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Old 15th Sep 2019, 6:26 pm   #81
G6Tanuki
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Default Re: Antenna recommendation for 40 and 80M bands

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Originally Posted by budkor22 View Post
I checked connectivity between all the Mains sockets E pins on the walls with DMM, and they are all connected.

I rechecked the E pins and Mains water pipes, but there is NO connection at all.
For houses built in the last 50-60 years the water-main 'incomer' has been a plastic pipe.

Same goes for gas-pipes - which have either been plastic or a metal-pipe-with-yellow-plastic-oversheathing.

Using water/gas-pipes for any kind of RF grounding/earthing is stupid.
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Old 15th Sep 2019, 7:13 pm   #82
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Default Re: Antenna recommendation for 40 and 80M bands

Depends. We put a new shower room in the house, and the water was connected from the mains copper pipe under the sink, and brought into the shower room. They used 100% copper pipes.

Same with the upstairs bathroom, 100% copper pipes. That length of copper pipes would be enough earthing to tune up to about 40M bands and above. Not quite 80M though

If in the event of emergency or natural disaster scenario, if your only way getting out another person for help were via wireless comms, and you had an HF rig, then anything to load up as an antenna and works could be life saving means
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Old 15th Sep 2019, 8:04 pm   #83
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Default Re: Antenna recommendation for 40 and 80M bands

Even prior to this thread, my limited understanding was that if I update from TT to TN, then the installer must ensure that all pipework must be connected (the word "bonded" is used) back to the Main Earth Terminal. I think this is what the RSGB book says. One issue here is that this adds to the cost of installing the new consumer unit. The chances are that in an older house, there will be no existing bonding, or the existing conductors will need upgrading to meet current regs. If the point where the water mains pipe comes in to the house is totally concealed by fitted kitchen units, then I assume even more work is involved in getting access to that.

Bonding the pipes back to the MET does not mean they are being used to create an earth, it simply ensures that are at the same potential.

It will be interesting to get three suitably qualified Part17 electricians in to do quotes and see if they all propose that exactly the same work is required.

B
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Old 15th Sep 2019, 8:10 pm   #84
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Default Re: Antenna recommendation for 40 and 80M bands

Some plumbers wind PTFE tape on when they use compression fittings. Earth continuity is not then reliable. Current regs require earth bonding wires from main earthpoint to taps, sinks etc.

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Old 15th Sep 2019, 8:55 pm   #85
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Default Re: Antenna recommendation for 40 and 80M bands

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The current trend towards PME (TN-C-S) wiring systems has nothing to do with safety and everything to do with cost.
TT systems applied at household level require an isolation transformer rated to carry the maximum household load of 15kVA - an item which will cost several thousand pounds. TT systems also require that the householder install and maintain an "installation earth electrode" to which exposed conductive parts of the installation can be bonded. Electricity suppliers are , perhaps rightly, concerned that this requirement may not always be satisfied, leading to possibly hazardous situations.
Strangely, my DNO is happy to provide, at zero cost, such a transformer (it sits on a pole about 200 yards away from my house) along with the incoming overhead lines and TT ground-spike.

None of the locals or myself have ever been under any pressure to switch from this TT-grounded 3-phase setup. I'm happy with this.

The old "PME" approach [which required loads of earth-bonding between pipework/significant metal-lumps like cooking-ranges/wood-burning-stoves and the like] has always seemed a horribly overcomplex and expensive nuisance to me; I suspect it was the product of the same mindset that inflicted the 13A "ring-main" on us.

OK, if you've got an old-style PME system then you have the big issue that your local-earth arrangement [which includes your radio earth] may - under fault-conditions - end up carrying the entire 'neutral current' of your own installation and that of other customers on the same feed. Equally, it's not a good idea to 'export' the earth from a PME/TN-C-S system to a shed/shack or other remote location.

For me, this is a good-enough reason to do all you can to avoid such a system!

When I've been faced with remote sheds/shacks/garages I've never 'exported' the TN-C-S earth, and have essentially had it "TT"d at the remote location with an earth-spike and RCD. The armour of the SWA cable being grounded *ONLY* at the head-end and not connected to anything at the remote location.
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Old 15th Sep 2019, 10:22 pm   #86
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Default Re: Antenna recommendation for 40 and 80M bands

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Some plumbers wind PTFE tape on when they use compression fittings. Earth continuity is not then reliable. Current regs require earth bonding wires from main earthpoint to taps, sinks etc.

David
True. I did some DIY plumbing myself too, and PTFE tapes are mostly used for outside taps. But for joining the copper pipes, they do soldering with blow torch. Professional plumbers seem swearing by the soldering and using copper pipes for quality of the works even today.

If you used plastic pipes and PTFE tapes, then you are amateurs, they say.
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Old 15th Sep 2019, 10:29 pm   #87
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Arrow Re: Antenna recommendation for 40 and 80M bands

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Originally Posted by budkor22 View Post
I am still not understanding your comment "at least one Mains socket 'E' pin should be connected to the water pipe," when none of them is connected.
O.K.: let me try to bring out the significant points.

First: the 'E' pin of every 230-v.a.c. socket in your house must eventually make a good electrical contact with the real earth - i.e. ground. That is an essential safety requirement. That could be achieved by all the 'E' wires from every socket being connected to the metal pipe that brings water into your house, the electrical connection being as close to the point as possible where the pipe enters your house.

Second: current electrical safety standards require that all permanently exposed / permanently fixed metalwork in your house must also be connected to ground. This is also a safety requirement; it is termed 'electrical bonding'. Also refer to post #87 above.
[Note: That is my understanding of this part of current electrical regulations but you should not rely exclusively on my wording, since I am not a qualified electrician.]

Third: the reason for the above is that should an electrical fault develop whereby the 'live' conductor of the mains wiring comes into contact with any such unearthed metalwork - e.g. a copper pipe (which could, for example, be for water or gas) - and should a person touch that item with any other part of his / her body which is also in contact with earth, the person could receive an electrical shock - which, under some circumstances, could be fatal; if not fatal, still likely to cause 'consequent injury'.

Fourth: The above is especially relevant where copper piping has non-conductive unions in its run. Such a union will separate the (hopefully) earthed part of that pipe from the insulated other part of that pipe. In such cases, both parts of that pipe should be earthed, possibly by means of a jumper wire between the two parts.
Modern-built properties make extensive use of plastic pipe; older ones tend to use copper and a mix of copper and lead. It is a bad idea to have a mix of metal and plastic.

Hopefully, matters are clearer now.

Al.
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Old 15th Sep 2019, 10:36 pm   #88
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Thumbs up Re: Antenna recommendation for 40 and 80M bands

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Now not wishing to frighten the OP unduly, anyone here agree with my reasoning - or is there a flaw in it somewhere ?
I am simply trying to help the OP.
Quote:
Originally Posted by Boulevardier View Post
Yes, I definitely agree - that house wiring must be checked urgently. There should be bonding of electrical earth to water pipes somewhere near where they come into the house.
Thank you.

Al.
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Old 15th Sep 2019, 10:38 pm   #89
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Default Re: Antenna recommendation for 40 and 80M bands

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Originally Posted by Bazz4CQJ View Post
Even prior to this thread, my limited understanding was that if I update from TT to TN, then the installer must ensure that all pipework must be connected (the word "bonded" is used) back to the Main Earth Terminal. I think this is what the RSGB book says. One issue here is that this adds to the cost of installing the new consumer unit. The chances are that in an older house, there will be no existing bonding, or the existing conductors will need upgrading to meet current regs. If the point where the water mains pipe comes in to the house is totally concealed by fitted kitchen units, then I assume even more work is involved in getting access to that.

Bonding the pipes back to the MET does not mean they are being used to create an earth, it simply ensures that are at the same potential.

It will be interesting to get three suitably qualified Part17 electricians in to do quotes and see if they all propose that exactly the same work is required.

B

I am not quite understanding Earthing system and bonding etc too. Only thing I ensured was there is no connection between the mains water pipes and the 230V wall sockets' E pins. And there was none.

So it was a make shift antenna I put up just to keep me going for a few days, and it worked fine without any problems.

But now, with the arrival of the 1:1 balun I ordered, it has been taken off, and put up in the middle of the garden as inverted V with the balun. I haven't transmitted yet, but on reception, it seems about 2 S point higher than the previous antenna, and SWR is between 1.5 - 2: 1 without ATU.

Will run this antenna for a few days or weeks, and will move on to a Loop with tuner. I have a couple of tuning caps, so should be able to build a loop tuner.

I had an MFJ loop tuner for 20-10M in the past, and had great QRP CW fun with it running as an indoor loop antenna.

Would also like to try out a doublet and GP afterwards, and choose the best suitable one for this location.

Last edited by budkor22; 15th Sep 2019 at 10:51 pm.
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Old 15th Sep 2019, 10:40 pm   #90
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Default Re: Antenna recommendation for 40 and 80M bands

I just searched Google for an answer to the question "What are the advantages of retaining a TT mains supply?"

Lots of hits, mainly of forums frequented by qualified electricians, who seem unable to agree about anything much on this subject. The issues to consider seem all but endless. Seems like TT and TN both have pros & cons, and I was wrong to believe that installing a new consumer unit would require a mandatory change from TT to TN.

Lets hope that nobody uses PTFE tape on a compression fitting and then someone heats it up with a blow lamp to free up the nut!

B
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Old 15th Sep 2019, 10:50 pm   #91
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Default Re: Antenna recommendation for 40 and 80M bands

Quote:
Originally Posted by Skywave View Post
Quote:
Originally Posted by budkor22 View Post
I am still not understanding your comment "at least one Mains socket 'E' pin should be connected to the water pipe," when none of them is connected.
O.K.: let me try to bring out the significant points.

First: the 'E' pin of every 230-v.a.c. socket in your house must eventually make a good electrical contact with the real earth - i.e. ground. That is an essential safety requirement. That could be achieved by all the 'E' wires from every socket being connected to the metal pipe that brings water into your house, the electrical connection being as close to the point as possible where the pipe enters your house.

Second: current electrical safety standards require that all permanently exposed / permanently fixed metalwork in your house must also be connected to ground. This is also a safety requirement; it is termed 'electrical bonding'. Also refer to post #87 above.
[Note: That is my understanding of this part of current electrical regulations but you should not rely exclusively on my wording, since I am not a qualified electrician.]

Third: the reason for the above is that should an electrical fault develop whereby the 'live' conductor of the mains wiring comes into contact with any such unearthed metalwork - e.g. a copper pipe (which could, for example, be for water or gas) - and should a person touch that item with any other part of his / her body which is also in contact with earth, the person could receive an electrical shock - which, under some circumstances, could be fatal; if not fatal, still likely to cause 'consequent injury'.

Fourth: The above is especially relevant where copper piping has non-conductive unions in its run. Such a union will separate the (hopefully) earthed part of that pipe from the insulated other part of that pipe. In such cases, both parts of that pipe should be earthed, possibly by means of a jumper wire between the two parts.
Modern-built properties make extensive use of plastic pipe; older ones tend to use copper and a mix of copper and lead. It is a bad idea to have a mix of metal and plastic.

Hopefully, matters are clearer now.
All good thank you.

But I am not interested in finding out about how electrical earth has to bond to water pipes ... etc. I feel that is looked after by the power supply company, and we are the consumers, who are using their service and supply. I feel more so now, it is something that is in the domain of the professional electricians or power company, and I don't want to have anything to do with it

The electricity had been newly installed and rewired not long ago by the professionals, and everything works all fine. I had done some checks on the mains electrical earth system following checking procedure demonstrated by the youtube video of somebody, and it was very good earthing system within the good spec. not long ago. And all the mains socket E pins are connected to each other, which means that it is connected to some sort of proper earthing system. That is all I can be sure, and it is fine with me.

As I have repeated about 10 times in this thread, that only thing I have checked and ensured was that the power sockets E pins and the mains water pipes have no electrical connectivity prior to attachment of the coax earth to the outside tap using more than 5 meters of heavy duty thick wire.

It worked all fine as few days of makeshift antenna, and now had been taken off.
I am just going to work on with the LF antennas, not the earthing system, because everything is working fine. If there is problems with power, we will contact the power supply company, and they will sort it out for us

Last edited by budkor22; 15th Sep 2019 at 11:18 pm.
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Old 15th Sep 2019, 11:35 pm   #92
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Arrow Re: Antenna recommendation for 40 and 80M bands

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Originally Posted by budkor22 View Post
I am not interested in finding out about how electrical earth has to bond to water pipes ... etc. I feel that is looked after by the power supply company, and we are the consumers, who are using their service and supply. I feel more so now, it is something that is in the domain of the professional electricians or power company, and I don't want to have anything to do with it
Hi! O.K., you've now made your feelings and intentions on the subject of "electrical wiring in the home, safety of" quite clear.
I - and others here - have given you our advice with our best intentions. Ultimately, since it is your house, it's your decision as to what to do, if anything: that I accept & respect.
And with that, I have nothing to add on this sub-thread: it will only be mere repetition.

Best of luck with your aerial experiments: I hope you ultimately reach success.

Al.
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Old 16th Sep 2019, 12:15 pm   #93
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Default Re: Antenna recommendation for 40 and 80M bands

I do appreciate your info and advice on the Earthing matter in mains electricity. But it is way above me, I feel. I just want to leave the mains electricity issues with the power company's support, if ever needed.

Thank you for your advice and info. All the best.
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Old 16th Sep 2019, 2:52 pm   #94
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Default Re: Antenna recommendation for 40 and 80M bands

Yes forget the Electrical installations, lets get back to the real project
I am pleased that you are taking the time to try different antennas, difficult to compare as propagation changes so quickly, what is good one day can easily be poor the next.
When we were testing antenna designs we had a huge antenna farm and was able to switch between many antennas types to achieve factual comparison readings
At our club house we have verticals for 80 and 160 meters, large matching coils and variable capacitors housed at foot of masts.45 ft high with four hi_hat radials which are part of the support guys
Fan dipole for 80/40/20, , good results, no ATU
We also use a hexbeam,on a 60 ft tower, wind has wrecked it twice so we have redesigned using stainless steel instead of aluminium quite good.
We have a Loop antenna and find it good for 20 meter dx
Hustler 5 band vertical, works fairly well but not fair to compare with our other antennas
The propagation is quite different from the 80 M vertical compared to the 80M dipole
The height of your antennas and type of ground change the resonance frequency ( capacitance between ground and antenna)
Keep up your interest and let me know when you get " on air"
cheers
MM0HDW
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Old 16th Sep 2019, 5:52 pm   #95
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Default Re: Antenna recommendation for 40 and 80M bands

I use two aerials, one is a Wellbrook loop for receive (on top of the greenhouse as far from any other houses as possible) and a 12m vertical with an SGC auto tuner for transmit. The RX is quite low noise, TX terribly inefficient, with only 5W (on PSK31) have got to Oz.
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Old 16th Sep 2019, 6:57 pm   #96
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Default Re: Antenna recommendation for 40 and 80M bands

This strategy of a mag-loop for receive, and the best conventional aerial you can for Tx, does look like it could be one approach to try cope with the noise problem.

I'm just waiting to have some trees cut down, and I'll be pursuing this again. I only have the time to get involved with this in the winter months; the last two winters formed part of a very shallow learning curve .

Referring back to the link on the small vertical dipole in post 31, I've searched Google and it does not seem like that antenna has been taken up to any great extent, or that short, non-resonant vertical dipoles are much used, but perhaps we are missing out on something good?

B
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Old 16th Sep 2019, 7:08 pm   #97
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Default Re: Antenna recommendation for 40 and 80M bands

Quote:
Originally Posted by James Duncan View Post
Yes forget the Electrical installations, lets get back to the real project
I am pleased that you are taking the time to try different antennas, difficult to compare as propagation changes so quickly, what is good one day can easily be poor the next.
When we were testing antenna designs we had a huge antenna farm and was able to switch between many antennas types to achieve factual comparison readings
At our club house we have verticals for 80 and 160 meters, large matching coils and variable capacitors housed at foot of masts.45 ft high with four hi_hat radials which are part of the support guys
Fan dipole for 80/40/20, , good results, no ATU
We also use a hexbeam,on a 60 ft tower, wind has wrecked it twice so we have redesigned using stainless steel instead of aluminium quite good.
We have a Loop antenna and find it good for 20 meter dx
Hustler 5 band vertical, works fairly well but not fair to compare with our other antennas
The propagation is quite different from the 80 M vertical compared to the 80M dipole
The height of your antennas and type of ground change the resonance frequency ( capacitance between ground and antenna)
Keep up your interest and let me know when you get " on air"
cheers
MM0HDW

Yes, this is true. I still have the 20m long power cable from caravan in the loft. When switching between the loft wire and outside wire V, the reception on 80M is totally different.

On the loft wire, most of the 80M is not readable due to high level of band noise, when switch over to the outside V, the noise clears, and reception is very clean.

But on 40M band and above, the loft wire is better maybe due to the height.

Please let me know the usual freq. and also time of the day you are on AIR on HF, and I will listen out for you, and will give you shout. cheers.
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Old 29th Sep 2019, 3:54 pm   #98
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Default Re: Antenna recommendation for 40 and 80M bands

I have been using an inverted V dipole for 80m now, and it is working OK. I contacted a station in North London last night, and also a portable station in Orkney, Isle of Wyre with population of 9 people on 80m too. I was excited to be able to contact these stations.

No balun, just half wave dipole in inverted V config.
No RF feedback in the shack, and SWR is 1:3, but tunes up to 1:1.5

This antenna tunes up for 20M as well, but not good on 40M for some reason.
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Old 29th Sep 2019, 5:38 pm   #99
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Default Re: Antenna recommendation for 40 and 80M bands

Well done
that is exactly the way a correctly cut dipole will perform ,
20 works well on a 80 meter antenna as it is the harmonic.
if you want 40 just add an extra dipole to your antenna,and all will work well.
as to SWR, it is often overlooked that a dipole has an impedance of 73 ohms and the coax is 50 ohm so 75/50 = near 1.5 to 1 is the best real SWR that should be expected, anything up to 2-1 is fine.
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Old 29th Sep 2019, 6:54 pm   #100
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Great advice and info. Thank you.
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