Re: Topband: G3YRO 160m Receiving Loop

There are a very interesting series of loops and amplifiers coming out of Cross Country Wireless, in particular the latest uses an aluminium bicycle wheel rim, note just the rim which can be bought at a modest price. On a suitable base it is self-supporting and needs to be simply cut with a hack

Re: Topband: Desiccant in Beverage Boxes

Steel mesh is good. From distant memory a nylon mesh of 0.8mm square is used in the food industry. This turns out to be the stuff ladies use to fluff out their ballroom gowns and is very cheap. Perhaps you could snip a piece without it being noticed ? I also found the fibreglass net used for

Re: Topband: Rx splinter

You might look at Cross Country Wireless for a high performance multicoupler: http://www.crosscountrywireless.net/multicoupler.htm Look at the IP3 David G3UNA-G6CP -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of vk2wf Sent: 01 February 2019 22:03 To:

Re: Topband: ARRL DXCC - 160 Meters - Station Location and Boundary

It's the shared receive-only site that I will build for my club. I can't think of a better application of subs for members who live in high density housing as we do. LF is now completely out of the question for all but a privileged few. David G3UNA/G6CP -Original Message- From: Topband

Re: Topband: ARRL DXCC - 160 Meters - Station Location and Boundary

A few UK clubs are doing this or have it in mind, including my own. I think it is the best thing a club can do for its members. David G3UNA/G6CP " I also think that building and maintaining a shared Community Low Noise RX Receiver Site would make a great DX Club project and service."

Re: Topband: FCP for lower power

might glean from that. Thanks again and I will let you know how things turn out. 73 David G3UNA/G6CP -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Guy Olinger K2AV Sent: 20 November 2018 18:46 To: David Cutter Cc: TopBand List Subject: Re: Topband

Topband: FCP for lower power

I am planning an inverted L over a folded counterpoise as K2AV. My power levels will likely be about one third of the design levels for the K2AV design. I can imagine during tune up or adjustments that I might hit half the power level for short periods, so my component values need not be so

Re: Topband: Preamp on RX antenna`s in contest environment.

Cross Country Wireless pre-amp have exceptionally high IP3 using FEMPT transistors. He is also developing units for contesters. Contact owner Chris Moulding. David G3UNA /G6CP -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Rune Øye Sent: 13

Re: Topband: Air Wound Coil

If you don't have plastic pipe, select a plastic beaker from the kitchen cupboard. David G3UNA-G6CP -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Don Kirk Sent: 30 August 2018 12:53 To: Tim Shoppa Cc: Trevor; topband Subject: Re: Topband: Air Wound

Re: Topband: WB6RSE Flag type loop question

tnx I'll look at that David G3UNA From: Carl Luetzelschwab [mailto:carlluetzelsch...@gmail.com] Sent: 02 August 2018 12:29 To: David Cutter Cc: Joe Subich, W4TV; topBand List Subject: Re: Topband: WB6RSE Flag type loop question David, The NEC-4.2 engine appears to give very good

Re: Topband: WB6RSE Flag type loop question

I am at a loss to know how to model it with any confidence, for wires close to or on the ground. David G3UNA -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Carl Luetzelschwab Sent: 01 August 2018 23:02 To: Joe Subich, W4TV; topBand List Subject: Re:

Re: Topband: Effect of Ground on a Dipole

Roger I wondered if you'd considered the inverted L with a folded counterpoise ala K2AV. I'm seriously considering this with the 80m option for my very limited garden and another site. When doing your comparisons, do you use the RBN? Sorry, can't comment on your soil conductivity query.

Re: Topband: Effect of Ground on a Dipole

>From what I have read on K2AV, avoiding foliage is extremely useful. BTW Mike, G4IUF has only ever used dipoles (very bent and much lower than yours) on 160 and 80 and has done well with both, then again, he's been chasing dx for 25 years or so to accumulate his scores. David G3UNA

Re: Topband: Bury beverage wire?

There is an item in an old ARRL antenna book showing an 80m dipole residing in clay pipes just under the surface. David G3UNA - Original Message - From: "Dick Grolleman" To: Sent: Wednesday, January 10, 2018 6:09 PM Subject: Re: Topband:

Re: Topband: Detuning Relay Flyback Diode

From a relay hold-on point of view, this will perform very similarly to the diode across the relay. David G3UNA - Original Message - From: "Brian Pease" To: Sent: Sunday, December 24, 2017 5:18 PM Subject: Re: Topband: Detuning

Re: Topband: Detuning Relay Flyback Diode

Jim I agree with your idea about the zener and a diode but I disagree about using signal diodes on their own. In my early career I recall changing a few 1N4148/1N914s on small cradle relays. Changing to 1N4000 series stopped the failures. I also agree, that for small relays there is no

Re: Topband: Detuning Relay Flyback Diode

The back emf diode slows the relay a lot and you can improve that with a resistor in series, fudge as required. Here's another method: in the drive transistor circuit, fit a small capacitor between collector and base. As the back emf builds up, a current will be fed back to the base which

Re: Topband: Any recommendation for vertical

Elan I see from your QRZ page that you already have several towers and Yagi. Have you considered using one as a top-loaded vertical? Do a Google search. David G3UNA - Original Message - From: "Elan Paim" To: "Topband" Sent:

Re: Topband: Vac relay keying

Trevor That circuit works well if you only have a 13V typical radio supply. You can string several relays from the T/R line but remember to fit a 1N4000 type diode across the relay, + end to supply, -end to the T/R line. It's important to take into account your linear amplifier (if you are

Topband: future of ham radio: planting seeds for new recruits

Having just done another weekend of Jamboree On The Air, I'd like to suggest that presenting several modes at an event such as this is the way to go. None of the scouts had any history of amateur radio and didn't know what to expect, but they saw the wires we strung up and they had first hand

Re: Topband: RF choke/balun

To get the best performance from your choke, K9YC recommends you make a coil of about 7" diameter from memory. His document has lots of curves to choose the best assembly. David G3UNA - Original Message - From: "MR TREVOR DUNNE" To: "topband List"

Re: Topband: Short Verticals

As I understand it, if you reduce the effect of ground loss by using raised radials you should get a more predictable and consistent result. So, your main radiator, the vertical, sits between 2 sets of radials, one set at the top and one at the bottom. My feeling is that this gets the most

Re: Topband: 160 m inverted L

testing.com] On Behalf Of David Cutter Sent: Mittwoch, 9. November 2016 17:37 To: Mike Waters; Rob Atkinson; topband Subject: Re: Topband: 160 m inverted L I recall reading from Ralph Holland that 0.015 wavelength was a good height. David G3UNA - Original Message - From: "Mike

Re: Topband: 160 m inverted L

I recall reading from Ralph Holland that 0.015 wavelength was a good height. David G3UNA - Original Message - From: "Mike Waters" To: "Rob Atkinson" ; "topband" Sent: Wednesday, November 09, 2016 4:11 PM Subject:

Re: Topband: Traditional or off-center fed 160m vertical design?

Have a look at this idea: http://www.m0rzf.co.uk/ants1/ This is an off centre fed but your normal feeder is connected to the end of the antenna via a choke. I've made several of the 40m version and 3 using double the sizes for 80m. I used simpler chokes for both and measured common mode

Re: Topband: New Noise - 160 Meters

Petr That's very interesting. I have heard that long led strips eg in the kitchen are powered from a noisy smpsu: the long cable is the antenna. A linear supply should stop that noise or small ferrite toroids (it's very low current). I have just purchased some from IKEA and will be testing

Re: Topband: 80m rotatable dipole load coil questions

A quick note on a protective coating for aluminium: You might like to look at Alocrom 1200 (Alodine 1200 outside Europe) which can be hand-applied to preserve and protect aluminium from corrosion, retaining its conductivity. I used it for many years in industrial and military applications,