|
Re: Wimo 23cms 44ele [1 Attachment]
Rex Cameron <cathar.gnostic@...>
Yes but much better, really excites the parasitic elements and due to the length diameter ratio its much more broad banded. I dumped every other dipole design because I could not get 1:1. ZL4IV
|
|
|
|
Re: Wednesday night 23cm Digifest
Neil Smith G4DBN
...and I’m in Slough. Not quite as exotic, but still a long way from my radios.
toggle quoted messageShow quoted text
Neil G4DBN
|
|
|
|
Re: Wimo 23cms 44ele [1 Attachment]
ian hope (2E0IJH)
So a a coaxial dipole like G4CQM type antennas?
Ian
2E0IJH
Sent: Wednesday, November 16, 2016 at 7:34 PM
From: "Rex Cameron cathar.gnostic@... [ukmicrowaves]" To: "ukmicrowaves@..." Subject: RE: [ukmicrowaves] Wimo 23cms 44ele [1 Attachment] [Attachment(s) from Rex Cameron included below]
This is my version of the perfect driven element for my 32el yagi. Tried all designs but only this one works at +200w and at SWR 1:1.
It's been in use for a number of years with my regular evening ragchew at a distance of about 300km.
ZL4IV
|
|
|
|
Re: Wimo 23cms 44ele
Rex Cameron <cathar.gnostic@...>
This is my version of the perfect driven element for my 32el yagi. Tried all designs but only this one works at +200w and at SWR 1:1. It's been in use for a number of years with my regular evening ragchew at a distance of about 300km. ZL4IV
|
|
|
|
432 and Above EME Newsletter for November 2016
rein0zn@...
Hello All,
The 432 MHz and Above EME Newsletter for November 2016 by K2UYH can be downloaded from: http://www.nitehawk.com/rasmit/em70cm.html -- Enjoy -- Tnx Al. 73 Rein W6SZ
|
|
|
|
Re: Tripod turntable [1 Attachment]
geoff Blake
Thanks Mike, I can see it now - a microwavers queue outside B&Q. Geoff################################################# Geoff Blake, G8GNZ JO01fq: Chelmsford, Essex, UK <geoff@...> or <melecerties@...> Using Linux: Ubuntu 14.04 on Intel or Debian on UltraSparc and Apple OS X El Capitan on my Macbook Pro. Avoiding Micro$oft like the plague. #################################################
On 16 November 2016 at 14:09, mb.golfmad@... [ukmicrowaves] <ukmicrowaves@...> wrote:
|
|
|
|
Re: Tripod turntable [1 Attachment]
Pete - GM4BYF
Mike
A very useful lead.
I have discovered that if you look up “Lazy Susan Turntables” on eBay, they
come in all sorts of sizes.
The six inch is rated at 227kg and the twelve inch at more than 300kg.
Think that may be the basis of my dish system which I wish to set up for EME
.
73
Pete GM4BYF
From: mb.golfmad@... [ukmicrowaves]
Sent: Wednesday, November 16, 2016 2:09 PM
To: ukmicrowaves@...
Subject: Re: [ukmicrowaves] Tripod turntable [1
Attachment] Hi Geoff,
|
|
|
|
Re: Wimo 23cms 44ele
John Lemay
Phil
You are correct. I was on ‘KST when you raised the issue and you got a quick reply which at the time I assumed was right. But I have an old driven element here, minus it’s plastic case and “sticky stuff”, and it must be like yours – open circuit to DC.
I used to run a pair of 44 ele’s and over time I decided that the VSWR was getting higher, and took one apart to see if I could understand why. I’m none the wiser having done so. Measured at the feed point, it was about 1.4 to 1.
John G4ZTR
From: ukmicrowaves@... [mailto:ukmicrowaves@...]
Sent: Wednesday, November 16, 2016 14:11 To: ukmicrowaves@... Subject: [ukmicrowaves] Wimo 23cms 44ele
I had a classic fright on Sunday when I convinced myself the yagi was misbehaving. I thought the driven element was supposed to be short circuit to DC, as did others. However on dismantling I can confirm its very well made - or in my case, was - and intentionally open circuit.
Phil 'YPQ
|
|
|
|
Wimo 23cms 44ele
g3ypq
I had a classic fright on Sunday when I convinced myself the yagi was misbehaving. I thought the driven element was supposed to be short circuit to DC, as did others. However on dismantling I can confirm its very well made - or in my case, was - and intentionally open circuit. Phil 'YPQ
|
|
|
|
Re: Tripod turntable
mike G6TRM
Hi Geoff,
Your wish is my command!! cheers Mike G6TRM
|
|
|
|
Re: Tripod turntable
Pete - GM4BYF
Excellent idea Mike.
Looks like a trip to B&Q in the offing.
73
Pete GM4BYF
From: mb.golfmad@... [ukmicrowaves]
Sent: Wednesday, November 16, 2016 1:33 PM
To: ukmicrowaves@...
Subject: [ukmicrowaves] Tripod turntable
Hi All,
|
|
|
|
Re: Tripod turntable
geoff Blake
Any chance of a photo Mike? Geoff################################################# Geoff Blake, G8GNZ JO01fq: Chelmsford, Essex, UK <geoff@...> or <melecerties@...> Using Linux: Ubuntu 14.04 on Intel or Debian on UltraSparc and Apple OS X El Capitan on my Macbook Pro. Avoiding Micro$oft like the plague. #################################################
On 16 November 2016 at 13:29, mb.golfmad@... [ukmicrowaves] <ukmicrowaves@...> wrote:
|
|
|
|
Tripod turntable
mike G6TRM
Hi All,
|
|
|
|
Re: Wednesday night 23cm Digifest
Sorry, im in Munich this week Best Regards Tim Hague M0AFJ m0afj@... 07930-409145
-------- Original message -------- From: "'Mark G0MGX' mark.g0mgx@... [ukmicrowaves]" <ukmicrowaves@...> Date: 08/11/2016 03:24 (GMT+01:00) To: ukmicrowaves@... Subject: RE: [ukmicrowaves] Wednesday night 23cm Digifest Unfortunately I’m working in Dubai this week so no signals from me.
Mark G0MGX
From: ukmicrowaves@... [mailto:ukmicrowaves@...]
Certainly be interesting to compare ISCAT-A/B with MSK144 for aircraft scatter. The off-axis path approach using the Heathrow western glide path as a common volume for scattering will also be worth another look. Neil G4DBN
|
|
|
|
Re: Length of 2m feeder to Sg Labs transverter
ian hope (2E0IJH)
Yes we've had creeping centres with many contest cable, Not seem to be issue now have changed to crimp plugs, but time will tell, will be a PA in there in the future, Have had conversations with Bert PE1RKI, Prob run something like 4mm Sq supply tails, Have suitable Large Ip rated boxes, as use them in trade (Electrical Engineer)
Ian
2E0IJH
Sent: Tuesday, November 15, 2016 at 12:16 PM
From: "'Tony Collett' anthony.collett@... [ukmicrowaves]" To: ukmicrowaves@... Subject: RE: [ukmicrowaves] Length of 2m feeder to Sg Labs transverter
I like Peter’s comment re cable type – you’ve already seen the creeping centre conductor issue I think Ian?
My comment was a bit “in cheek” but realistically so long as the loss in the cable is less than the gain of the transverter on Rx you will be OK, you only need a small increase in noise on the 2m Rx when the transverter is connected (use too much gain and you risk reducing your dynamic range though not likely to be much of an issue for you?). Likewise on Tx, so long as you have enough power to drive it OK. I would imagine that even basic UR67/RG214 would be plenty good enough over that sort of distance but do make sure everything is protected from the weather if you want it to be reliable.
Another dumb comment – make sure the DC cable is capable of whatever current you might take in future without incurring voltage drooping on speech peaks. Hardly a problem for the basic transverter but if you add a PA??
Look forward to working you in due course. 73 Tony G4NBS
From: ukmicrowaves@... [mailto:ukmicrowaves@...]
Ian Both John and Tony have given you correct answers.
Of 9913 contra LMR-400 I would suggest that the LMR-400 is a slightly better choice as the longitudinal air dielectric volume of 9913 will slowly absorb moisture from the outside air IF it runs outside your house. Temp cycling et al. This are effects that can crawl up on your installation over the space of a year or three.
More germane to a successful long-term installation is the quality of the termination of the cables with correct connectors, And sealing of the transitions/joints..
Peter Ebsworth, Forland, Sotra. From: ukmicrowaves@... [mailto:ukmicrowaves@...]
Hi all what would be a acceptable length of feeder at 2m (146mhz) be for a mast head mounted SG labs transverter and still get a acceptable performance.
Planing the Masthead setup, have extended the the 2 Control LEDS onto a cable so can monitor the unit at shack
Ian 2E0IJH
|
|
|
|
Re: Steel box section masts
Dave G8KHU
You can get 50x50x3 and 80x80x3 galvanized from metals4U in 6m lengths, but I can't see 60x60x3 box there. https://www.metals4u.co.uk/mild-steel/galvanised/box-section/80mm-x-80mm-x-3mm/p13633 Be aware of the weight though, a rough estimate of the weight of 6m of 50x50x3 is 29kg and for the 80x80x3 is 46kg. Raising and lowering that with antennas as well isn't something to be taken lightly (excuse pun) from a safety perspective. Eddie's suggestion of the rotator at the bottom is well worth considering as it puts the rotator weight at the bottom and means that the rotating part of the feeders are at the bottom of the mast also where they can easily be accessed in the event of problems. Coincidently I'm just in the process of revamping my permanent scaffold pole mast and have relocated the rotator to the bottom for the same reasons. I've attached a picture which may be of interest. The left hand pole is steel and is sunk into concrete, the centre pole (also steel) is sunk into the concrete also and is hinged at the bottom. This pole carries the rotator and two thrust bearings and clams to the left hand pole by scaffold clamps when raised. The right hand pole is the mast itself and here I've gone for aluminium to minimise weight. If any of that's of interest feel free to plagiarise :) Dave G8KHU
|
|
|
|
Re: Length of 2m feeder to Sg Labs transverter
Tony G4NBS
I like Peter’s comment re cable type – you’ve already seen the creeping centre conductor issue I think Ian?
My comment was a bit “in cheek” but realistically so long as the loss in the cable is less than the gain of the transverter on Rx you will be OK, you only need a small increase in noise on the 2m Rx when the transverter is connected (use too much gain and you risk reducing your dynamic range though not likely to be much of an issue for you?). Likewise on Tx, so long as you have enough power to drive it OK. I would imagine that even basic UR67/RG214 would be plenty good enough over that sort of distance but do make sure everything is protected from the weather if you want it to be reliable.
Another dumb comment – make sure the DC cable is capable of whatever current you might take in future without incurring voltage drooping on speech peaks. Hardly a problem for the basic transverter but if you add a PA??
Look forward to working you in due course. 73 Tony G4NBS
From: ukmicrowaves@... [mailto:ukmicrowaves@...]
Sent: Tuesday, November 15, 2016 07:35 To: ukmicrowaves@... Subject: RE: [ukmicrowaves] Length of 2m feeder to Sg Labs transverter
Ian Both John and Tony have given you correct answers.
Of 9913 contra LMR-400 I would suggest that the LMR-400 is a slightly better choice as the longitudinal air dielectric volume of 9913 will slowly absorb moisture from the outside air IF it runs outside your house. Temp cycling et al. This are effects that can crawl up on your installation over the space of a year or three.
More germane to a successful long-term installation is the quality of the termination of the cables with correct connectors, And sealing of the transitions/joints..
Peter Ebsworth, Forland, Sotra. From: ukmicrowaves@... [mailto:ukmicrowaves@...]
Hi all what would be a acceptable length of feeder at 2m (146mhz) be for a mast head mounted SG labs transverter and still get a acceptable performance.
Planing the Masthead setup, have extended the the 2 Control LEDS onto a cable so can monitor the unit at shack
Ian 2E0IJH
|
|
|
|
Re: Long path
g4bao
I also worked LA3EQ on 23 using QRA64 last night. Jan uses a similar system to Sam and we completed easily. I have to confess that the mode takes a bit of getting used to, as for most of the QSO I couldn't even see Sam's keyed signal on the waterfall never mind hear it. It only appeared when he sent the single tone test signal. I described the experience as being "a bit Harry Potter" at the time! Cynics should note that this system uses no callsign lookup like JT65 can. Think you can't do EME from a small back garden? Think again.
On 15 Nov 2016 09:06, "Sam Jewell jewell@... [ukmicrowaves]" <ukmicrowaves@...> wrote:
|
|
|
|
Long path
SAM JEWELL
Using the good conditions (lowest path loss) during last nights 'supermoon' and the new QRA64 weak signal digital mode, G4BAO and I were able to complete a QSO on 23cm off the moon. The signals were marginal at best between the 1.9/2.3m dishes with around 200W (in the shack, much less at my antenna) and didn't decode for me on every over. The great thing about QRA64 is that it is error checked, so you know from the EME path delay time, signal levels, doppler and contents that the exchange was genuine and not via tropo back scatter.
John's signals decoded on JT65C earlier when he was working LA3EQ, but were far less reliable. We are far from being the smallest pair of stations to successfully work off the moon, but it was nevertheless the culmination of tests between John and myself going back some time. The moon did appear later yesterday evening after the showery weather cleared the east coast. It was quite impressive to see although not as impressive as the rising moon the previous evening when driving back east from Stansted! 73 de Sam, G4DDK
|
|
|
|
Re: Length of 2m feeder to Sg Labs transverter
Peter <pete-ebs@...>
Ian Both John and Tony have given you correct answers.
Of 9913 contra LMR-400 I would suggest that the LMR-400 is
a slightly better choice as the longitudinal air dielectric volume of 9913 will
slowly absorb moisture from the outside air IF it runs outside your house. Temp
cycling et al. This are effects that can crawl up on your installation over the space of a year or three.
More germane to a successful long-term installation is the quality of the termination of the cables with correct connectors, And sealing of the transitions/joints..
Peter Ebsworth, Forland, Sotra. From:
ukmicrowaves@... [mailto:ukmicrowaves@...]
Hi all what would be a acceptable length of feeder at 2m (146mhz) be for a mast head mounted SG labs transverter and still get a acceptable performance.
Planing the Masthead setup, have extended the the 2 Control LEDS onto a cable so can monitor the unit at shack
Ian 2E0IJH
|
|
|
