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W2CO's Ham Shack - Thomas Walsh

Thomas Walsh
Extra Class
W2CO Ham Since 1969
United States

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Other Callsigns
WN2BXS 1969-71, WB2BXS 1971-85, N0DYR 1985-95, W2CO 1995-present, also GROL w/Ship Radar 1991

My Ham Radio Interests
Active in HF CW, HF Digital Modes, HF DXing, Satellite operations - VHF/UHF/MW now active on ISS APRS packet, Satellites worked in the past - AO-10 mode B, AO-13 mode B, AO-40 mode U/L/S.

Collins, Drake, Kenwood, Icom, Yaesu, Ten Tec, Hallicrafters, Alpha among others.

Other Interests
Classic Cars and Motorcycles, Original Music Composition

Check out our music page at

We're #2 for instrumental locally

Some of our music has cw and other ham radio sounds incorporated into the songs. See if you can copy them.


W2CO's Blog Post - 12/2/2019 8:25:34 AM

What's up with picture uploads?

I've tried various resolutions and sizes, no good. Are there no more pictures allowed..
Comment from WB4IUY 12/7/2019 7:16:24 PM
Hi, I sent the same message to support. They said the server was out of space for that. The income from advertisements has been so low that it's not supporting the system any longer, and the whole website may shut down forever as of this coming May when it's time for contract renewal. Sure hope it doesn't happen, but this stuff does cost $$ to operate.


Comment from W2CO 12/8/2019 8:21:15 AM
Thanks, I figured it was something with storage space, makes sense with around a million worldwide who join and upload stuff, but never contribute. Same old..Same old.

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W2CO's Blog Post - 12/1/2019 5:26:19 PM

Repairing Icom IC-751A

Upgraded rf amp to J310 jfets in RF board, PLL good except missing 2lo output, changing 2sc383's in 2lo output circuit.
Pics to follow..
Comment from WB4IUY 12/7/2019 7:18:03 PM
Great t hear the progress. What was the improvements with the J310's?


Comment from W2CO 12/8/2019 8:33:15 AM
The reasons for J310 is #1 the 2sk125's are no longer made and are practically unobtanium. I found a few but will not pay the 15-20$ a piece for them. #2 The J310 has a higher D-S max voltage, up to 60v vs. the 20v the 125's had. #3 the J310 have a bit more gain and better noise figure than the 125's. Don't forget the original parts are over 30 years old now, There was no warning.. Actually one of the 125's blew and took out one of the 8v regulators. That was the first problem. The symptom was the RX front end went completely dead! There are two amplifier sections, one for rx and the other for tx. The J310's require some pin swapping, ie; the gate is on the end, (not the middle pin) so one must swap the leads to match the circuit. I used thin heat shrink to avoid them from shorting out. If I remember correctly, the source and gate pins get swapped so the gate is middle, then align the backwards to silkscreen to get S G D .

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W2CO Updated Profile - 12/1/2019 5:19:32 PM

W2CO is Connected to the following - 12/30/2017 9:54:10 AM

W2CO Uploaded a Picture - 12/30/2017 9:54:10 AM

The blower is louder than our furnace blower
The blower is louder than our furnace blower

W2CO Uploaded a Picture - 12/30/2017 9:53:29 AM

Finally added step start to 3A CCA PS
Finally added step start to 3A CCA PS

W2CO Uploaded a Picture - 9/7/2016 12:18:47 PM

2m/70cm on az/el rotor = great satellite setup
2m/70cm on az/el rotor = great satellite setup

W2CO's Blog Post - 8/14/2016 8:54:14 AM

Broadband Fool's Gold

The 'Great broadband hope' it's not...

Broadband over power-lines (BPL) has been hailed as the "great broadband hope" by FCC commissioners past and present who believe it will usher in a new age of competition. Others lean on world-wide trial failures as evidence the technology is doomed-for-obsolescence; during its run bringing plenty of trouble (and interference) to areas contemplating the option.

BPL is a system that is being tested to provide broadband Internet service via powerlines to power outlets in homes and is a last mile technology. The system uses radio frequencies that will radiate into the air and cause interference to several licensed communications services including Amateur Radio. The frequencies BPL uses in general is 1 to 80 megahertz (MHz). Of particular interest is the band of frequencies known as HF, which is 1 to 30 MHz . This part of the radio spectrum has very special properties not found elsewhere. With this band, one can communicate around the world with very minute power levels. This is due to the fact that radio waves in this band can bounce off the ionosphere multiple times to get to a faraway destination. Other portions of the radio spectrum, like that used by 802.11 wireless LANs, are essentially line-of-sight. This means that the signals cannot bend or bounce off the ionosphere, but they can only propagate like light ? in a straight line and shorter distances.

The medium of BPL, the powerline cable, unlike other broadband mediums such as copper twisted pair, fiber, and coaxial cable, is inherently unsuited for carrying the frequencies BPL uses. Power lines, twisted pair, and coaxial cable all act like natural low pass filters, meaning higher frequencies are attenuated more than lower frequencies when attempting to transmit them through the medium. The exact slope of the graph of attenuation depends on the specific construction of the material, but in general, twisted pair is suitable up to 100 MHz and coaxial cable can go up to about 3 GHz. Power lines are suitable for up to perhaps 350 kHz or so. The exact figure will vary and is unimportant for this discussion, but note that this is kilohertz, not megahertz or gigahertz. The medium of BPL is simply not suited for broadband data.

The other property of the medium chosen for BPL is its radiating capability. Unlike all other broadband mediums, power lines are excellent radiators of the frequencies BPL uses. Copper twisted pair, coaxial cable, and fiber are all inherently non-radiating self-shielded mediums. Powerlines act like a natural antenna and ?lose? the BPL signal out into the air. The resulting interference can vary from a noticeable noise to a ?deafening roar? on radio equipment which drowns out all communications.

BPL has been tested and deployed on a limited basis in other countries and was rejected in some places due to interference issues. BPL vendors may claim ?new technology? and advances have now made it possible, but the fact is they can?t change the laws of physics. High speed data must occupy a certain amount of ?bandwidth? and power lines which were designed to operate at 60 hertz will radiate radio frequency energy that is applied to them. Only changing power line construction (i.e. coaxial cable) would eliminate this radiation. BPL proponents reject this as being too costly, but that would be the cost to make this a real viable technology.

Users of the affected radio spectrum cannot be relocated, or at least not economically or in a timely manner. All of the services that use HF bands require the characteristics that only HF spectrum exhibits. There would also be huge international treaty implications with any relocation. Relocating government and military services alone would take years as the FCC would have to structure a migration plan. Chances are it would be ten years before this could be completed and it?s likely that power companies will have run fiber to the home or DSL and cable will finally be ubiquitous. Perhaps the largest issue to tackle though is where to move these services in what is an already overcrowded spectrum.

If it was determined that relocation was the way to go, this would be very irresponsible as HF radio bands are a unique natural resource. No other radio spectrum can provide worldwide communications without any supporting infrastructure. The military (and Amateurs for that matter) have had satellites at their disposal for years, but HF is still in use as it provides unique capabilities that satellites just can't. Internet technologies such as email, streaming media, and instant messaging, or cell phones simply cannot take the place of the wireless infrastructure-free communications capabilities that HF provides.

Destroying a large portion of wireless spectrum is not justifiable because it benefits more people. There are many examples of this in society where reallocation of a resource would benefit more people, but it would be detrimental long term to the people and the resource itself. Right now, Amateur frequency allocations belong to the people internationally and can be enjoyed in nearly every country by simply passing a test and getting licensed. Once they are given to a business interest, they cease to be the public's and can only be used as a customer of that business. BPL impacts other groups including government, military, shortwave, aviation, maritime communications, and CBers, so this would have national security and international implications as well. BPL has been linked in some rhetoric with increasing ?homeland security?. BPL in fact takes spectrum away from government agencies directly tasked with protecting the country.

To deploy BPL an up front investment must be made in BPL headend / injection point equipment and repeaters -- it's not as simple as the FCC Commissioner makes it sound, as if all powerlines can immediately be easily lit up. There's going to be significant recurring costs in backhauling the IP traffic from the numerous BPL injection points serving an area. Neither DSL or Cable has this recurring cost or need for multiple network origination points. These costs unique to BPL make it even less attractive for deployment in rural areas that Cable or DSL as customer densities and revenue potential is lower.

The scalability of BPL is questionable. Chunks of HF spectrum must be reused between repeater/injection point segments. With customer bandwidth requirements going up, over subscription ratios going down, systems will need to be segmented in a cellular fashion. This exacerbates the interference issue as more frequency chunks are in use in a given area. More avoidance of frequencies will be needed, making less spectrum available for use by BPL. The frequency chunks in use will need to be smaller to enable tighter frequency reuse, and the available bandwidth per injection point will get to a point where it won't be sufficient.

BPL is also lacking on the regulatory front. It has no protection from interference from licensed wireless services. This means your BPL provider has no recourse if a licensed wireless station knocks out your BPL service regularly. If BPL interferes with a licensed wireless station, the BPL provider must cease to operate the system if the interference problem cannot be solved. While on the surface one would think that this would inherently protect wireless communications, it places a huge burden on such services to expend time and money identifying and seeking resolution to interference issues. With such a weak regulatory basis and a system that is immediately at odds with incumbent services, why would anyone want to depend on BPL to provide reliable broadband?

The FCC recently released Notice of Proposed Rulemaking (NPRM) 04-29 which attempts to both encourage BPL deployment and address interference concerns. The NPRM basically proposes a national database of BPL systems and some interference mitigation techniques. Neither solve the interference problem. The database hopefully will aid in identifying BPL systems operating in a given area so that interference complaints can be filed more quickly with BPL carriers. While in general this is a good idea, it does little for mobile operations as it's impractical for such operators to research ahead of time before travelling into an area to determine if interference-free operation is possible. The interference mitigation techniques the FCC is proposing comes down to moving interference around in the HF spectrum until no one complains. The problem with this is that it's very difficult to find ?open space? in this spectrum that won't affect anyone. The NTIA alone has over 18,000 frequencies in use. BPL carriers will receive an interference complaint, reconfigure their system to use other frequencies, only to interfere with another service. As BPL systems need more spectrum to feed a growing number of customers, more cells, and an increased demand for bandwidth, this interference avoidance juggling act will become impossible.

Radio Amateurs have been the most vocal in defending the radio spectrum, especially in Internet forums. Amateurs do not oppose broadband deployment, and in fact welcome it as most are born techies and use the Internet extensively. Some Amateur applications such as VHF repeater linking systems and position reporting systems actually use the Internet for connectivity and messaging. It is the ill effects of BPL on wireless spectrum which Amateurs vehemently oppose.

In summary, power companies should be building for broadband dominance in the coming decades with viable technology such as fiber, not for the next year or two with doomed-for-obsolescence technology. Wireless spectrum should be used for wireless applications, not to accommodate a wired network that pollutes the spectrum. The risk to critical licensed communications services is too great, the technological and regulatory foundation of BPL is too weak, and when compared head-to-head with other technologies, BPL loses on both the business model and technical capability sides. BPL appears all glittery, but in reality it's nothing more then Broadband Fool's Gold.
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W2CO's Blog Post - 8/13/2016 4:37:46 PM

YC-156 Input tuning

Input pi section working on 12m, input swr <1.3:1
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W2CO Uploaded a Picture - 7/17/2016 8:21:34 PM

Yet another early hybrid comes back to life! SBE-34 rf section needed tuning, working great now..
Yet another early hybrid comes back to life! SBE-34 rf section needed tuning, working great now..

W2CO Uploaded a Picture - 7/16/2016 6:40:21 PM

The K0RF team came in 1st place in the 2010 CQWW CW contest.
The K0RF team came in 1st place in the 2010 CQWW CW contest.

W2CO Uploaded a Picture - 7/16/2016 7:21:18 AM

The 4-1000 is also doing well, ran it last night on 20M CW, 599 in NZ! First call.
The 4-1000 is also doing well, ran it last night on 20M CW, 599 in NZ! First call.

W2CO Uploaded a Picture - 7/15/2016 7:02:10 AM

Just changed the hv caps in this TS-830S, the new caps are smaller then the originals, don't worry, they work just as well! Brought the plate voltage upto 920v now!
Just changed the hv caps in this TS-830S, the new caps are smaller then the originals, don't worry, they work just as well! Brought the plate voltage upto 920v now!

W2CO's Blog Post - 7/15/2016 6:50:59 AM

Hybrid transceivers

Don't forget the hybrid rigs from the 70's and 80's are going to need their hv caps changed soon! My trusty ts-830s just came up with half plate voltage and only 5watts in tune! Luckily in these hybrid rigs, if one of the two caps goes bad, the screen voltage also drops which saves the finals! So if you operate a hybrid rig from the 70's or 80's, and haven't changed the hv caps yet, watch the plate voltage and change the caps at the first sign of reduced values. My 830s normally has around 900v but it dropped to 820v last year but still operated ok. This year it went to maybe 350-400v and less then 100 when keyed! This indicates that one of the hv caps went bad! Change both when you do it because these caps have a definite lifetime from new of about twenty years. It doesn't matter if you run it once a day, once a week or once a year, in about twenty years they will go bad! This includes ts- 520, 530, 820, 830's , as well as yaesu Ft-101e, ex's etc., and many others from that era. "But I almost never look at plate voltage"...only plate current! Look at plate voltage everytime you operate the rig! It will save you time and money by catching it early.
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W2CO Uploaded a Picture - 7/14/2016 7:00:09 AM

A few more amps homebrewed by W2CO over the years. 4-1000 and a pair of 4-400's all in grounded grid.
A few more amps homebrewed by W2CO over the years. 4-1000 and a pair of 4-400's all in grounded grid.

W2CO's Blog Post - 7/14/2016 6:29:04 AM

Alpha 9500

BTW, the newest version of 9500 is even more reliable! It uses a hall effect sensor to replace the noisey pot for the bandswitch position sensor. This upgrade alone makes it way more reliable. That and we now install a fuse in series with the 40v (cathode) line to save the bias supply in the event a tube arc ever occurs!
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W2CO Uploaded a Picture - 7/14/2016 6:23:28 AM

A handy little cheat I use..
A handy little cheat I use..

W2CO Uploaded a Picture - 7/12/2016 1:46:20 PM

An Alpha 9500 pounding a dummy load on the bench.
An Alpha 9500 pounding a dummy load on the bench.

W2CO Uploaded a Picture - 7/12/2016 1:41:04 PM

YC-156 Input Tuning and Filament choke
YC-156 Input Tuning and Filament choke

W2CO's Blog Post - 7/12/2016 1:38:02 PM

YC-156 Amplifier

The YC-156 amp is coming along well. Now working on input tuning. The swr into the tube is too high on 12m at 2.5:1. A variable C, fixed L pi section is close to working. The YC-156 already has a high C so on these higher frequencies it's getting tough to tune the output as well, which of course also shows up on the input when keyed...More to come.
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W2CO is Connected to the following - 8/21/2009 8:29:00 AM

W2CO Uploaded a Picture - 8/21/2009 8:29:00 AM

U/L/S band dish
U/L/S band dish

W2CO Uploaded a Picture - 8/21/2009 8:24:59 AM

Mosley TA-53M-2
Mosley TA-53M-2

W2CO Uploaded a Picture - 8/21/2009 8:24:13 AM

Mosley TA-53M
Mosley TA-53M

W2CO Joined My Ham Shack - 8/21/2009 7:57:15 AM

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