Home brew

[VK6ZMS]

Nothing like a bit of flash-over to kick start the day.

btw
Nice antenna if you were using yesterday I had a strong signal on your input at my QTH.

[robbage]

That's how I get the extra gain

[robbage]

Nice antenna if you were using yesterday I had a strong signal on your input at my QTH.

I was home on the 1/4. I seem to be in a good location here; nice and flat. About 9 or 10k N.E. from yours. I didn't think to reverse you, but you were clean as.. the audio was down a bit though. Hope to have the 5/8th up on the mast at work on Tuesday. The 1/4 there isn't doing much. Too many trees and powerlines. They're bumping the HV from 11kV to 22kV next year as well

[Zebedee]

Nice pics!

[Tyranus]

It was bloody windy the last couple of days.

Let's face it, with you're prime pristine location looking out over the ocean, it'll be bloody windy every day. Though some maybe a bit more than others :p Make sure you take your kit down when storms are forecast though, it'd suck to rock up to work on monday to find it in 2

[robbage]

It was bloody windy the last couple of days.

Let's face it, with you're prime pristine location looking out over the ocean, it'll be bloody windy every day. Though some maybe a bit more than others :p Make sure you take your kit down when storms are forecast though, it'd suck to rock up to work on monday to find it in 2

That test stand is just for testing... you need to get some height and clearance otherwise it messes with SWR. It goes back in the shed before somebody pinches it. (yep it happens even there..). If the antenna itself can't handle the wind then I fail anyway. See how it goes 8 - 10 metres higher up! It is a nice view though. Rotto looks awesome some nights.

[Tyranus]

Yeah rub it in, I look up from my desk and I see other desks and windows, I look right and I see 2 people and the tops of buildings in Midland. When you're operating and you look up from that dodgy white thing you see ocean and rotto and...jealous

[robbage]

Testing on the mast. 1.3:1 on RLMs freq

[robbage]

Here's some pics of my completed battery pack thingo for running a mobile radio portable. They're pretty large.

Almost complete. The box is steel and waterproof. It can also withstand a bit of violence. The lid is removeable and has a handle. I'm using 4 x 12v/7Ah SLABs (an example one in the background). There is a 1A charger (sort of visible below the terminal block). The black thing wired to the smaller terminal block is a resettable 25A breaker. Should be able to run a 100w rig


A closer view of the wiring and breaker. The charger is easier to see.


Done. Collapsible handle visible. The DC cable is 25A with a 20A quick-connect connector that I have installed on both my mobile radios, some portable lights, a radio and a TV. There is a low current DC cable for voltage monitoring or what-ever. I also have a lighter lead so it can be charged in the car. Just needs a couple of coats of paint.


I'm working on a heavy duty non-portable one as well, which takes up to 16 of those batteries and (with a bit of luck) will charge from solar and/or wind as well.

[Tyranus]

cool! Looks like an interesting little project!

[Zebedee]

Nice one Rob!

So you're into a bit of project work then???

[robbage]

Nice one Rob!

So you're into a bit of project work then???

Yeah, always got a few projects in various stages of construction. Some even get completed

[VK6ZMS]

I will be interested to see the performance on SSB 100 watts.
My FT 857 in the car starts dropping the power as the volts drop below 12.5 .
I now have the engine running whilst T/Xing to keep it at 13.8.

[robbage]

Yes, will be interesting to see what happens. Should be OK with 25 watts which is my max with my mobiles. There may be noise from the charger on HF as well. I've already planned remote switching of the charger when the rig is powered up, if that happens. Should be OK. It's not designed to be ideal.

[robbage]

I was going to send this to Zignig but it might be of interest to others. I have the rig in my car set up so it can't be powered up without the key switched to (at least) accessories. If you tend to leave the radio on and flatten the battery... might be handy. Also, because I spend quite a bit of time hopping in and out of the car and driving short distances I don't want the radio powering on and off every two minutes so I came up with this. I also need to push a button for power. This could also be handy if you have a company vehicle and others might drive the car. Put the push-button in an obscure place or disguise it.

Sorry about the dimensions; I forgot to scale it down.



You shouldn't wire the radio straight to the ignition switch so you need to switch the power with a relay.

In this diagram, the existing wiring is between the battery and the radio including the fuses at the battery and one at the radio. I strongly advise not having anything less than this. The positive line is severed and wired to the normally open contacts of the relay. I used two sets of contacts because the relay I used is 16A per contact and I may end up with a 100w radio in there one day. One set of 16A contacts is OK for a 50W rig. The relay you use requires another set of contacts for this arrangement. That set is used to latch the relay.

In this circuit with the ignition off, the relay is off and nothing happens. Turn the key to ignition, nothing happens. Press the pushbutton (the one at the bottom that I forgot to label) and the relay actuates. The bottom set of contacts then applies voltage to the coil causing the relay to latch (ie it powers itself) The radio should power up. Both my mobile rigs return to their last powered state when power is applied which is handy. When you turn the ignition off, power is removed from the relay and everthing shuts down.
The relay I used is one designed to switch 3 phase and is one of a bunch I had left over at work when the equipment was upgraded. An equivalent from RS is about $15. You can use an automotive relay if you can find one with at least two sets of contacts rated for the current.
The diode is to prevent the Back EMF spike that coils produce when they relax. I also wired a panel LED across the coil and mounted it on the dash so I can see that it has worked. If you want the rig to come on without pressing a button then leave the button out, leave the bottom set of contacts out and wire the accessories line straight to the top of the coil.

If you haven't got fuses at the battery, make sure this assembly is well insulated because a short to the chassis will probably cause a fire. Make sure you have fuses at the battery OK?