Amateur Radio Homebrew (Shack Culture)

User avatar
PanBiker
Site Administrator
Site Administrator
Posts: 7425
Joined: 23 Jan 2012, 13:07
Location: Barnoldswick - In the West Riding of Yorkshire, always was, always will be.

Re: Amateur Radio Homebrew (Shack Culture)

Post by PanBiker » 09 Aug 2017, 15:26

Adhesive heat shrink tubing arrived so I set to finalising the antenna. I cut a couple of extra 10mm lengths of the bushing to extend the existing ones on the reflector side of the hub slightly to give a bit more purchase. I wrapped a single layer of double sided tape at the ends of the bushes and cut 40mm of the heat shrink for each leg. I put a rubber grommets on the elements to buffer the heat shrink rather than shrink it on the sharp edge of the Acetal. I have a purpose built heat gun for shrinking the tube, I secured the bush end first and once gripped moved out to the element. It has worked out well and the adhesive has gripped everything quite securely.

This is the reflector with the extra 10mm of bushing inserted to give more purchase. You can just see that the existing 40mm in the T piece did not leave a huge amount proud.

Image

No extra required on the driven element ends as they have extended bushes to allow for the spreader on the hub.

Image

I put two shorter pieces on the centre of the driven element to stop water ingress at that point.

Image

Here is the completed array looking down from the top, the driven element is at the back and the reflector at the front of this image.

Image

A view with it flipped over, cable entry shown and the extra T piece for the mast mounting.

Image

Apart from the testing the antenna is now finished. Any other work that may be required will be with the feeder. I may have to create a choke on the lead depending on how it performs when I get it hooked up.
Ian

User avatar
Stanley
Global Moderator
Global Moderator
Posts: 44060
Joined: 23 Jan 2012, 12:01
Location: Barnoldswick. Nearer to Heaven than Gloria.

Re: Amateur Radio Homebrew (Shack Culture)

Post by Stanley » 10 Aug 2017, 02:46

Tidy work Ian......
Stanley Challenger Graham
Stanley's View
scg1936 at talktalk.net

"Beware of certitude" (Jimmy Reid)
The floggings will continue until morale improves!

User avatar
PanBiker
Site Administrator
Site Administrator
Posts: 7425
Joined: 23 Jan 2012, 13:07
Location: Barnoldswick - In the West Riding of Yorkshire, always was, always will be.

Re: Amateur Radio Homebrew (Shack Culture)

Post by PanBiker » 20 Aug 2017, 13:20

I have another small turning job Stanley. I need another short length of Acetal turning down to 15mm and then threading at one end to make an insulated adaptor for the top of the fibreglass pole I am going to use for a portable mast. It's actually a 2m long telescopic landing net handle so has a brass bush fitted at the end threaded out, (3/8 BSF ) to accept the screw in landing net, the existing pole diameter is slightly over the 15mm needed for the T piece so will require the adaptor.

The thread used for fishing accessories is standardised and used on bank sticks for rod rests and keep nets, same on landing nets. Used them all for donkeys years but never given a thought as to what the thread actually is, (it does the job). I found the info on the Maggot Drowner website which is a forum for all things fishing so to speak. :extrawink:
Ian

User avatar
Stanley
Global Moderator
Global Moderator
Posts: 44060
Joined: 23 Jan 2012, 12:01
Location: Barnoldswick. Nearer to Heaven than Gloria.

Re: Amateur Radio Homebrew (Shack Culture)

Post by Stanley » 21 Aug 2017, 03:36

No problem Ian, call round any morning but not tomorrow (Tuesday) as I shall be in Skipton arranging my funeral...... :laugh5: :laugh5: :laugh5:
Stanley Challenger Graham
Stanley's View
scg1936 at talktalk.net

"Beware of certitude" (Jimmy Reid)
The floggings will continue until morale improves!

User avatar
PanBiker
Site Administrator
Site Administrator
Posts: 7425
Joined: 23 Jan 2012, 13:07
Location: Barnoldswick - In the West Riding of Yorkshire, always was, always will be.

Re: Amateur Radio Homebrew (Shack Culture)

Post by PanBiker » 21 Aug 2017, 09:12

Travelling afield for the service Stanley, can the locals not do anything for you? You get a divi at the Coop you know. :extrawink:

My job will probably be later in the week anyway, Wednesday is taking our Ruby back day, really looking forward to the smart motorway upgrade misery, Thelwall to the A500, right where I need to be. :sad:
Ian

User avatar
Stanley
Global Moderator
Global Moderator
Posts: 44060
Joined: 23 Jan 2012, 12:01
Location: Barnoldswick. Nearer to Heaven than Gloria.

Re: Amateur Radio Homebrew (Shack Culture)

Post by Stanley » 22 Aug 2017, 03:19

I would have gone local Ian but my daughters are comfortable with the Skipton firm as they did their mother's arrangements so I defer to them.
You know when to come. Funnily enough, I already had a 3/8" BSF die in stock but one of the ones the NE Mafia sent me that arrived yesterday is another one. They have their sources you know...... By the way, BSF is old fashioned but it's a good thread, in essence it's a fine Whitworth form.
Stanley Challenger Graham
Stanley's View
scg1936 at talktalk.net

"Beware of certitude" (Jimmy Reid)
The floggings will continue until morale improves!

User avatar
Stanley
Global Moderator
Global Moderator
Posts: 44060
Joined: 23 Jan 2012, 12:01
Location: Barnoldswick. Nearer to Heaven than Gloria.

Re: Amateur Radio Homebrew (Shack Culture)

Post by Stanley » 24 Aug 2017, 06:03

You know where I am every morning Ian.....
Stanley Challenger Graham
Stanley's View
scg1936 at talktalk.net

"Beware of certitude" (Jimmy Reid)
The floggings will continue until morale improves!

User avatar
PanBiker
Site Administrator
Site Administrator
Posts: 7425
Joined: 23 Jan 2012, 13:07
Location: Barnoldswick - In the West Riding of Yorkshire, always was, always will be.

Re: Amateur Radio Homebrew (Shack Culture)

Post by PanBiker » 24 Aug 2017, 10:12

We have had both cats at the vet this morning for their annual booster jabs, we take them separately as we only have one basket. We still get the double pet discount though if we take them on the same day. Still £81.00 though even with the discount, Mrs Marsh is pleased with both of them though, both in good nick for their ages, Millie is rocking on 16 and still a hunter killer, Primrose is 11 and still frightened of mice!

I'll pop in tomorrow.
Ian

User avatar
Stanley
Global Moderator
Global Moderator
Posts: 44060
Joined: 23 Jan 2012, 12:01
Location: Barnoldswick. Nearer to Heaven than Gloria.

Re: Amateur Radio Homebrew (Shack Culture)

Post by Stanley » 25 Aug 2017, 04:04

Make it morning Ian, I have Ian from Bancroft in the afternoon for heavy duty decisions.
Stanley Challenger Graham
Stanley's View
scg1936 at talktalk.net

"Beware of certitude" (Jimmy Reid)
The floggings will continue until morale improves!

User avatar
PanBiker
Site Administrator
Site Administrator
Posts: 7425
Joined: 23 Jan 2012, 13:07
Location: Barnoldswick - In the West Riding of Yorkshire, always was, always will be.

Re: Amateur Radio Homebrew (Shack Culture)

Post by PanBiker » 25 Aug 2017, 12:37

I did a fag packet drawing and took my materials down to Stanley this morning. He has produced me this:

Image

Thanks again Stanley.

Just what I need to utilise my landing net handle as a support for the Moxon antenna. The handle is two piece and 2m long when extended fibreglass pole, one section fits inside the other and telescopes out to full length. Each section is tapered and the top section has a brass ferule that this adapter will now screw into. The body of the adaptor is turned to 15mm to fit the connecting T piece on the antenna.

It will allow me to get the antenna array one full wavelength above ground level on the 144MHz band but to be free standing will require guying. I will make a disk drilled out to about 16mm which will sit slightly down from the top of the pole. I'll drill this out at four points around the periphery and fit some lightweight guys and tensioners, the array will then be rotatable through the guying system. On a large pole with much bigger antennas guying points would require bearings but we are not in this league with this portable set up. Weight is of the essence as the whole kit and caboodle will have to be carried to the operating summits of choice.
Ian

User avatar
Stanley
Global Moderator
Global Moderator
Posts: 44060
Joined: 23 Jan 2012, 12:01
Location: Barnoldswick. Nearer to Heaven than Gloria.

Re: Amateur Radio Homebrew (Shack Culture)

Post by Stanley » 25 Aug 2017, 13:18

A pleasure.... You should have mentioned the guy adaptor, I have some small bearings and we could have made a disc with one in the middle so that the pole could be rotated without altering the guy wires......
Stanley Challenger Graham
Stanley's View
scg1936 at talktalk.net

"Beware of certitude" (Jimmy Reid)
The floggings will continue until morale improves!

User avatar
PanBiker
Site Administrator
Site Administrator
Posts: 7425
Joined: 23 Jan 2012, 13:07
Location: Barnoldswick - In the West Riding of Yorkshire, always was, always will be.

Re: Amateur Radio Homebrew (Shack Culture)

Post by PanBiker » 25 Aug 2017, 14:48

I think I worded my post slightly wrong, the pole will rotate within the guyed disk which is probably a better way of putting it. The guys will not require moving. Of course it would be a lot smoother if there was a bearing involved, it would need to have a centre around 16mm diameter to sit near the top of the tapered pole if you did have anything to hand.

The system we used to have for the radio club was guyed on pole mounted bearings on each length of scaffold used. We had a heavy duty hinged base with a thrust bearing for the bottom of the pole and locking mechanism to lock the rotation. Three sets of guys if we put the antennas to 60ft two sets for 40ft and you only needed one for a 20ft setup.
Ian

User avatar
Stanley
Global Moderator
Global Moderator
Posts: 44060
Joined: 23 Jan 2012, 12:01
Location: Barnoldswick. Nearer to Heaven than Gloria.

Re: Amateur Radio Homebrew (Shack Culture)

Post by Stanley » 26 Aug 2017, 03:09

I've had a look, no suitable size Ian. Sorry.
Stanley Challenger Graham
Stanley's View
scg1936 at talktalk.net

"Beware of certitude" (Jimmy Reid)
The floggings will continue until morale improves!

User avatar
PanBiker
Site Administrator
Site Administrator
Posts: 7425
Joined: 23 Jan 2012, 13:07
Location: Barnoldswick - In the West Riding of Yorkshire, always was, always will be.

Re: Amateur Radio Homebrew (Shack Culture)

Post by PanBiker » 26 Aug 2017, 09:00

No worries Stanley a light perspex or polycarbonate disk or rectangle with suitable holes will do the job. It only has to be adjustable on occasion, not a heavy duty cycle of rotation.

I have some and will set to with the hacksaw, drill and files.
Ian

User avatar
Stanley
Global Moderator
Global Moderator
Posts: 44060
Joined: 23 Jan 2012, 12:01
Location: Barnoldswick. Nearer to Heaven than Gloria.

Re: Amateur Radio Homebrew (Shack Culture)

Post by Stanley » 27 Aug 2017, 02:48

I used to have a reel of light steel woven rope and spent half an hour looking for it yesterday but I must have given it away......
Stanley Challenger Graham
Stanley's View
scg1936 at talktalk.net

"Beware of certitude" (Jimmy Reid)
The floggings will continue until morale improves!

User avatar
PanBiker
Site Administrator
Site Administrator
Posts: 7425
Joined: 23 Jan 2012, 13:07
Location: Barnoldswick - In the West Riding of Yorkshire, always was, always will be.

Re: Amateur Radio Homebrew (Shack Culture)

Post by PanBiker » 27 Aug 2017, 08:43

Thanks Stanley but bog standard nylon guy line will be perfectly OK for this job. It's 2 meters of fiberglass pole that needs holding to the vertical. We never used steel cables even on 60ft scaffold pole masts supporting 5m long beams. Modern synthetic materials do everything asked of them. We did use steel line with turnbuckles on each end of our 250ft long wire antenna down at the RR sports field but that was a horizontal tensioning job on a very heavy copper covered steel line. My 20m long wire antenna is fastened at each end with paracord which is synthetic woven construction around a twisted core, very versatile stuff with multiple uses.
Ian

User avatar
Stanley
Global Moderator
Global Moderator
Posts: 44060
Joined: 23 Jan 2012, 12:01
Location: Barnoldswick. Nearer to Heaven than Gloria.

Re: Amateur Radio Homebrew (Shack Culture)

Post by Stanley » 28 Aug 2017, 03:26

Good! :biggrin2:
Stanley Challenger Graham
Stanley's View
scg1936 at talktalk.net

"Beware of certitude" (Jimmy Reid)
The floggings will continue until morale improves!

User avatar
PanBiker
Site Administrator
Site Administrator
Posts: 7425
Joined: 23 Jan 2012, 13:07
Location: Barnoldswick - In the West Riding of Yorkshire, always was, always will be.

Re: Amateur Radio Homebrew (Shack Culture)

Post by PanBiker » 03 Sep 2017, 18:37

I have furthered the pole adaptation a bit today. I made this polycarbonate hub to attach the guys near the top of the pole and still allow rotation. The pole is tapered so the hub has been drilled and filed out to about 17mm diameter the pole is nominally 16mm at the top and with the screw in 15mm adaptor it will sit about 3" to 4" below the antenna. At this point the mast will have free rotation within the hub. You can just see that this position is set by a few turns of insulation tape on the mast to support the hub just before its binding point on the taper. A hole in each corner and these rounded off will allow the guys to be attached.

Image

The two sections of the pole are only friction locked as when in its original use as a landing net handle it is invariably in a downward horizontal plane. When using it as a vertical support I will just wrap a bit of tape round the mast at the friction lock point, its not supporting a lot of weight so this will be perfectly adequate and equally quickly reversible for disassembly.
Ian

User avatar
Stanley
Global Moderator
Global Moderator
Posts: 44060
Joined: 23 Jan 2012, 12:01
Location: Barnoldswick. Nearer to Heaven than Gloria.

Re: Amateur Radio Homebrew (Shack Culture)

Post by Stanley » 04 Sep 2017, 02:34

:biggrin2:
Stanley Challenger Graham
Stanley's View
scg1936 at talktalk.net

"Beware of certitude" (Jimmy Reid)
The floggings will continue until morale improves!

User avatar
PanBiker
Site Administrator
Site Administrator
Posts: 7425
Joined: 23 Jan 2012, 13:07
Location: Barnoldswick - In the West Riding of Yorkshire, always was, always will be.

Re: Amateur Radio Homebrew (Shack Culture)

Post by PanBiker » 04 Sep 2017, 09:32

I have ordered a bargain reel of Paracord and some guy tensioners which should come to me mid week. I could get 4 ready made guys 2.4m long for around £4.99 with free postage Or 100m of 3mm Paracord for £6.50 and 5 guy tensioners for £1.49, I went for the latter also both with free postage. :extrawink:
Ian

User avatar
PanBiker
Site Administrator
Site Administrator
Posts: 7425
Joined: 23 Jan 2012, 13:07
Location: Barnoldswick - In the West Riding of Yorkshire, always was, always will be.

Re: Amateur Radio Homebrew (Shack Culture)

Post by PanBiker » 08 Sep 2017, 13:48

My Paracord came on Wednesday and the tensioners on Thursday. So before site matters took over I set about the hub and guys. Here is my nice new 100m drum of 3mm Paracord, the construction of this diameter is 3 central twisted strands around a single core so actually 4 and then surrounded by the woven outer shield. Its all of synthetic construction and can be sealed with heat to stop fraying, this batch is Army Green.

Image

While I was waiting for the tensioners to come I couldn't resist testing a couple of loop knots that I thought I might use to fasten the guys to the hub. I found a couple of rings to try them on, first is a Single Davy.

Image

and the second a Double Davy tested on the little pocket knife steel.

Image

Both are essentially the same knot but the double passes twice through the forming loop and I reckon tightens down a lot neater. Both are self tightening under strain. I tried both of these on the hub but found that once tightened down there was no flexibility or give at the joint so I considered a fixed loop variant but it is quite hard to tie these and produce four with the same loop. I abandoned any other variants and decided to just apply the KISS principle. Here is the hub with the guys securely attached but still loose and articulate, I have just used a simple double loop knot, it wont pull through the hole and does the job. I have trimmed off the ends and heat sealed them.

Image

On to the business end with the small aluminium tensioners.

Image

Here they are attached with the same double loop knot.

Image

Testing to make sure I have them the right way.

Image

Gathered, wrapped and ready to go.

Image

A bit of basic geometry told me they needed to be at least 2.8m long, I have made them 3.5m, any surplus can be taken up with the tensioner and its better to have too much than not enough. :smile:
Ian

User avatar
Stanley
Global Moderator
Global Moderator
Posts: 44060
Joined: 23 Jan 2012, 12:01
Location: Barnoldswick. Nearer to Heaven than Gloria.

Re: Amateur Radio Homebrew (Shack Culture)

Post by Stanley » 09 Sep 2017, 04:13

As usual, a tidy job...... :biggrin2:
Stanley Challenger Graham
Stanley's View
scg1936 at talktalk.net

"Beware of certitude" (Jimmy Reid)
The floggings will continue until morale improves!

BillHowcroft
Donor
Posts: 100
Joined: 19 Aug 2017, 17:39
Location: Derby

Re: Amateur Radio Homebrew (Shack Culture)

Post by BillHowcroft » 09 Sep 2017, 12:45

Double Davy
That's not a knot I remember from my days in the Boy Scouts.

User avatar
PanBiker
Site Administrator
Site Administrator
Posts: 7425
Joined: 23 Jan 2012, 13:07
Location: Barnoldswick - In the West Riding of Yorkshire, always was, always will be.

Re: Amateur Radio Homebrew (Shack Culture)

Post by PanBiker » 09 Sep 2017, 15:16

Strictly speaking it's a loop but requires a knot to form it. :extrawink:

Double Davy

What I settled on is a knot in the true sense I suppose, or is that not a knot either? I wasn't in the Scouts and can be easily confused. :laugh5:

Maybe this will help: Knot
Ian

User avatar
PanBiker
Site Administrator
Site Administrator
Posts: 7425
Joined: 23 Jan 2012, 13:07
Location: Barnoldswick - In the West Riding of Yorkshire, always was, always will be.

Re: Amateur Radio Homebrew (Shack Culture)

Post by PanBiker » 14 Sep 2017, 22:15

In order to use my new Moxon antenna in anger I need to recommission my Standard C58 144MHz Multimode Portable Transceiver. I have just taken delivery of 12 AA size NiMH rechargeable batteries, I need 10 to power the transceiver. I went for the 3000mAh rated cells which should give a reasonable operation time when in use.
I need to find (at reasonable cost) or build a suitable charger which will need to be of constant current design. A bit of inbuilt smart technology to detect when the stack is charged and then switch to a trickle to avoid overcharging is required in the design. When the transceiver was new (over 30 years ago now) it was originally fitted with NiCad cells so its original charger, supplied with the transceiver is a constant voltage model and no longer suitable for the new battery types. I want to charge them in-situ so the charger will have to deliver around 15v at at a constant 300mA, this would charge the complete stack in about 15-16 hours. Charge time can be decreased by charging at a higher current but for my application it is not really necessary as it will not have a particularly high duty cycle.
Ian

Post Reply

Return to “Amateur Radio”

Who is online

Users browsing this forum: No registered users