Category Archives: Articles

Guest Post: Communications Service Monitors – A Radio Hobbyist’s Perspective


Many thanks to SWLing Post contributor, Mario Filippi (N2HUN) for the following guest post:

Communications Service Monitors – A Radio Hobbyist’s Perspective

Mario Filippi, N2HUN

(All photos courtesy of author)

Over the past few decades I lusted after a communications service monitor for my radio hobby but prices were always prohibitive; several thousands of dollars for a new model and tens of thousands for high-end ones. Not being a working professional in the communications field made it difficult to justify purchasing a piece of equipment whose price tag rivaled a down payment on a house. So, fast forward a few decades later and now life and times have fortunately changed for the better; the house is paid for, the job is secure, the income is finally steady, life is good financially, and to boot many of these older service monitors manufactured by Ramsey, Motorola, Wavetek, IFR/Aerotek, Cushman etc., are currently being sold on the pre-owned market at a fraction of their original decades-ago hefty prices. These service monitors are finally in financial reach of electronics hobbyists who will find many uses for these former electronic workhorses that toiled many years in the industry and now, in their golden years are being retired and becoming available for a second life via reuse/reincarnation/repurposing/reinvention.

Work of Art: Author’s Ramsey COM3 Service Monitor

Work of Art: Author’s Ramsey COM3 Service Monitor

So what exactly is a communications service monitor, or “service monitor” as the folks in the trade refer to? Well it is an instrument for servicing AM and FM radio equipment, although some units also have the ability to service SSB equipment. The service monitor is basically a highly accurate and precise receiver and low-power signal generator all in one allowing a technician (or electronics hobbyist) to perform service, repair, or alignment of radio equipment. Most of us have had the experience of owning a malfunctioning radio whether it is an AM or FM broadcast radio, two-way radio such as a CB (Citizen’s Band) radio, pager, or a ham radio transceiver, and that is where a service monitor proves its value and utility because now you, the hobbyist, can perform the work yourself.

My Friend’s Ramsey COM3010 Service Monitor, Big Brother of the COM3

My Friend’s Ramsey COM3010 Service Monitor, Big Brother of the COM3

As a radio enthusiast (shortwave, ham radio, satellite communications) for over half a century, I’ve definitely owned more radios than shoes; everything from AM, FM, shortwave receivers to CB radios to ham transceivers, all in different stages of health and vintage. For years I relied on standalone RF signal generators, audio generators, frequency counters, and CTCSS decoders to aid in rehabbing, troubleshooting, and aligning each of the many units that paraded past my radio shack. Then one day a friend showed me his service monitor, the Ramsey COM3010, another venerable workhorse still in production, and it was a defining moment; the time had come to invest in one.

Aligning a Uniden President Washington CB Radio Prior to Owning a Service Monitor

Aligning a Uniden President Washington CB Radio Prior to Owning a Service Monitor

My Ramsey COM3, purchased second-hand from an Internet auction site for $400.00 is a no frills, basic unit without the features found in more sophisticated service monitors having built-in oscilloscopes, spectrum analyzers, frequency sweeping ability, and frequency scanning ability. The COM3 was in production from the late 1980’s to around 2003 at a price of around $2500 (ca. 1989) and was considered a workhorse in its time, weighed 13 pounds with the internal battery, and was easily luggable from site to site. It covers from 100 KHz to 999.999 MHz and has become an invaluable tool in my radio shack for measuring a transmitter’s operating frequency and deviation, measuring receiver sensitivity, S meter calibration, and checking CTCSS tones on my two way VHF/UHF radios. My unit evidently had an easy former life as the only needs were to replace the internal battery, perform an external cleaning, check transmitter and receiver accuracy and check accuracy of the internal audio generator. Interestingly, Ramsey Electronics ( still services and calibrates COM3s.

Vintage Tempo One Transceiver Restoration Was Made Easier with the COM3 on the Bench

Vintage Tempo One Transceiver Restoration Was Made Easier with the COM3 on the Bench

So, if you’ve been dreaming of owning your own communications service monitor either as a hobbyist or small repair radio shop proprietor then start looking as there are plenty of used units out there; you’ll pay top dollar when buying from a commercial vendor but at least you’ll get some form of warranty. If instead you travel the same road I did, via an Internet auction site, there’s lots more risk involved, but the plus is you’ll save big if you do your homework by checking past auctions, seller feedback scores, and determining what price the market is bearing by looking at the winning bids. In closing, the COM3 owner’s manual is available on line by doing a simple search, and a review of the Ramsey COM3 by Larry Antonuk which appeared in the August 1989 issue of 73 Amateur Radio Magazine is also available as a free download.

Mario, thank you for another brilliant guest post! I always learn something new from your articles. By the way: I have that same Nye Viking straight key–it obviously pairs beautifully with the Tempo One!

One week of Hamvention, Air Force Museum, Wright Brothers and National Parks On The Air

DSC_4449I returned home last night from my week-log Dayton Hamvention trip around 8:30 PM.

The Hamvention actually ended at 1:00 PM on Sunday, May 22, but my buddy Eric McFadden (WD8RIF), his son Miles (KD8KNC) and I stayed Sunday night in Dayton, and Monday night at Eric’s home in Athens, Ohio.

After packing up our Hamvention booth (for Ears To Our World) on Sunday, we made our way to the nearby National Museum of the USAF–the largest aviation museum in the world. We visit the museum every year–and every year I discover something new.


This BC-348 can be found in one of the museum’s B-29 displays.

DSC_4443 DSC_4455

In June, the Air Force museum is actually opening a fourth building which will house an additional 70 aircraft in four new galleries.

If you’re an aviation buff–trust me–the  National Museum of the USAF is worth a pilgrimage to Dayton, Ohio.

NPOTA activations

Monday morning, Eric, Miles and I packed up, ran a few errands on Wright Patterson Air Force Base, then made our way to our first National Parks On The Air activation: the Dayton Aviation Heritage National Historical Park (HP11) and North Country National Scenic Trail (TR04) “two-fer” at Huffman Prairie Flying Field Interpretive Center in Dayton, Ohio.

Eric worked CW on 20 meters and I worked SSB on 40 meters using the LNR Precision LD-11 transceiver (which I’m currently reviewing) and my recently-purchased Hardened Power Systems QRP Ranger.

For all of my Monday NPOTA activations, I used the EFT Trail Friendly antenna I purchased at the Hamvention:


The EFT Trail Friendly Antenna made set-up a breeze: simply throw a line into a tree, hang the end of the antenna, then hook up the other end to the feedline/transceiver. No antenna tuner is needed for 40, 20 or 10 meters once the antenna is tuned for resonance. It packs up into a small bundle that easily fits in my radio go-kit (see photo above).

The LD-11/QRP Ranger/EFT antenna combo worked amazingly well and made for very quick deployment.

LNR-LD-11 and QRP Ranger NPOTA

I can easily fit the LD-11 transceiver and QRP Ranger on a foldable metal chair (my make-shift field table!).

My buddy Eric, I should mention, is typically on the leaderboard for NPOTA as he’s an avid QRP field operator.


Eric (WD8RIF) operating NPOTA with his field-portable vertical HF antenna.

You can follow Eric’s activations on or his website.

Eric's field-portable HF vertical packs up into this small canvas bag.

Eric’s field-portable HF vertical packs up into this small canvas bag.

We had a tight NPOTA activation schedule to meet Monday, but after packing up from our first sites, we took 30 minutes to stop by the Wright-Dunbar Interpretive Center and The Wright Cycle Co. museum in downtown Dayton.


Well worth the short visit! Next year, I’ll plan to revisit both museums when I have more time.

Next, we made our way to the second scheduled NPOTA activation site: the Charles Young Buffalo Soldiers National Monument (MN18).


Despite not having my antenna very far off the ground (my antenna line fell down one branch in the process of hanging) I still managed to work a pile-up of stations from Georgia, North Carolina, Ohio, Illinois, Connecticut, Michigan and Indiana. After Eric and I racked up a number of QSOs, we packed up our site in haste and made our way to the final activation of the day: the Hopewell Culture National Historical Park (HP15). We arrived as the Park Ranger was getting in his car to leave for the day!

At Hopewell, I managed to deploy the EFT antenna much higher off the ground. I worked a small pile up of stations from all over the region which, to my surprise, included two radio friends (Ed and Eileen) in Franklin, NC. Eric also worked blogging buddy John Harper, AE5X on 20 meters CW (got your message, John!).


All in all, it was a fantastic day to be outdoors and on the air.

Of course, a side benefit of doing National Parks On The Air activations is that you get to check out all of these amazing park sites.

Without a doubt, this was one fun-filled and radio-centric Hamvention week! It couldn’t have been better.


Part of my log sheet for NPOTA HP11 and TRO4 “Two-Fer” activations. Not bad for such a tight schedule!

Thank you

Many thanks to my friends Eric (WD8RIF), Miles (KD8KNC), Mike (K8RAT) and Christine (KM4PDS) for volunteering to manage our Hamvention booth for Ears To Our World. It was a record year for collecting donations. Many thanks to all of you for the support!

I’d also like to thank the SWLing Post readers who stopped by to visit our new location in the Silver Arena–it was great seeing everyone!

Now that I’m back home, I essentially have one week of emails and comments in my backlog to sort before hitting the road again rather soon. I appreciate your patience as I catch up. If you don’t hear back from me soon, it’s okay to give me a nudge! 🙂

Remembering the 5th anniversary of Radio Havana Cuba


Many thanks to SWLing Post reader, Jake, who writes:

Just passing along this scan of an Associated Press story about the 5th anniversary of Radio Havana Cuba. It ran in The Virginian-Pilot on May 8, 1966.

Fun read considering so many of us have listened to the station over the years.

Keep up your good work!

RHC Virginian-Pilot 5_8_1966

Wow–as of May 2016, RHC has been on the air for 55 years. Thanks, Jake, for sharing this bit of radio history!

Have you ever installed a covert shortwave radio antenna?

The Hammarlund RBG CHC-46140 (Photo by Rich Post, KB8TAD)

The Hammarlund RBG CHC-46140 (Photo by Rich Post, KB8TAD)

Yesterday, in a comment thread, SWLing Post reader Dan described a covert antenna he once installed in a student apartment:

I’m waxing nostalgic now, but I had a great set-up for a couple of years back in the ’70s. The receiver was a black WW2 Navy surplus Hammarlund RBG CHC-46140. (I still have it).

I was a student living in an apartment on top of a two story, wood-framed apartment building. The attic access for that building was from the ceiling of the wardrobe closet.

During a Christmas break I was probably the only occupant of the building. I snuck into the attic and installed a set of five switchable dipoles. I had a good 60′ of space to work with and the antennas were broadside to the southwest. This was quite a memorable listening post.

When I moved out, I cut the coax to the dipoles and used toothpaste and borrowed pieces of “cottage cheese” to fill the five holes in the ceiling. Those antennas are probably still there.

Indeed, I bet they are still there, Dan!

In reply to Dan’s comment, Walt Salmaniw, noted:

Dan, reminds me when I was stationed in Germany in the early 80’s.

We lived in old French officer’s quarters. Basically, 4 story buildings with the upper floor/attic uninhabited.

The Kenwood R-2000 (Photo: Universal Radio)

The Kenwood R-2000 (Photo: Universal Radio)

I put up some nice 60 m dipoles in that space, with a goal of hearing a lot of tropical band DX, which I did using my Kenwood R2000 receiver.

Those were the glory days of dxing!

Thanks, Dan and Walter, for sharing those stories. The thread reminds me of a post we published sometime back where one young listener installed a wire antenna in his home while his parents were away. (I can’t seem to locate that post at the moment for a link!).

Though not nearly as elaborate as Dan and Walter’s antennas, I did install a small covert antenna once myself.

In the early 90s, I lived in Grenoble, France, in a four bedroom house in which three bedrooms were occupied by university students. The landlord was a rather fussy elderly woman who lived on the ground floor. I never dared ask her if I could string a random wire outside my top floor bedroom window. Though she was mostly fair and even sweet at times, I knew what the response would be if I asked for permission: a firm “Non.”

One night, I opened the bedroom window and carefully connected a short wire antenna to a nail on the side of the house, above and slightly to the side of the window. I had to stand on the window and hang out of the house to do it.

The Realistic DX-440

The Realistic DX-440

The antenna dangled there the whole year I lived in that room and served me quite well. I’d simply open the window and clip it to my Realistic DX-440. I did remove the antenna before before I moved back to the States, but it was virtually undetectable against the  exterior wall of the house.

Other covert antenna installations?

Please comment if you’ve ever installed a hidden antenna as well. (I love this stuff!) Besides…who knows…your antenna might benefit someone in need of a hidden antenna today!

World’s first pirate broadcast on Easter 1916 to be celebrated

Antique-Radio-Audion(Source: Silicon Republic via Andrea Borgnino)

At an event in Trinity College Dublin (TCD) tonight (25 April), the centenary of the broadcasting of the Proclamation of an Irish Republic via shortwave radio in 1916 – considered by many to be the first pirate radio broadcast – will be marked.

While the men and women who took part in Easter 1916 were camped out in the GPO and other locations around Dublin, one group involved with the rebellion, led by Joseph Mary Plunkett, wanted to use the latest technology to spread the message of Irish revolt.

Having commandeered the Irish School of Wireless Telegraphy at the corner of O’Connell Street and Abbey Street – where the Grand Central Bar now sits – the group set up a ship’s wireless systems to broadcast a shortwave radio transmission, with the hope that a passing ship near the country would pick it up and report back to the US.

With Plunkett at the controls, the radio enthusiast issued a burst of Morse code that read: “Irish Republic declared in Dublin today. Irish troops have captured city and are in full possession. Enemy cannot move in city. The whole country rising.”

With some reports suggesting the broadcast was picked up as far away as Germany and Bulgaria, it is widely considered one of the first pirate radio broadcasts as, until then, point-to-point transmissions was the most common form of sending messages wirelessly.[…]

Continue reading the full article at Silicon Republic online…