Topband: Balloon Supported Vertical

Grant Saviers grants2 at pacbell.net
Mon Nov 8 19:03:33 EST 2021 

Another choice is to buy a cylinder, which is what most consumer/retail 
users now do in the US.  The 150 ft^3 cylinders were going for around 
$180 empty pre covid.  The specific cylinder can be refilled or 
exchanged which has the advantage of free pressure recertification (at 
least at my welding supplier).

DON'T buy "private" used cylinders (w/o documentation) as they are often 
pirated rentals and won't be refilled or might have residual really 
deadly gas. eg silane SiH4

Grant KZ1W

On 11/8/2021 15:02, Adrian wrote:
> Here, for full size 90cm - 1m balloons it works out around $20 au helium 
> per balloon, plus $2 balloon plus $5-10 average line loss.
> 
> So a night session is around $30 au in costs on average, and only when 
> conditions are right, otherwise you are wasting your time and $.
> 
> The bigger the industrial bottle you can purchase the better the deal. 
> Also you can negotiate price with the supplier, I cut my original
> 
> offer price nearly in half as well is 25% off my rental. Recommended 
> retail compared to a trade customer pricing has big pricing difference.
> 
> In the USA you should be able to do it for $20 or less per balloon. Also 
> using too big a balloon is wasting helium $ and increasing line break risk.
> 
> I use difference inflation levels for each band 630m biggest to 80m 
> smallest. If I re-use balloons, i only use them on 80m , which is the 
> smaller inflation.
> 
> A bigger balloon gets hit harder and creates much more line stress with 
> sudden gusts. The advantage of using 3/4 w setups is if the break is at the
> 
> 1/4w point (trees house etc) the impedance change to the amp is not so 
> dramatic and the LDMOS amp in low survives the event on swr trip.
> 
> Watching the swr real-time on the SPE, and have a finger on the halt 
> button has saved gear here. A sudden wind change and a 2nd story gutter 
> contact can just
> 
> blow the line at the contact point during TX, and its start again, but 
> the amp remains good.
> 
> As the line changes angle the swr changes with it, and with experience 
> trouble can be avoided.
> 
> The lift force should just be in excess of the total line weight, less 
> than 2:1.
> 
> 
> vk4tux
> 
> 
> On 9/11/21 08:32, Mark - N5OT wrote:
>> > we used a 4-5' - "rubber"  balloon. (could've been latex or 
>> something similar)
>>
>> So did I.  A 4 foot diameter balloon has 33-ish cubic feet of volume. 
>> Looks like Helium is running about $2 a cubic foot = $66 per use?
>>
>> Gad.  Too pricey for N5OT.
>>
>> 73 - Mark
>>
>>
>> On 11/8/2021 4:21 PM, Adrian wrote:
>>> Also the disposable party balloon bottles are a waste of $ and would 
>>> only inflate 2 to 3 of the balloons here.
>>>
>>> Industrial gas supply is required to make it viable.
>>>
>>> "
>>>
>>> ABN 95 000 029 729
>>> Riverside Corporate Park
>>> 10 Julius Ave, North Ryde NSW 2113
>>> Tel: 131 262 www.boc.com
>>> Email: contact at boc.com
>>> 2nd June 2021
>>> Dear Adrian Fewster,
>>> BOC special offer on compressed gas for Adrian Fewster.
>>> Thank you for your enquiry regarding the supply of gases and 
>>> equipment from BOC Limited. Our customers
>>> are assured of BOC's genuine commitment to providing premium gas 
>>> products and services in addition to
>>> ongoing technical support, and the convenience of our large national 
>>> distribution network.
>>> Pricing for products which are purchased by you but which are not 
>>> listed in the special offer pricing table
>>> below will be charged at BOC's standard or list prices for each such 
>>> individual product as varied from time
>>> to time unless otherwise agreed. The gas pricing for the products 
>>> listed in the special offer pricing table
>>> below will be varied in proportion to changes in BOC's standard 
>>> prices for each individual product and the
>>> rental pricing will vary in line with BOC's standard charges unless 
>>> otherwise agreed. This does not apply to
>>> prices for LPG, Refrigerant, Helium and Acetylene products which will 
>>> vary in line with Supplier increases as
>>> they are incurred.
>>> All prices below are GST exclusive. Price may vary if purchased from 
>>> a different BOC Gas & Gear or Gas
>>> Agent.
>>> Gas CodeDescriptionCylinder
>>> Volume
>>> Annual
>>> Quantity
>>> Delivered
>>> Price**
>>> Rental (per
>>> day)##
>>> 124GBALLOON GAS G SIZE7.1m31$398.31$0.6822
>>> For refrigerant products a refrigerant reclaim and fluoro activity 
>>> levy of $2.38/kg also applies.
>>> ** Where a standard local delivery option is available
>>> ## Rental Pricing is described as Service Charges in BOC's General 
>>> Terms and Conditions of Supply
>>> Rental Pricing
>>> Cylinder CodeRental (per day)
>>> 'G' Size$0.6822
>>> You may accept the special offer pricing above in the manner set out 
>>> in the last paragraph of this letter. By
>>> accepting the special offer pricing above, you warrant that you do 
>>> not have a binding exclusive supply
>>> arrangement with another supplier for any or all of the products 
>>> listed in the special offer pricing table
>>> above (or for products substantially similar to those listed) 
>>> applicable to your site(s) where the products are
>>> to be used.
>>> The Agreement so formed between BOC and you for the supply of the 
>>> products listed in the special offer
>>> pricing table above will consist of the terms and conditions set out 
>>> in this special offer pricing letter
>>> together with the BOC General Terms and Conditions of Supply. (as 
>>> amended from time to time) (accessible
>>> from our website (www.boc.com.au)).
>>> Under this Agreement we will supply and you will purchase all of your 
>>> requirements for the products
>>> covered by this Agreement. This Agreement will commence on the date 
>>> of formal acceptance and continues
>>> until you or we terminate it by giving a minimum of 6 (six) months' 
>>> notice expiring at the end of the
>>> minimum period of 1year(s) or by either party giving a minimum of 1 
>>> (one) months' notice after the expiry
>>> of the minimum period, or until it is terminated under the BOC 
>>> General Terms and Conditions of Supply.
>>> At BOC we believe that our business is here to help your business so 
>>> if you have any queries please feel
>>> free to get in touch with me at jamie-lee.palelei at boc.com.
>>> This offer will be loaded to your customer account within two 
>>> business days. "
>>>
>>>
>>> vk4tux
>>>
>>>
>>> On 9/11/21 07:54, W7TMT - Patrick wrote:
>>>> Regarding the helium…
>>>>
>>>> Be advised the gas used by the party stores these days is almost 
>>>> always a mixture and not pure helium. That’s means considerably less 
>>>> lift. You’ll likely need to source the good stuff from a industrial 
>>>> gas supplier.
>>>>
>>>> W7TMT
>>>> ________________________________
>>>> From: Topband<topband-bounces+w7tmt=outlook.com at contesting.com> on 
>>>> behalf of Mark - N5OT<r-emails at n5ot.com>
>>>> Sent: Monday, November 8, 2021 1:17:53 PM
>>>> To: TopBand List<topband at contesting.com>
>>>> Subject: Re: Topband: Balloon Supported Vertical
>>>>
>>>> Been There Done That
>>>>
>>>> You might want to figure the weight of what you have to lift. One would
>>>> think it was, like, duh, you make a wire vertical and fill a balloon
>>>> full of helium and ... but it turns out you need to be careful about 
>>>> the
>>>> weight of the wire and insulators and you need to project how much
>>>> helium you can use and how much lift you will need and ... all that.
>>>>
>>>> Just saying all that because the last thing you want to find out is,
>>>> after you've got it all together, you just can't get it up in the air.
>>>>
>>>> I seem to recall I needed more like a 3 or 4 foot balloon to lift mine.
>>>>
>>>> And be careful of the sticker shock on the gas.  I thought it was a lot
>>>> of money 20 years ago.  Rumor has it, it has not gone down in price.
>>>>
>>>> The first one worked well until I had a bad wind.
>>>>
>>>> The second one had some kind of corona arc off the top of the wire 
>>>> which
>>>> popped the (relatively expensive) balloon after only a couple 
>>>> minutes of
>>>> testing it out.  Or something.  It popped on a clear calm day but under
>>>> Full Power.
>>>>
>>>> Anyway, that wrecked my day.  I decided it wasn't fun any more and have
>>>> been using more conventional 160 meter verticals since.
>>>>
>>>> I think we wrote it up in the NCJ but don't remember and have slept
>>>> since then.
>>>>
>>>> Oh sorry, you asked where to get the balloons.  I think I got mine from
>>>> a party supply store.  It was not mylar.
>>>>
>>>> Note - Googling reminds me of these facts:
>>>>
>>>> Helium can lift 1 gram per litre.
>>>> A balloon 2 feet in diameter will contain 118 litres of helium.
>>>> That will lift 118 grams of antenna, = 4.1 ounces.
>>>> 132 feet of bare #18 solid copper wire weighs 10.4 ounces.
>>>>
>>>> A 2 foot balloon filled with helium will not lift a 160 vertical 
>>>> made of
>>>> #18 wire, not to mention any extra line or insulators, etc.
>>>>
>>>> But a 4 foot balloon will lift a little over 2 pounds.
>>>>
>>>> Now I'm having nightmares again.
>>>>
>>>> 73 - Mark N5OT
>>>>
>>>>
>>>> On 11/8/2021 2:48 PM, Dick Bingham wrote:
>>>>> Greetings All
>>>>>
>>>>> I want to try a balloon supported Vertical for 160.
>>>>> Any advice on sources for balloons? Mylar material
>>>>> and diameters up to 2-feet would be my choice.
>>>>>
>>>>> 73. Dick/w7wkr at CN97uj
>>>>> _________________
>>>>> Searchable Archives:http://www.contesting.com/_topband  - Topband 
>>>>> Reflector
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