnewman@...> wrote:
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Re: ?utf-8?q?_=5BUKMicrowaves=5D?= Cardiff Gnu course - Cancelled due to low number of applicants
Paul G8AQA
May do better with numbers near the Midlands. I
am wondering about the next Midlands Round Table or the Telford
Hamfest both of which have good facilities.
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Paul G8AQA
On 13/02/2020 12:07, Andy G4JNT wrote:
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Re: GW4DGU 10368 dish feed
Hello Keith,
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I have one of the same. It will work well with a 0.6 f/D ratio according to Chris in an email to me. 73, Dave G4GLT
On 13 Feb 2020, at 14:07, Keith <Keith@...> wrote:
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GW4DGU 10368 dish feed
Apologies to Chris but I cant seem to get a direct link to him.
I bought one of his feeds, an ADF10368FOR7 10 ghz dish feed, but cant for the life of me find any info on it. I would like to know power handling capabilities, focal point given the plastic feed cover with its markings, and any other info available etc. S/no is 20171124f. I bought it to use with an offset dish that was later discarded from the plans, but now I find it could be a possible goer :) Any info at all would be appreciated. Cheers Keith
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Re: ?utf-8?q?_=5BUKMicrowaves=5D?= Cardiff Gnu course - Cancelled due to low number of applicants
Suspect most people in the uWave area who are interested will have already done the course. It could usefully have been advertised on the two Tech group, RSGBTechnical and RSGB-Workshop, and also the LF Group. It's not just uWavers interested in GNU Radio I copied to the tech ones at the last minute but too late for a couple of people - didn't think of LF one at the time. Was it also announced on GB2RS ? Andy
On Thu, 13 Feb 2020 at 11:57, Derek Kozel <derek@...> wrote: Just to be clear, the Roundtable is still on! We have three of the 4-5 talks already confirmed and one that's pending. Anyone who has a story of operating or contesting that they'd be willing to share I'd love to hear from you. Also ideas of what topics you'd like to see a talk on.
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Re: ?utf-8?q?_=5BUKMicrowaves=5D?= Cardiff Gnu course - Cancelled due to low number of applicants
Just to be clear, the Roundtable is still on! We have three of the 4-5 talks already confirmed and one that's pending. Anyone who has a story of operating or contesting that they'd be willing to share I'd love to hear from you. Also ideas of what topics you'd like to see a talk on.
It is sad about the GNU Radio course, we had a lab with computers and RF equipment booked. I hope we can sign up interest for running it as an independant event later in the year. A big thanks to John for the organizing he's done on this and Heather for her SDR expertise and time. Derek MW0LNA On Thursday, February 13, 2020 11:31 GMT, "SAM JEWELL via Groups.Io" <jewell@...> wrote: Sorry to hear that, John. Perhaps the next one will get enough take-up. I also feel sorry for the organisers of the Cardiff MRT. You tried. Some you win...... Sam, G4DDK Sent from Yahoo Mail for iPad On Thursday, February 13, 2020, 11:27 am, John Worsnop <johnworsnop@...> wrote:
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Re: Cardiff Gnu course - Cancelled due to low number of applicants
SAM JEWELL
Sorry to hear that, John.
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Perhaps the next one will get enough take-up. I also feel sorry for the organisers of the Cardiff MRT. You tried. Some you win...... Sam, G4DDK
On Thursday, February 13, 2020, 11:27 am, John Worsnop <johnworsnop@...> wrote:
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Cardiff Gnu course - Cancelled due to low number of applicants
John Worsnop
Hello folks, I'm sorry to have to announce that we've just not managed to get enough people to express interest in the Gnu Radio course in Cardiff in March to make it viable this time. I have to pull the plug now as I needed to order the hardware (from China, and that's very tricky at the moment) and firm up the bookings. That would involve me spending my own money up front and I was just not prepared to do that without minimum numbers signed up. I'm asking the RSGB please, if they can "freeze" the legacy funding application and we'll try and organise the course again later in the year. Possible venues would be Cambridge, or the Friday before RSGB convention in MK. Any other offers of a venue for 25 people with food and desks/power (real ones, where you can offer to actually do something to help us, not just suggestions) would be gratefully accepted. I now need to find something to do in Cardiff on the Sunday as I've booked accommodation already! 73 John G4BAO
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Re: +12V Supply to Masthead
ian hope (2E0IJH)
For those that dont know the use of 55-0-55 on construction sites is to do with touch voltage, it's deamed to be a safe voltage that won't kill you, using a centre tapped transformer to supply the 110v, you actually will only get a shock of 55v.
Ian
2E0IJH
Sent: Thursday, February 13, 2020 at 12:13 AM
From: "Chris Bartram G4DGU" <chris@...> To: UKMicrowaves@groups.io Subject: [UKMicrowaves] +12V Supply to Masthead This has been an interesting discussion. Apologies for changing the
Subject, but As my interest is in getting a decent high current power supply to my new dish mount I've been giving the subject quite a lot of though over the last few months. Having seen GM4PMK's system I'm also planning to use the 110V AC approach! There are a number of advantages. The use of an AC system balanced about ground means that there's effectively only half of that voltage flapping around wrt ground, reducing the risk of of shock if a fault occurs. Compare that with standard UK mains where the line conductor carries 240V AC wrt ground. Also, being AC, electrolytic corrosion in connectors is vastly reduced. I have had experience of connectors carrying moderate DC supplies in my own systems failing from this in the past: it really doesn't take a lot of moisture ... I have looked at the use of high current DC cables, but the cost of decent, suitable, cables and connectors is very high. 73 Chris G4DGU
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+12V Supply to Masthead
Chris Bartram G4DGU <chris@...>
This has been an interesting discussion. Apologies for changing the Subject, but
As my interest is in getting a decent high current power supply to my new dish mount I've been giving the subject quite a lot of though over the last few months. Having seen GM4PMK's system I'm also planning to use the 110V AC approach! There are a number of advantages. The use of an AC system balanced about ground means that there's effectively only half of that voltage flapping around wrt ground, reducing the risk of of shock if a fault occurs. Compare that with standard UK mains where the line conductor carries 240V AC wrt ground. Also, being AC, electrolytic corrosion in connectors is vastly reduced. I have had experience of connectors carrying moderate DC supplies in my own systems failing from this in the past: it really doesn't take a lot of moisture ... I have looked at the use of high current DC cables, but the cost of decent, suitable, cables and connectors is very high. 73 Chris G4DGU
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Re: 12v supply to masthead
ian hope (2E0IJH)
Inherently safer than 240v especially if supplied from 55-0-55 type transformer
Ian
Sent: Wednesday, February 12, 2020 at 5:50 PM
From: "SAM JEWELL via Groups.Io" <jewell@...> To: UKMicrowaves@groups.io Subject: Re: [UKMicrowaves] 12v supply to masthead I also have a 110V builder’s transformer in the shack and a yellow 14m ‘mains’ lead, in my duct, to the back of the dish.
I was attracted by the ability to use 90-240v ac input SMPSUs to power the gear out there.
GM4PMK put me onto this some years ago. He uses it at his Mull QTH, with his 23cm EME system.
55 -0- 55v transformers, with preterminated plugs and socket leads, as well as suitable separate cable and hardware, are readily available from ToolStation etc at reasonable prices.
Seems the sensible way to go as long as you are sensible and take precautions to filter the SMPSU outputs.
73 de Sam, G4DDK
Sent from Yahoo Mail for iPad On Wednesday, February 12, 2020, 5:32 pm, John Lemay <john@...> wrote:
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Re: 12v supply to masthead
SAM JEWELL
I also have a 110V builder’s transformer in the shack and a yellow 14m ‘mains’ lead, in my duct, to the back of the dish.
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I was attracted by the ability to use 90-240v ac input SMPSUs to power the gear out there. GM4PMK put me onto this some years ago. He uses it at his Mull QTH, with his 23cm EME system. 55 -0- 55v transformers, with preterminated plugs and socket leads, as well as suitable separate cable and hardware, are readily available from ToolStation etc at reasonable prices. Seems the sensible way to go as long as you are sensible and take precautions to filter the SMPSU outputs. 73 de Sam, G4DDK
On Wednesday, February 12, 2020, 5:32 pm, John Lemay <john@...> wrote:
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Re: 12v supply to masthead
John Lemay
All
Many thanks for your thoughtful suggestions.
I’m really rather cautious about sending 240v mains up the mast ! Perhaps the suggestion of 110v is as far as I would go – in fact I quite like that idea. No matter how careful I am, there have been odd occasions where a rogue cable has parted from the loom and wrapped itself round a bit of the Versatower, with awkward consequences.
I do already have a bench power supply that will allow me to run up to 80v DC up the mast, and that’s why the idea of a converter at the top was in my mind.
Regarding a 12v supply with remote sensing, that is what I currently (!) use. I too was very wary about RF pickup on the sense leads, and tackled that possibility by using screened cable and ferrite clamp-ons at both ends. I’m pleased to say this has worked well – so far. But there must be a limit to how much voltage drop can be compensated, and the power supply info is completely lacking in that department.
Meanwhile, my mast was luffed over for the weekend storm, and will remain that way for the action replay in a few days time.
Thanks again
John G4ZTR
From: UKMicrowaves@groups.io [mailto:UKMicrowaves@groups.io] On Behalf Of ian hope (2E0IJH)
Sent: 12 February 2020 10:52 To: UKMicrowaves@groups.io Subject: Re: [UKMicrowaves] 12v supply to masthead
Watch what version Olflex you use, The Tray grade versions are not UV stable.
Ian 2e0ijh
Sent: Wednesday, February 12, 2020 at 10:25 AM Dear All,
Have used both mains to mast-head and 110V also.
I agree that using sense wires is very risky in a high RF environment.
For mains to the mast-head, make sure all the metal is bonded and earthed and that there are the usual residual current protections required for outdoor circuits.
Since chunky bonding and earthing is needed for lightning protection, this is no great burden. Make sure everything is properly labelled, so that anyone working on the tower is aware of the hazard.
One point about cable- ordinary mains cable is likely to embrittle with UV exposure, creating a safety issue.
There are special outdoor high UV exposure cables available- Olflex is the brand we use- that will last well.
Regards,
Alwyn
_____________________________________________________
Alwyn Seeds, Director _____________________________________________________
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Re: 12v supply to masthead
ian hope (2E0IJH)
Watch what version Olflex you use, The Tray grade versions are not UV stable.
Ian
2e0ijh
Sent: Wednesday, February 12, 2020 at 10:25 AM
From: "alwyn.seeds1" <a.seeds@...> To: "UK Microwaves groups.io" <UKMicrowaves@groups.io> Subject: Re: [UKMicrowaves] 12v supply to masthead Dear All,
Have used both mains to mast-head and 110V also.
I agree that using sense wires is very risky in a high RF environment.
For mains to the mast-head, make sure all the metal is bonded and earthed and that there are the usual residual current protections required for outdoor circuits.
Since chunky bonding and earthing is needed for lightning protection, this is no great burden. Make sure everything is properly labelled, so that anyone working on the tower is aware of the hazard.
One point about cable- ordinary mains cable is likely to embrittle with UV exposure, creating a safety issue.
There are special outdoor high UV exposure cables available- Olflex is the brand we use- that will last well.
Regards,
Alwyn
_____________________________________________________
Alwyn Seeds, Director
SynOptika Ltd., 114 Beaufort Street, London, SW3 6BU, England. SynOptika Ltd., Registered in England and Wales: No. 04606737 Registered Office: 114 Beaufort Street, London, SW3 6BU, United Kingdom. _____________________________________________________
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Re: 12v supply to masthead
Richard GD8EXI
You can easily limit, in the shack, the max voltage the PSU can go to in the case of a sensing failure. However I can see that having the sensing wires near the antenna could be an issue without some care.
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Remote voltage sensing is standard practice on boats where you have long, low voltage, high current cables. For example from an alternator or generator to a battery bank with 10 metres of cable carrying 100 amps. These systems fail safe with the output voltage dropping in the case of a sensing failure. Richard GD8EXI
On 12/02/2020, 09:59, "Dominique Dehays" <f6dro@...> wrote:
Hi all
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Re: 12v supply to masthead
Mark
Hi John
Just to say that 48v to 12v is common in the cellular world and so
professional grade units are available, i have some here that came from a 12v
stealth PA unit and they are very well built.
73 <DE Mark>
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Re: 12v supply to masthead
alwyn.seeds1
Dear All,
Have used both mains to mast-head and 110V also. I agree that using sense wires is very risky in a high RF environment. For mains to the mast-head, make sure all the metal is bonded and earthed and that there are the usual residual current protections required for outdoor circuits. Since chunky bonding and earthing is needed for lightning protection, this is no great burden. Make sure everything is properly labelled, so that anyone working on the tower is aware of the hazard. One point about cable- ordinary mains cable is likely to embrittle with UV exposure, creating a safety issue. There are special outdoor high UV exposure cables available- Olflex is the brand we use- that will last well. Regards, Alwyn _____________________________________________________ Alwyn Seeds, Director SynOptika Ltd., 114 Beaufort Street, London, SW3 6BU, England. SynOptika Ltd., Registered in England and Wales: No. 04606737 Registered Office: 114 Beaufort Street, London, SW3 6BU, United Kingdom. _____________________________________________________
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Re: 12v supply to masthead
G4LDR
I have used a DC to DC converter at the top of my mast for the last 13 years. It is 13.8V 20A o/p for about 22 to 30V i/p. I supply 27V from the shack. The unit I have is designed to power 13.8V equipment from a 27V vehicle supply.
73 Neil G4LDR
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Re: 12v supply to masthead
John Worsnop
I run my EME system off 28V fed by 4×7m lengths of 8mm stranded car audio cable taking around 27 Amps from a Psu indoors. No sense wires. For the bands with 12V PAs I have a further 28-12V 40A meanwell switcher at the dish with a metre or so to the focus box. Works well. 73 John
On Wed, 12 Feb 2020, 09:46 ian hope (2E0IJH), <ian@...> wrote:
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Re: 12v supply to masthead
Dominique Dehays
Hi all I'm a bit reckless as I run 240v ac up to the tower.My current drain is too high for BT. A pair of isolating transformers helps. But I believe that running the psu reference wires up the tower is even more reckless:what is going to happen if a wire breaks (believe me,it will)73 Dom Envoyé depuis mon smartphone Samsung Galaxy.
-------- Message d'origine -------- De : "ian hope (2E0IJH)" <ian@...> Date : 12/02/2020 10:46 (GMT+01:00) À : UKMicrowaves@groups.io Objet : Re: [UKMicrowaves] 12v supply to masthead Funny this, Ian SEK had similar thoughts, we were talking about the other day
Ian
2E0IJH
Sent: Wednesday, February 12, 2020 at 9:16 AM
From: "Neil Smith G4DBN" <neil@...> To: UKMicrowaves@groups.io Subject: Re: [UKMicrowaves] 12v supply to masthead I have a remote Meanwell SMPS which runs on a +-55VAC feed from a big
yellow site transformer. Feels a bit safer than running 240 up the mast. The unit is rated for 90-264 VAC in and seems to behave fine with the 105V or so it gets via the feed cable. Neil G4DBN On 12/02/2020 09:02, Jon Eyre wrote: > Can't you just mast mount the 13.5v supply. I have both my 13 and 24v > power supplies mast mounted and they have been there for a couple of > years with no problem, I just leave them switched on to eliminate > condensation. > Jon G7TZZ
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