A Woman’s Prerogative

June 19, 2016 4 comments

I was originally going to archive this blog and made an announcement that it would not be updated any longer. Then I changed my mind. I am sorry to say that many of the older posts have lost YouTube content due to me deleting my YouTube account. I could not bear to see myself, such is the nature of gender disphoria.

I have now decided that this blog should become my own again. I changed the  name of the blog to match my new callsign. There is not much I can do to change the old posts to match my affirmed gender nor my new name.

I have moved from acreage in a regional city to a one bedroom apartment in Australia’s largest city. My partner and I lost our business, almost all of our possessions and personal wealth due to my depression, anxiety and panic attacks due to gender disphoria. My new location, housing arrangements and budget mean that I will not have the impressive station that I once had. I will have to find new ways to operate and new interests within amateur radio.

For those of you still interested in what I post, thank you.

(I have since moved to Gunnedah NSW where I can pursue my gliding goals)

Kimberly  VK2KMI/VK4KIM ex VK4MDX

What Purpose the Zero Ohm Resistor?  ICOM IC-703 Antenna Socket

March 24, 2021 Leave a comment

“Always walk through life as though you have something new to learn, and you will.”

Due to delays waiting for parts for my Ameritron AL811 project, I decided to start on another repair job that has been awaiting my attention. Last time I used my Icom IC-703 there was no power out on transmit. I suspected blown finals- that will be a painful repair job with SMDs! But today when I attempted to power it up, it was completely dead. I opened it up and checked the internal fuse; it was intact. I checked the rectifier diode a DSA3A1. It was dead. Hmm Why a rectifier diode on a dc supply? I guess it is normal to use these where there may be a fairly decent current (direct connection to a car battery for example) and to provide reverse polarity protection from that current.

So OK but why no transmit when it was powering up? A closer look revealed a little teeny resistor that runs from a track on the PCB, to the centre of the antenna socket has come away from the PCB. It had broken off and left the tail embedded in the board. This thing was tiny! I had to desolder the antenna socket anyway, to get access to the bottom of the board, to remove the diode, so I set about doing that and flipping the board. That is when I saw this tiny resistor. It had no coloured bands at all but it looked to me to be a resistor. I searched the Icom Service Manual and found it on the PCB drawing, labelled W999. The table of components told me it was generally referred to as a Jumper ERD-S2T0. Searching this info online I found that it referred to a zero ohm resistor. Now that got me really thinking. What possible purpose could be served by a zero ohm resistor? Why not just a short wire?

The answer may well not surprise you, it didn’t me. The answer is speed, time and cost in manufacturing, especially if that manufacturing is done in part or completely by robotics. The part has no electronic purpose.

Categories: Daily News, HF

About that Plate Choke

March 24, 2021 Leave a comment

For those who don’f follow my Twitter, here are a few comments about the AL-811 plate choke that I made on there.

Categories: Daily News

Does anyone else miss the original Dick Smith Stores and similar?

March 24, 2021 Leave a comment

I remember in the 1970’s the heyday of CB radio, when I’d walk into the local Dick Smith Store and find just about any component I wanted. I also could see, on the shelf, equipment I aspired to own but could not afford. Online shopping and cheap electronics from China, have pretty much destroyed that particular market. Yes I can get some components from Jaycar thankfully but like the other stores, the range is getting more and more limited as the shelves fill with cheap (throw-away) electronic gadgets.

As I work through the repair of my vintage radios and amplifier, I am slowly building a tally of items that are almost impossible to purchase, have to be purchased in quantity from afar, or outright unobtanium. High voltage capacitors of specific values being one such example e.g. 360pF 1000V. Even if I search for options like two capacitors in series or two capacitors in parallel, it is impossible to reach the right values with what is available for less than the cost of a small motor vehicle.

  • Plate choke for an Ameritron AL811- temporarily unobtanium (RF parts and DXEngineering and others)
  • the aforementioned 360pF 1000V capacitor ( i can get some if I spend $35 plus shipping)

I even had trouble getting PCB mount 20mm x 5mm fuse holders, 8amp slow blow fuses and 15 Ohm 10W resistors locally.

I’m not convinced that online shopping is always convenient.

What about you?

Categories: Daily News, Home Brew

SWR, Valve Flash-overs, Antenna Position and RF in the Shack: It’s not always what it seems

March 21, 2021 Leave a comment

If you have been following my posts, you will know that I’ve been working on an Ameritron AL811 which recently experienced a flash-over and took out the Plate Choke among other things. Now, with this amplifier and 811 valves, many would be quick to point the finger at the poor old 811 weaklings, but that may not be fair. So here is a little more context-

I recently moved out of the city to a regional town and finally was able to play amateur radio again. I had room for antennas and I was away from the horrible QRM of the city. Unfortunately my block has few trees to hang antennas from and I had zero funds, so I cobbled together the only antenna I could from the bits and pieces I had, a nested Marconi- See previous post. The antenna performs beautifully once I spent a bit of time getting the element lengths and counterpoise length, height and insulation correct. It was resonant on most of the 80m band, some of the 160m band and all other bands bar 30 m. But you wouldn’t know that from my LDG AT-1000ProII.

Don’t get me wrong. I am not knocking the LDG tuner, it’s a great bit of kit, but it is known to suffer in extreme circumstances from RF interfering with the microprocessor, thus display incorrect SWR indications on the LED bar. This was the case for me, as I always checked SWR with my Diamond SX100, which despite the name is good for 3 kW. The tuner was not really needed, as I could mostly keep it bypassed, because I had good SWR on all frequencies I used. But as I would find out, there is a catch.

When I’d installed the antenna, the existing high point to which I could attach the 80m leg was directly overhead the shack immediately above the point where the coax entered the room. Literally within meters of the radio. This of course meant that with the amp running, on 80, even without it running, I was getting RF into the shack, not via high SWR or high feedpoint impedance, just pure good old radio waves. Now of course the valves in the amp don’t really care how the RF get’s into them, they just know how to complain when it does.

So today I moved the antenna. It took a bit of work as I had to relocate the weather station and fit a mast to the bargeboard, but I got it done. Now I await the parts for the amplifier. The RF choke could be easily rewound but the replacement part is $30. I’ll have a go at rewinding it, at some later date. Beware overlaps in this choke, that may have contributed to the early failure. Ameritron skimped on the varnish, so many of these have loose windings that droop down and overlap the windings at the top. This WILL lead to a failure eventually.

So whatever you do, keep the RF out of the shack, even if it isn’t coming back along the feedline 🙂

73 de VK2KMI

Categories: Daily News, HF

Ameritron AL-811 Repair: Plan of Works

March 15, 2021 Leave a comment

For an introduction to this , go to my previous post Ameritron AL-811 Purchase and Repair

WARNING: LINEAR AMPLIFIERS CAN RETAIN LETHAL VOLTAGES EVEN WHEN TURN OFF AND UNPLUGGED- YOU HAVE BEEN WARNED

THE HISTORY:

I purchased an Ameriton AL-811 that was in lovely shape cosmetically but seemed to have some issues.

Shortly after my first use, it blew a hole in the side of an 811a. This valve blew while using on 80m. Afterwards, I required a setting of zero load which leads me to think a I have a failed padding capacitor. I have several on order and will test the old ones soon.

Downstream affects of this or possibly other events in the amplifier’s past seem to be

  1. overheating of parasitic suppressor board leading to detachment of braid to tube cap- re-soldered and board components tested fine despite evidence of overheating. This board has the new 5 turn inductors to reduce overheating.
  2. confirmed damaged plate choke 9arc). needs replacement or rewinding
  3. possible leaky ALC isolation capacitor- I have one on order
  4. damaged blocking capacitor- I have two 15kV units on order
  5. possible meter shunt resistors (330 ohm and 180 ohm specified) are undervalue. Metal Film Resistors tend to go low when overheated. This is due to the manufacturing process which can lead to resistors becoming semi-conductors due to overheating altering their makeup. – I have replacements ready to put in 1/2watt replacing 1/4 watt

One other small issue, one of the riv-nuts (captive nut) that holds the upper cover on is detached.

Categories: Uncategorized

Ameritron AL-811 Purchase and Repair

March 12, 2021 1 comment

WARNING: LINEAR AMPLIFIERS CAN RETAIN LETHAL VOLTAGES EVEN WHEN TURN OFF AND UNPLUGGED- YOU HAVE BEEN WARNED

Recently I purchased an Ameritron AL-811 amplifier. This is the 3x811A setup which Ameritron claims is good for 600 watts PEP. I think that is stretching things but that’s a whole different write up for another day. This one was in beautiful condition but appeared to have some issues that led to the destruction of an 811A valve (we don’t call them tubes here in VK) when I was using it on 80m. It also blew the D16 diode which I replaced.

I was pretty new to this amp but know the specifications of the components pretty well. I suspected a padding cap had failed. I find now that on 80m the load is at zero for best power and that amounts to less than 300 watts. Load at zero is never a good thing. So I now have ordered several replacements, there are two used on the 160 and 80m bands. For now I am staying off 80m. The amp is working beautifully and has allowed me to make some great DX contacts from my new QTH including a new DXCC Montserrat. The nested Marconi seems to be a great antenna too. I may just keep it. 🙂

I’m really looking forward to using this amp on AM with the Johnson Viking Ranger II. Many people claim that the amp isn’t good for AM, but that simply isn’t true in my view. At 100 w carrier, my legal limit for AM, I can run it on 40 metres with 180 mA of plate current. The max specification for high duty cycle modes is 400 mA. Of course, to use it with the Viking Ranger II, I’ll need a 6dB attenuator which is on order. I may even need the attenuator to be 10dB, we’ll see.

When the caps arrive, I’ll replace the 80m cap and see how we go on 80m. I also have three 572B’s on order, as this amp will ultimately be changed over to those, once I have the bugs ironed out. They are much more robust, but if there are faults, I’ll kill them too, and I really don’t want to fry $350 worth of Chinese glass.

73 VK2KMI

Categories: Uncategorized

Viking Ranger II Restoration

March 11, 2021 Leave a comment

If you have been following my Twitter (see the bar on the right), you will know that I have been restoring a Johnson Viking Ranger II. As many hams know, my life went into a big spiral when my business and marriage collapsed. I ended up homeless. Eventually I moved to Sydney and started all over again. I had however saved some of my favourite radio projects and kept them in storage. One of them was a Johnson Viking Ranger II. It was in beautiful condition but more recently something has damaged the paint in a few places. I suspect something was spilled on it in storage. Electrically it needed some work. I had replaced the audio driver transformer but since doing so the rig had been in storage and I wasn’t sure if I had finished that job, or what other work was required or undertaken all those years ago, so it was quite a bit of work to get it sorted. I also had to restore n Astatic D104 on a TUG-8 stand.

I am very happy to have this radio going as it is AM and CW only, two of my favourite modes. I am looking forward to getting the new 811 valves (tubes) and eventually the new 572bs for my Ameritron AL-811 so that I can operate with full legal power on AM.

I look forward to many CW and AM contacts on this rig. If you too are interested in old rigs and AM, check out the Ancient Modulators Club of Australia on Facebook.

Categories: Uncategorized

My Nested Marconi- Ugly but Effective Multi-band Antenna

March 6, 2021 1 comment

Back in 2013 I suffered a massive financial loss. I ended up homeless after running a successful business and owning two properties, one on acreage, where I could have pretty much any antennas I wanted. Despite all that room, my partner was keen that i didn’t cover the whole yard in antennas, so apart from my 160m loop, and an 80m delta loop, my favourite antenna was a ZS6BKW, I had two of them.

Later when I moved to Sydney, I kept a ZS6BKW in storage but never had the room to install it. Somewhere along the way it got lost. At some point I hastily constructed a random length dipole for SOTA and VKFF (WFF) and by the time I got around to looking at it for use at my new QTH, I had cut some of the 450 ohm ladder line off it, leaving it with just 9 or so meters of ladder line, which unfortunately does not correspond to any dipole design. I also had no poles to hand a dipole from. I could attach a pool cleaning wand to an existing TV antenna mount on the house and I had a 12m squid pole. So it was that I started searching for an antenna design that I could build with my scrap pieces of wire and the squid pole- enter the Nested Marconi.

The Nested Marconi design could be build with just 7.5 m of 450 ohm ladder line and would require no more wire than I had in my possession. I could attach the centre to the 12m squid pole, the short horizontal to a tree and the long horizontal to the pool cleaning pole mounted on the house. All attachments would be done with 150 pound fishing line. I added a 20m and 10 m element too. Next write up, I’ll tell you all about what you may encounter if you decide to build one and I”l show the photos of just how ugly it is :-). It would not be difficult with a better set up to make it more attractive 🙂

Categories: Daily News, HF, Home Brew

Valves/Tubes – What will we do in the future?

February 22, 2021 2 comments

For some time now, I and many like me have been restoring older radios using NOS (New Old Stock) valves, what you Americans call tubes. Tubes here contain beer, not cathodes and anodes and screens and grids in an absence of air. Recently I had an 811a valve/tube fail in my Ameritron Al-811. The failed item was a Matchlett which frankly I think are no different to any of the other Chinese made valves available today, so I ordered some Shuaguan 811’a from China.

As is often the case with my little online automotive and small engine parts business, the Chinese supplier turned out to be a reseller more hopeful about sales than actually equipped to proved sales. I cancelled the order and sought a new supplier. Sure I can buy Matchletts online from the USA if I want to pay $150 postage on top of the purchase price,. I’m at least likely to get them, but I’d get 572bs from China for the same price. Which is my next order. The Ameritron AL-811 works better with 572bs anyway, so my next order will be those. I just need to be sure the recently bought amp has no further issues before I stick $350 worth of Chinese glass in it. Oh for the old days.

Categories: Daily News, HF

Some Days are Diamonds some are Polished T*rds

February 4, 2021 Leave a comment

This morning (Friday) before work commenced, I thought I’d get a head start on my planned weekend activities- that of antenna building. A few days ago, I had dug my MFJ antenna analyser out of a box and checked that it worked, added some new batteries and did some testing of some items.

Today I started organising the bits I needed including the wire for the 80/40 trapped vertical. I thought before my daily stand-up started, I’d quickly test it using the analyser, so that when I got around to building a new ZS6BKW, I’d have the necessary test equipment ready to go. You guessed it! The antenna analyser that has given me faithful service for decades decided to quit.

Update after partial disassembly and cleaning of the PC board it is working again

Categories: Daily News