Spider Antenna – Circa 1985

On the heels of the Wolf River Coil DIY tripod rebuild, comes the Spider Antenna. Invented and patented at the time by Fred Smitka, K6AQI, out of California, the Spider Antenna was created and sold in the early 80’s. It is by design a mobile antenna designed to take advantage of the ground plane a vehicle can provide. But since I had just reworked my tripod for the WRC, I made a few adjustments so that I could also connect the Spider Antenna and take advantage of the radials I had already created for the WRC. And it works! Sort of. More on that in a moment…

Where the WRC is a bottom loaded vertical, the Spider Antenna is a top loaded vertical. This blast from the past was picked up in a Craigslist buy several years ago. I was looking to upgrade a dipole from my then G5RV Jr. When I arrived to purchase a DC-CC fan dipole I was greeted with a pile of various antennas. There were a couple of wire dipoles, a rigid Cushcraft D3 20-15-10 rotatable dipole, what looked like at least a pair of “chimney sweep” MFJ antennas with all manner of missing parts, and maybe one other antenna worth of parts I never did figure out. But, there was also a cardboard tube that contained this odd looking antenna system that is known as a Spider Antenna. The seller was more than happy to see the entire pile leave. Their trash became my treasure.

So what is this thing? In simple terms, the Spider antenna is a top loaded vertical. Unlike the coil antennas we are accustomed to seeing, where you have 1 coil, and then you tap the coil for the band you wish to operate on, the Spider Antenna has a 5′ metal mast, with a fitting at the top for up to 4 individual coils. There is a separate coil for each band. The coils come in bands 80-10. The one catch is that 80, and 40, can only go on top. So you cannot for instance have 40 and 80 on at the same time. But you could do 40, 20, 17, and 15 if you like, or whatever combo you wish. What was really cool about this find was that it was a complete set of coils for 80-10 meters. bands!

To tune the antenna, over each coil is a ferrite that you slide up or down the coil until it is resonant where you want it within the band. As the bandwidth can be a bit narrow on 40/80, you will have to adjust to which end of the band. What is also remarkable is that after 36 years, this antenna still seems just fine. The antenna is rated to easily be able to handle 200 watts. And I even found a review online from Gordan West that claims he ran a Magnus 800 watt amplifier through the Spider Antenna and it worked just fine.

The entire antenna is of quite high quality construction. Normally, as we have experienced, plastic coatings break down over time. The materials on the Spider Antenna have held up very well. Each coil is of rigid fiberglass construction.

Setting it up in the back yard and using my Nano VNA, I was able to bring adjust each coil in just a few minutes. I hooked up my KX3, but was only on battery so output power was quite low, but I was able to receive quite well. I will have to connect to the TS-440 and do an A/B test and post an update.

Son of “LancePod”

A couple years ago now, our local craft person, Jonathon, W6BID put together a club build for a tripod for the Wolf River Coils SB1000. The WRC TIA (Take It Along) kit t is an excellent, economical, portable, base loaded, vertical for pretty much any band. The community around this antenna has spawned all manner of modifications, whip options, radial options, and in this case a DIY tripod. The “out of the box” tripod, while mostly adequate, was tippy in windy conditions. Several of us have also adopted either the MFJ-1979 or Chameleon SS-17 stainless steel whips for better performance on the lower bands. The problem being with the longer, larger whip, the base needs more stability. Enter W6BID…

For a club meet, W6BID organized kits for us to assemble in a weekend garage project. Each of us taking turns drilling holes, and assembling our new WRC tripods. The original kit consisted of a piece of plate steel, a 3/8″ thru-hole, stainless steel antenna mount, 6 L brackets that Jonathon had welded to the plate ahead of time, 3 sections of 1/2″ steel square tubing, and some bolts here and there. All that and a quick coat of spray paint resulted in one stout tripod base. It has served us well!

But some issues crept in over time and after multiple uses. For starters, this thing is chonky! And secondarily, since the plate is steel, oxidation formed in between the plate and the stainless steel antenna mount creating resistance with the radials. This was finally identified as to why SWR readings were so out of whack from when the last time it was used.

So back in the shop it went for an update.

To address the chonk, I drilled holes down each of the 3 legs at 3/4″ intervals, and then turned the leg 90 degrees, and repeated at offset 3/4″ intervals. The end caps which had fallen off long ago, were replaced, but this time filled with hot glue before being re-attached. The base metal plate also had large holes drilled where I could safely remove material. This reduced the weight considerably, but still providing a solid stable base for the antenna.

To solve the oxidation issue I used a product called DeoxIT L260Cp that is a lithium grease that is infused with copper particles. Once the steel surface was cleaned back down to bare metal, a dap was applied to the surface and everything reassembled. Other changes made along the way…

  • Much experimentation with radials
    • Out of the box are 3 33′ radials made of black silicone coated wire.
      • Pro – Fairly quick to roll out.
      • Con – Performance was “Ok”.
    • Doubled to 6 33′ radials
      • Pro – Increased performance significantly
      • Con – When out in the field, you are taking up a circle nearly 70′ across. When camping this is valuable site space. The black wire was hard to see in the grass. Gopher/ground hogs actually tried to drag radials down one of their holes one night at a camp site.
    • Swapped out wire radials for 33′ tape measures
      • Pro – Fast to deploy. Easy to change the length if you want to “tune” the length for the band. Super fast to roll back up. Bright yellow tape is easy to see when deployed so people are less likely to walk through your radials.
      • Con – They rust. They are heavy. They are bulky.
    • Swapped out tape measures for 9 8′ radials constructed from a bright yellow silicone wire, and added quick disconnects.
      • Pro – Very fast to deploy. Bright yellow for visibility when camping or portable. Shorter length is way way less prone to tangling. Very lightweight. Compact. Works just as well as the 6 33′ radials.
      • Con – Not quite as efficient on 40 or 80 meters, but is still below 2:1.

Overall this has been a great project that has now gone through a couple iterations resulting in a very portable HF antenna solution that has performed exceptionally well. I just recently also picked up a padded tripod bag to store it in, and have a 50′ length of ABR Industies ABR240-UF (Ultra Flexible), with 5 ferrite beads shrink wrapped to the end. This entire solution can be in place in moments, is easy to tune, and with the larger SS17 whip is an efficient antenna system.

A Few of My Favorite Things–Part 1

With apologies to Julie Andrews, I thought I’d share a few favorites that I’ve bought at least once on Amazon. Many are ham-related, but certainly not all. I buy stuff on Amazon fairly frequently, to the point where they now have a Prime van parked 24/7 in front of my house. Fairly frequently. I said that. We take food out to the driver occasionally and let her use the bathroom. We’re not uncivilized people.

I’m a fan of noise-cancelling headphones. I bought the very first wired model that Bose produced way back when. They have lots of competition today. Since last year, my new favs have been the wireless Sony WH1000XM3 Bluetooth headphones with built-in mike for Alexa or mobile-phoning. I got the silver model (hey, everybody does black!), and they are wonderful to wear. Excellent sound for all kinds of music, comfortable over-the-ear cushions, and very easy to use.

If you don’t like the over-the-ear style, then quit reading now, because I like them to cover my ears completely so all the conversations and jet-engine whooshing noises can be reduced to near-zero. I hate sticking earbuds directly into my ear canals (I think I ruined them with the wax pellets that they handed out when I flew in the USAF), and the “open” style of noise-cancelling headphones appear to me to be as useful as screen doors on a submarine.

I was going to say that this is not a ham-related item, but I’ve been experimenting with connecting them to my Elecraft K3s transceiver, and I have to say that I think they are a winner for short-wave listening. I use an external Bluetooth transmitter connected to one of the K3’s audio outputs, and I can walk around and listen, still fiddling with other things in my shack. If you buy a Bluetooth transmitter for ham use, make sure to get one that does the new low-latency audio, which the Sony supports very well. Cuts the normal BT audio delay down to less than 40 milliseconds.

The only real downside to them is that they are $350. As my dad might say, “You’ve really got to be madly in love with something to pay that kind of money!” Yeah, tell me about it. But I travel a lot, and these are the best for that activity, hands down. Just don’t ask me what the pilot told us.

But it turns out that I also want something cheaper that I can use in the wood shop, doing something dusty or messy, or just something to knock around without worrying about the cost of replacement. I found this pair of headphones that do just about everything the expensive Sony headphones can do, but at a super-low price!

And the winner is the Anker Soundcore headphones, and they are only $59.95 on Amazon. They are not perfect copies of the Sony, performance-wise, but they have a decent quality feel, and are certainly an excellent deal for the price. I’ve been very happy with them, and recommend them without reservation. Now I’ll list a few good and less-good points. Oh, you might call them reservations, I guess.

Pros:

  • Very good sound with very decent bass (one of my requirements). Capable to doing the official Bluetooth HD mode for hi-res audio, like the Sony.
  • About as comfortable as the Sony and look just about like them, with decent fit and finish
  • Easy-to-use controls
  • They’ve screen printed a big “L” and “R” on the inside of the left and right earcups, respectively. A nice touch for us reading-glasses-for-everything-smallish types.
  • Built-in rechargeable lithium battery like Sony, with long listening time (claim is 40 hours and I have no reason to doubt this). Uses a micro-USB charging jack. The Sony uses a USB3 connector.
  • Has a built-in mike so you can use them with a mobile phone, again just like the Sony model.
  • Can be paired with more than one thing at a time. You can only use one audio stream at a time, of course, but you can have them paired with, say, your computer and your mobile phone. If you have Windows on your computer, be aware that Windows will occasionally try and “steal” the connection back, but this is a stupid, freaking, idiotic, %&@#*!($% Windows shortcoming, not the fault of either pair of headphones. Everyone else on the planet has figured out how to make their operating system work reasonably well with Bluetooth except Microsoft! This from the people who are still trying to destroy your computer with stupid, freaking, idiotic, poorly-tested updates to Windows 10 in 2020! What? Oh, OK, I’ll wipe my brow and sit down again. Sorry, they just really hack me off, as the British like to say.

Cons:

  • The Sony can do a new type of low-latency Bluetooth streaming that I mentioned earlier, which you’ll only care about if you watch TV or play fast-action games with the headphones on. This Anker model is missing that feature. You may never notice it, though.
  • With the ANC (active noise cancelling) turned on, the Anker will occasionally emit a loud “POP” from both earpieces if you are chewing crunchy food (yes, I’m not kidding!), or you sneeze or cough loudly. This is a minor annoyance, but still annoying. Maybe it’s just a quirk in the pair I own, but you’ve been warned.
  • Lacks the Sony fun touch-surface controls that allow you to turn the volume up and down, pause, answer the phone, etc. You can still do all these things, but the Anker uses little discrete buttons or rocker switches rather than the iPhone-like touch surface of the Sony. Not a deal-breaker by any means, and if you remind yourself you’ve got an extra $300 in your pocket, you’ll definitely never miss the feature.

OK, so there you go. I’ve saved you some dough, got to rag on Microsoft again, and I’ll add some more favorites as time permits.

73 and good listening,

Dave – K7DAA

Get on 40 meters SSB voice for $59

http://www.hfsigs.com
The BitX40 “you finish it” kit for $59

On tonight’s net, I mentioned that you can get on 40 meters for under $60, and without the need to be a virtuoso on the soldering iron or know tons about radios.  Say hello to the BitX40, an almost completely-finished 7 watt transceiver.  All you need to do is supply a box or case of some sort to put it in, a battery, and an antenna.  Everything else is already there for you.  To finish it, you solder on wires to a few controls, the battery (or 12 volt power supply), the antenna connector, and you’re ready to get on the air.

The BitX series of radios have an interesting back story.  A ham in India named Ashhar Farhan, VU2ESE, was concerned about how low the number of hams there were in his country, as well as other third-world countries.  After pondering this issue for a bit, he decided that one of the greatest problems a prospective ham faced was the high cost of even used ham equipment there.  He set out to make a 20 meter voice transceiver that used less than $20 in materials.  Thus was born the BitX20 about 10 years ago.  He cut costs in some very innovative ways.  For example, instead of the relatively-expensive ferrite toroids that are often used in radios, he substituted fiber or metal washers and wound his coils on them instead.  He decided to limit the power output to less than 10 watts so that a very common power MOSFET transistor could be used.  He also designed a novel main VFO tuning system made from a plastic drinking straw and a coil of wire.  I have one of these original (slightly improved) kits.

About 6 months ago, Ashar decided to try and help employ women in India to make a radio that might sell in higher quantities if he made it easier to build, but still supplied a quality product.  He created the BitX40, and founded a new small business to support it.  This is what I have in a my hands today, and I have to say that it is a very high-quality product, and he’s made it very easy to complete.

Gone is the drinking straw VFO, replaced by a very cool “Radiuino” board.  It is a very hackable Arduino that drives a 2-line LCD display and a DDS chip that outputs a highly-accurate, clean RF signal.  This one item alone increases the “fun factor” quite a bit, and helps contribute to a feeling that you are using a high-quality product that you yourself completed and mounted in your own custom housing.  Mount the display face and knobs to a plastic or metal ammo can and throw in a small battery pack, or put it in a cigar box (do they still have those?), or make your own custom wood enclosure.  It’s all up to you.

I suggest you give this cutie a try.  It’s not very intimidating, you’ll be very pleased with the results, and you’ll be helping some folks in India become more self-supporting.  You can find his website and ordering info here:  http://www.hfsigs.com/

 

 

Super PowerGate: Part of a Ham’s Home UPS

During our tech net tonight, I couldn’t remember the name or model number of the piece of gear that allows me to have my own uninterruptible power supply (or UPS) to keep all my ham gear running, especially when the lights go off.  So here it is:  The West Mountan Radio PG-40S PowerGate.

Along with a decent-sized deep cycle 12 volt battery (1 or more in parallel) and a 13.8 volt power supply, the PG-40S ties them together to give you uninterrupted power, and also keeps your battery charged, ready for action.  It can provide up to 10 amps charging current to the battery when the power comes back on.  It can handle up to 40 amps, or the equivalent of two fully-equipped HF 100 watt transceivers, or as many as four 50 watt-type VHF/UHF mobile radios.

I’ve had mine for years, and can say I wouldn’t have it any other way.  It’s silent, and the status LEDs on top tell you at a glance what is going on.  The connectors on top are Anderson PowerPoles, pretty much the standard 12 volt connectors in use by all of us these days.  Available at our local HRO stores or mail order.  Price is about $140.  Not cheap, but I can’t live without mine!  We also have this same unit in operation at the WB6ZVW repeater (442.500 MHz, + 5 MHz, 100 Hz PL) on Crystal Peak to handle its battery backup needs.  This one item kept us running without fail during last summer’s big Loma Prieta fire.

Items covered in our 1/4/17 Tech Net

In this week’s first-of-the-month Tech Net, we covered quite a wide range of Q’s and A’s, as well as some new and old laws on the books.

The first of those laws is the new California restriction on distracted driving and cell phone use that does not exempt holding an amateur radio mike or walkie talkie in your hand.  Nobody knows yet how this is going to play out, or if any hams are going to end up being pulled over.  Here is the paragraph taken from State Assembly Bill AB-1785 that defines what a “restricted device” is:

(f) For the purposes of this section, “electronic wireless communications device” includes, but is not limited to, a broadband personal communication device, a specialized mobile radio device, a handheld device or laptop computer with mobile data access, a pager, or a two-way messaging device.

I guess we would be caught under the “specialized mobile radio device”, but the wording, and even the definitions they provided, are so vague that I could probably be pulled over for talking into a corn dog.  And yes, they did exempt anyone operating as an emergency services person.

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Along this the above new law is a requirement that the restricted device be mounted to the dashboard.  One of our members reminded us of another law that is in effect that does not allow you to mount anything in the center of the dash, or on the low-center part of the windshield.  You must mount your GPS, phone, or whatever in either the right or left corner of the dash only.  The idea being that anything mounted in the center will obstruct your vision.

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Sugru is a neat, new product that just might find a use around your home or garage.  See it here:  http://www.sugru.com  It is a flexible, heat- and cold-resistant, grippy and moldable polymer that can do some pretty cool things.  After you mold it to the shape that you want, it remains flexible.  Easiest thing to do is to have a look on their website at the pictures and also videos that show some good ideas.  Aaron, W6TDR, brought it up and mentioned that he’s used it.  I have several sample kits of it, but I haven’t actually used it yet.  I also got a fun kit from them that includes some button magnets.  Oh boy!

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We talked briefly about using silicone grease (not silicon!) in RF connectors to displace water and to keep corrosion off of connector pins.  I am also reminded that I used a small tube of silicone grease on several rubber o-rings that I recently installed inside of my new water softener.  Avoid using silicone grease in very high-power RF, since you’ll get carbon tracking and flash-over, but for amateur power levels, that’s probably not a concern.  It is apparently OK to wipe silicone grease on the mating surfaces of RF connectors, and they will be protected from corrosion and presumably will wipe away from the points at which direct metal-to-metal contact needs to be made.  Remember that we are talking about SILICONE the polymer, not SILICON the soft metal that bursts into flames when exposed to a little moisture.  People constantly confuse the two in everyday speech.  Even those that should know better.  If you are ever having trouble remembering which is which, please refer to the “Rule of Two Valleys”:

1. SF Bay Area and Tech Capitol of the World:  Silicon Valley

2. Hollywood, full of “enhanced” actresses:  Silicone Valley

You’re welcome.

See here for further info:

https://www.w8ji.com/dielectric_grease_vs_conductive_grease.htm

http://lists.contesting.com/_towertalk/1998-09/msg00477.html

Dow Corning High-Vacuum Silicone grease comes highly recommended by some 2-way radio pros.  I have my own tube of it that will probably last me a lifetime.  Here is an Amazon link to it:  http://amzn.to/2hZEHAw

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A question was asked about whether DStar is becoming more or less popular, especially when DMR seems to be coming on strong.

My take (my opinion only, of course) is that DStar is declining in popularity, but truly DMR is experiencing explosive growth right now.  Some comparisons:

Even though DStar and DMR use the same analog-to-digital codecs, DMR’s has FEC (forward error correction) built into it, and there is much less “R2-D2” voice garbling than DStar when signal strengths get low.  In fact, because of FEC, DMR seems to get about 10-15% better range than even analog FM can do.  The only downside is that you’ll have to get your ear used to hearing band-limited, digitized audio.  This is the case for either DMR or DStar, BTW.

DStar is supported by one ham manufacturer, Icom, and has never caught on with any others.

DMR is a world-wide standard driven by the need to serve the professional 2-way radio crowd, so even though it didn’t hit the market until 2007, all sorts of radios and infrastructure are available for it now, driving down costs to $100 or so for an entry-level radio.  With DStar, I’ve always been annoyed by the “DStar tax” I would have to pay if I bought an Icom radio.

The best part of DMR for me is the wonderful volunteers that have set up several world-wide networks and charged exactly zero for the rest of us to join in.  There are tons of hams to talk to at any hour of the day.

The only downside to both DStar and DMR is that they have a bit of a learning curve as a barrier to getting started.  You can’t just buy a radio and put it on the air 10 minutes later.  That’s where a knowledgeable ham friend who has been down that road already can be invaluable in getting you started.  Now, that said, let me offer some quick steps to help you at least get to the front door of the house:

  1.  Go to http://www.dmr-marc.net/ and click on “Register ID” in the upper right-hand corner.  You will be registering for a user ID, not a repeater.  On the bottom of the next page, click “User registration” and follow the prompts where they will validate you, making sure you have an active amateur radio call.  Within a day or two, you will get an email from them with your new 7-digit DMR ID number.  You will later program this into your DMR radio.  Note that you can also go back to this website later to see what you or your friends’ DMR ID’s are, or to find the name of the person whose only info that came up was his DMR ID. Here is a direct link to the database search page:  https://www.dmr-marc.net/cgi-bin/trbo-database/
  2. Buy a DMR radio.  Most of us locally have started with the TYT MD-380, and it’s just over $100.  If you have a TYT, you’re much more likely to find help with any questions you might have.  Most of us bought them on Amazon, such as this link:  http://amzn.to/2j199am
  3. Install the MD-380 programming software on your PC (available here as a download after you sign up for their very good newsletter).
  4. Get one of us to email you a codeplug that you can program into your radio, and then you’re good to go!  We can also explain what a codeplug is, and how you can change it to suit your own needs.

Baofeng Throws Down With the New UV-50X3

UV-50X3Baofeng announced the new UV-50X3 tri-band mobile this past week. It is a full duplex, dual receive radio, with 500 memories each side. It features 2 meter, .70 meter, and 1.25 meter operations. Full 50 watts on 2M and 440, with 5 watts on 220. Initial reports are positive. Right now, this seems like a legit contender for those looking for a replacement to the FT-8800 that Yaesu has failed to announce a replacement for since discontinuing the radio earlier this year. Another radio that looks interesting is the new Alinco DR-735T/E. Both of these radios fill a gap left by the departure of the FT-8800 and other dual receive mobiles that have been replaced by significantly more expensive counterparts with digital features and many other bells and whistles that many operators do not feel a need for. Initial testing of the UV-50X3 seem to be positive with good audio reports and clean signals after RF analysis. This is not a UV-5R stuffed into a mobile package like the UV-2501 appears to be. Could Baofeng finally be a contender? Waiting for more reviews to arrive to make the call. Stay tuned!

Update: Miklor has a pretty good review (Of course he does!), including RF data. Check it out here: http://www.miklor.com/BT50X3/50X3_SpecAnal.php

RigExpert – AA-54 vs. AA-600

We’ve discussed the features of the AA-600 as being great, but the over $600 price tag is a turn off.  As I mentioned, I was lucky at one point when HRO had them on sale long ago and I think it was about $550.

 

But, there are lower cost alternatives.  If you only want it for your HF antenna, there is the AA-54 for only $335 at HRO as of today.  Don (AA6W) brought either this or the AA-230 Zoom at our tech night last month and I found it quite similar and seemed to perform well.

 

Here is a review of it at eHam

AA54

AA-1000… I still love my AA-600 (this picture and link are of the AA-1000 which has a higher upper frequency and cost.

New (cheap) Microphone for Yaesu and TYT TH-9800 Radios

MH-48 clone microphoneI found this inexpensive Chinese copy of the venerable Yaesu MH-48 mike on Amazon for $14.99.  At that price, even if the mike doesn’t sound as good as the original, you could open it up and pull out whatever replacement parts you need on your original mike, and throw the rest away!  Turns out that it actually sounds pretty good.  I bought one to try out on my TYT TH-9800 because I’m not too keen on the mike that ships with it.  Oh, it’s not horrible, but if you’re going to make a clone of a Yaesu radio, why not clone the mike as well?

That’s basically what this mike it–a true Chinese knockoff, right down to the “Yaesu Musen” small type and logo!  It pretty much feels like the MH-48 on your FT-1900, FT-2900, FT-8800, FT-8900 and etc.  The only difference I’ve found so far is that the PTT switch doesn’t have the nice tactile feel that the original does.  This one’s kinda squishy, but not horrible.

Anyway…if you’re going to try this out on your TYT radio, you’ll be disappointed to find that the PTT button doesn’t work.  Yaesu mikes run on 8 volts, and the TYT runs on 5v.  So, you have to open up the mike and parallel a 100 ohm resistor across another, then it works fine.

Click on the mike’s picture to go to its Amazon page.  For those with TYT radios that might want to try a “real” Yaesu mike, I’ve uploaded a pdf file containing the instructions for adding the resistor:

Yaesu MH-48 microphone with the TYT TH-9800

Btech 2501 + 220

UV-2501+220 (2)The word of the day is BTech 2501+220. Okay, maybe that is 2 or more words. Several local hams purchased these from Amazon, on sale, for about $100. The results were a bit of a mixed bag. At the heart of it is essentially a UV-5R or UV-B5, with the added band of 220Mhz, in a mobile friendly package, with 25 watts. You can read some some great information at Miklor, so there is no reason to reinvent the wheel here. It is a dual watch radio, with the typical awkward menu system typical of these radios. But once you have programmed a memory location a few times, it goes fairly quickly. And as is also typical, it is easier if you use either software from the BTech web site, or Chirp.

The “mixed bag” experience primarily deals with the transmit audio being fairly muddy, muffled, and dull. One cure is:

Continue reading “Btech 2501 + 220”