Gabil GRA-7350TC – WB3GCK QRP Amateur Radio

Round Two with the GRA-CFP2600

I made an early-morning run up to Evansburg State Park (US-1351, KFF-1351) for a quick activation. My plan for this activation was to try out my Gabil GRA-CFP2600 carbon fiber whip in the “Gabil-on-a-Table” configuration I have been using lately.

The weather forecast was showing a chance of late morning rain, so I headed out a little earlier than I normally do. On arrival, I grabbed my gear and headed for a picnic table in a wooded area that I’ve used many times over the years. It only took a few minutes to get the antenna set up with two 16.5-foot radials laid out on the ground. I easily found a good match on 40M and got started.

Operating at Evansburg State Park with the KH1 and Gabil antenna

My first 15 contacts came fairly easily, so I checked 30M and 20M. I picked up one contact on each of those bands. I could tell from the POTA spots that most of the activity was on 40M. That’s usually a good indicator of which bands are working. So, back to 40M I went. I picked up eight more contacts, bringing my total to 25. Subtracting out my time playing around with the antenna, I was on the air for about 40 minutes.

Gabil antenna, KH1, and CWMouse paddles. Once again, I neglected to take a picture of the carbon fiber whip in use.

One thing I noticed was that 20M was a little touchy to tune up. That’s something I’ve experienced a time or two in the past. This morning, the best I could do was an SWR of 2.0:1. The KH1’s ATU handled that easily. I’m sure I could have gotten the SWR lower by adding more radials—which I didn’t have with me. I’ll have to remember to pack a couple more radials next time.

In any event, it was a beautiful morning to be out in the park. Plus, I got home before the rain started. Timing is everything.

72, Craig WB3GCK

Whipping Up Some Contacts

In my last post, I mentioned how I damaged the telescopic whip, which is part of my Gabil GRA-7350TC antenna. The replacement telescopic whip has a long lead time, so I ordered a carbon fiber whip from Gabil in the meantime. Less than 24 hours after Amazon delivered it, I put the new whip to the test.

The new whip is the Gabil GRA-CFP2600 carbon fiber whip. Weighing in at just 78 grams (2.75 ounces), it’s a lightweight whip that breaks down into five separate sections. Fully assembled, it measures 248.4 cm (8 feet, 1.8 inches). That’s a tad longer than the stock whip. The sections are thin, but rigid. They slide together with a friction fit and make a distinctive “pop” when separated.

The five sections of the GRA-CFP2600 whip. The GRA-7350TC loading coil is on the left. Unfortunately, I neglected to take a picture of the antenna assembled for use.

To try it out, I headed over to Marsh Creek State Park (US-1380, KFF-1380) near one of the boat launches. Being a sunny and brisk October day, the parking lot was jam-packed with folks taking advantage of the weather. My original plan was to operate from a picnic table next to the lake. Since someone was already using the table, I operated from the truck.

To try out the new whip, I used a mag mount on the roof of the truck and ran the coax to my KH1 inside the truck. Using an antenna analyzer, I easily tuned up the antenna on 40M and got started. The band was as busy as the park. There were a couple of contests going on besides the large number of POTA stations I heard.

After finding an open frequency, I started calling CQ. The carbon fiber whip seemed to work well. I logged my first 10 contacts in just 10 minutes. After about 15 minutes, I was getting a headache from hearing stations on adjacent frequencies. I opted to seek refuge in the calmer waters of 30M. I picked up several more contacts before shutting down. After 40 minutes I had 22 contacts with four park-to-park contacts. I had P2P contacts on two bands from both WC1D and NI8W. Thanks, guys!

Before packing up the antenna, I did a quick check of the SWR on 20M and 17M. No issues tuning up on those bands. In my haste to pack up, however, I neglected to take a picture of the antenna installation. So, you’ll just have to use your imagination to picture a thin, black, eight-foot whip on a magnetic mount.

This carbon fiber whip has been on the market for a while, so I won’t bore you with a detailed review. YouTube has several reviews, and the Gabil website features two of them. However, there are a couple of pros and cons from my first outing with it.

Pros:

It’s super lightweight
Goes together quickly
Seems more rugged than the original telescopic whip
On the air, it seems to work as well as other short whips I have used. Certainly, as well as the original telescopic whip.

Cons:

Broken down, the pieces are significantly longer than the rest of the GRA-7350TC components. I have to pack them separately from the rest of the Gabil GRA-7350TC components.
Speaking of packing… Other than the cardboard tube it ships in, there is nothing provided to store the pieces in. I’m still thinking about how I will pack and transport this whip in the field. I’m thinking about buying a tent pole bag to carry it in. If any GRA-CFP2600 owners have suggestions, I’m all ears.

The GRA-CFP2600 whip is a novel design from the good folks at Gabil. It certainly has the high quality that is typical of their other products.

As always, this blog has no advertisers or sponsors. I bought the GRA-CFP2600 with my own funds.

72, Craig WB3GCK

Successful Activation with a Few Issues

I made a run up to French Creek State Park (US-1355, KFF-1355) for a quick, early-morning activation. While my activation was successful, it was not without a self-inflicted issue or two.

It was a beautiful, brisk fall morning here in southeastern Pennsylvania, so I set up at a picnic table. I used my Gabil GRA-7350TC antenna on top of the table, like I did a few weeks ago. As in the earlier activation, I used two 17-foot radials and no additional coax besides the Gabil RF choke. Using an antenna analyzer, I quickly found a good match on 40M.

I connected the KH1 and started calling CQ. When I picked up my phone to spot myself, I had no cell service. My cellphone carrier’s coverage is hit or miss in this park. The hotspot in my truck uses a different carrier, so I usually spot myself from the truck—something I neglected to do. Doh! Despite my oversight, I worked two stations that just happened to hear my CQs. After that…nothing. So, I headed back to the truck to post spots for POTA and WWFF.

Having overcome the spotting issue, things quickly picked up. I worked 16 stations before the activity on 40M slowed down. While tuning the antenna for 20M, I had some trouble getting a good match for some reason. Eventually, I got it down to about 2.3:1 and let the KH1’s ATU do its magic. I logged four more contacts on 20M before the QSOs dried up. I called it quits after an hour with 20 QSOs in my log.

The Hopewill Lake boat launch at French Creek State Park

But the fun didn’t end there. As I was taking the antenna down, I inadvertently manhandled the skinny top section of the Gabil whip and bent it over. Doh! I carefully straightened it out as best I could and managed to collapse it. At home, I checked it out, and the whip seems usable—albeit an inch or two shorter. I decided to order a Gabil GRA-CFP2600 carbon fiber whip and save the slightly damaged telescopic whip as a backup. Hopefully, that will be a bit more rugged.

While I was at it, I also ordered an exact replacement for the damaged telescopic whip. It wasn’t very expensive, and the smaller form factor when it’s collapsed is handy sometimes. I’ll just need to be more careful with it in the future.

72, Craig WB3GCK

Executing Plan B at US-1351

Sometimes things just don’t go according to plan. I have proven that many times over the years. My activation this morning was another example.

I drove up to Evansburg State Park (US-1351, KFF-1351) this morning for an early morning activation. My original plan was to operate from a picnic table in a wooded area, but heavily overcast skies prompted my decision to operate under a picnic pavilion.

My antenna of choice was going to be the “Gabil on a Table” configuration I used recently. I looked up at the ceiling of the pavilion and assumed there was enough headroom for the Gabil vertical on a table. Well, it did—until I slid the coil up to tune up on 40M. Doh! I probably could have used the vertical on 20M if I collapsed the radiator a little. Given the early hour, however, I really wanted to get on 40M. So, I took down the Gabil and packed it away.

Fortunately, with the KH1, there are always other options. I opted to operate the KH1 in tabletop mode with the whip, a right-angle adapter, and AXE extender coil. I had everything I needed in my KH1 box. No need to walk back to the truck to get stuff. Within minutes, I was up and running on 40M.

This configuration on 40M never ceases to amaze me. Within 10 minutes, I had my first 10 contacts. Not too shabby for a 45-inch whip and a huge loading coil. After making 20 contacts, the action slowed considerably. I logged a few more contacts on 40M before changing bands.

I could have moved up to 20M, but I didn’t feel like changing the antenna and counterpoise wire. Instead, I went to 30M. That band always works fine with the same configuration I use for 40M. Unfortunately, there wasn’t much activity on 30M (except for a station that started calling CQ on top of me). After spending some time fruitlessly calling CQ with no takers, I called it quits.

After about 45 minutes on the air, I had logged 25 contacts—all of them on 40M. I also picked up three park-to-park QSOs. My best “DX” this morning was out to Missouri.

The little KH1 came through for me once again.

72, Craig WB3GCK

Rainy Morning by the River

My (far) better half and I spent the weekend out in Central Pennsylvania to watch our grandson compete in a baseball tournament. With games scheduled for both Saturday and Sunday, I wasn’t expecting to get any radio time on this trip. I threw my radio backpack in the car anyway, and I’m glad I did.

My grandson’s team had back-to-back games on Saturday morning. It was cloudy and chilly, but it was worth it to watch them handily win both games. Towards the end of the second game, it started raining and continued on and off the rest of the weekend.

We got ‌word Saturday night that the rest of the tournament was being cancelled. The weather forecast indicated a 100% chance of rain on Sunday. While I felt bad that we wouldn’t get to see our grandson play in a championship game, there was a plus side: I could get out for an activation Sunday morning.

I left the house early Sunday morning and drove down to a park along the Susquehanna River. The Susquehanna is part of the Captain John Smith Historic Trail (US-4567), and I have operated from this park many times in recent years. In fact, I was just here a few weeks earlier.

The Susquehanna River on a rainy morning

We drove out in my (far) better half’s compact SUV, so I also brought my Gabil GRA-7350TC vertical and a mag mount. By the time I got to the park, the rain had slowed down a bit. I quickly slapped the antenna on the roof and tuned it for 40M. Because of the rain, I planned to limit my operation to one band. I didn’t relish the thought of going out there in the band to change bands. I set up my KH1 on the front console and got started.

After spotting myself, it took a minute or two for the hunters to show up. As usual, the Gabil and mag mount did a respectable job on 40M. My first contact was park-to-park with KG1A down in Florida. I also contacts with stations up and down the east coast and out to Missouri and Michigan.

It wasn’t always easy, though. There was a RTTY contest going on, so now and then a RTTY station would pop up on my frequency. The QRM was annoying, but somehow I worked through it. At one point, I had some audio QRM from a freight train passing by the park. Fortunately, that train wasn’t too long.

The mag mount has much more coax than I needed, so I coiled up the excess to create a choke. — The mag mount has much more coax than needed, so I coil up the excess to create a choke.

I got a text from my (far) better half letting me know they were going to be making breakfast soon. You don’t have to call me twice for breakfast. Besides, the coffee I brought along was almost gone. So, I packed up the KH1 and ventured out in the rain to take down the antenna. Fifteen minutes later, I was back at the house. I was only on the air for just 30 minutes, but I had logged 20 contacts, with one known park-to-park QSO.

The moral of the story: Always pack the radio gear, even if you don’t expect to use it. You just never know.

72, Craig WB3GCK

More Gabil on a Table

One of my favorite ways to use my Gabil GRA-7350TC antenna is on a picnic table within arm’s reach for easy adjustment. It’s a configuration I wrote about in a previous post. I wanted to try something similar using my Elecraft KH1, but with a minor twist.

What I had in mind was using the Gabil antenna on its tripod with most of the coax eliminated. To do this, I used a Gabil common-mode choke between the antenna and the KH1. Besides helping to keep RF off ‌the shield, it also provided a little extra coax length. This makes it a little easier to connect to the radio.

I had most of what I needed, except for an adapter to go from the choke to the radio’s antenna input. After scouring through my collection of connectors and adapters, I found what I needed: a PL-259 to BNC-M adapter. These aren’t very common, but I had acquired one somewhere along the way.

Now, I just needed a picnic table. For that, I headed to Evansburg State Park (US-1351, KFF-1351). I set up my Gabil antenna at a picnic table I’ve used several times before. I attached two 17-foot radials, which I laid on the ground. Using an SWR meter, I quickly tuned the antenna for an SWR of 1.3:1 on 40M. I swapped out the SWR meter for my KH1 and got on the air.

The Gabil vertical connected to the KH1 via a common-mode choke

After spotting myself, I logged my first 10 contacts in about nine minutes. Not bad for 3.5 watts to an eight-foot vertical. I hunted a couple of park-to-park contacts before moving up to 20M. I tuned around the band, and it seemed somewhat quiet. I called CQ a few times before getting a call from a very loud F4WBN. Right after that, I worked a station in Texas. Then the activity came to a screeching halt. My guess is that it was a little too early in the morning for 20M.

After spending more time on 20M than I should have, I went back down to 40M and picked up a couple more park-to-park contacts. I logged several more contacts after that before packing up. My one-hour effort netted 24 contacts, including five that were park-to-park.

My Gabil is an early version with scale markings applied with a sticker, rather than the engraved markings on the newer ones. I’ve already experienced a little peeling, so I wanted to add some band markings of my own. My plan was to use a Sharpie to mark the coil settings. I figured if I forgot to pack an SWR meter, I could at least get the antenna close enough for the KH1’s internal ATU to handle. It was a brilliant plan, except that I forgot to bring the pen. Doh! (Note to self: Add a Sharpie to the backpack.)

All-in-all, the Gabil proved its worth once again. It’s quick to setup, gets the job done, and it packs down small.

72, Craig WB3GCK

Using the Gabil Whip with the KH1

A while back, I came across a video by Aaron W4ARB in which he showed how to adapt the whip from a Gabil GRA-7350TC antenna for use with the Elecraft KH1. The Gabil whip is just over seven feet long, providing some height advantage over the KH1’s 45-inch whip. Since I had both the KH1 and a Gabil antenna, I gave it a try.

Aaron’s video gives you all the details you need, so be sure to go check it out. Since the Gabil and the KH1 whip use different thread sizes, Aaron found an inexpensive adapter to make it work. It reduces the M10 thread the Gabil whip requires to the M4 thread mount on the KH1. The longer whip weighs a bit more than the KH1’s whip, so Aaron used the KH1 on a picnic table with a Tufteln Right Angle Adapter. I just happened to have one of those in my KH1 kit.

To test this out, I drove out to French Creek State Park (US-1355, KFF-1355) and set up at a secluded picnic table. Using the adapter, the Gabil whip attached perfectly to the KH1 angle mount. I set up for 40M, using the Elecraft AXE1 coil and a 33-foot counterpoise wire. Aaron elevated his counterpoise wire for improved efficiency. Being lazy by nature, I just laid mine on the ground.

I set the KH1’s antenna switch to the 17M/15M position to use less loading inductance. In order for the KH1’s ATU to achieve a decent match, I needed to partially collapse the Gabil whip by two sections. In this configuration, the antenna is only slightly longer than the KH1’s whip, but it seemed to get out OK. I easily made the requisite 10 contacts, including a two-way QRP park-to-park contact with a station in Michigan.

Given that I had to partially collapse the Gabil whip on 40M, I’m not sure it provides a significant improvement over the KH1 whip. It certainly works, though. A smaller loading coil would be great.

The Gabil whip antenna mounted on the Elecraft AXE1 coil

At this point, I did a little antenna experimentation. Using the fully extended Gabil whip, a 13-ft counterpoise wire, no AXE1 extender, and the switch in the 17M/15M position, the KH1 easily found a match on 20M. I also got it to load on 30M, but I neglected to make a note of the exact configuration I used. I’ll have to try that again another time.

My setup. The Gabil whip is mounted directly on the right angle adapter for 20M

The longer whip really seemed to work well on 20M. In short order, I worked nine stations, including five in Florida. I packed up after an hour on the air, with 20 contacts in the log.

This was hardly a scientific evaluation, but the KH1 and Gabil whip is a combination I will definitely use again. Thanks to W4ARB for the idea and the great video.

72, Craig WB3GCK

Testing a New Mag Mount

On those occasions when I do an activation with my (far) better half’s car, I have been using my Gabil GRA-7350TC antenna on an old magnetic mount. Because of a recent issue with the mag mount I’ve had for 20+ years, I finally had to replace it. Today was the first opportunity I’ve had to use the new one.

While visiting my daughter and her family over the Christmas holiday, I headed out to activate the Captain John Smith Historic Trail (US-4567). Normally, when using the GRA-7350TC and mag mount on my (far) better half’s car, I can easily get the SWR down less than 1.5:1 on 40M. This time was different; the tuning seemed very finicky. I eventually got it close enough to use with the KH1 and completed my activation. As I was packing up, I noticed some damage to the coax where it enters the mount.

This old mag mount has seen many years of service with a VHF/UHF antenna on my truck before being pressed into service with the Gabil antenna. It’s amazing it lasted as long as it did. I decided that trying to disassemble and repair it was more trouble than it was worth.

I ended up buying a Tram magnetic mount on Amazon. This one is a real beast. It’s five inches in diameter and weighs a whopping 2.6 pounds. It’s probably overkill for my intended use, but I figured the larger diameter would provide better coupling to the vehicle. (Spoiler Alert: It does.)

My new five-inch magnetic mount — Tram magnetic mount

To try it out, I headed out to Marsh Creek State Park (US-1380, KFF-1380) and set it up on my truck. The attached coax is 17 feet long. That’s way more than I need, so after feeding it through the passenger-side window to my Penntek TR-35 (5 watts, CW), I coiled up the excess.

The Gabil GRA-7350TC antenna and magnetic mount on my truck

I started out on 40M and was surprised to see I could tune‌ the Gabil antenna down to 1.3:1 SWR. That’s better than I could ever get using the old mag mount on my truck. It was slow going on 40M this morning with a lot of fading. I could only manage about nine contacts before moving up to 30M.

Up on 30M, things picked up dramatically, but the most productive band was 20M. My contacts on 20M included Germany, France, and two from Finland. After logging 42 contacts, I pulled the plug and headed home for lunch.

So, the new mag mount should work great on my (far) better half’s car. Sadly, my old mount is now destined for the trash. I certainly got my money’s worth out of it, though.

72, Craig WB3GCK

Another Short but Successful POTA Activation

Lately, I’ve had to squeeze in my ham radio opportunities whenever I can. (That seems to be a common theme for this blog these days.) This past weekend was a perfect example. While spending the weekend with family in central Pennsylvania, I got in a very short activation and still made it back in time for breakfast with the family.

Always the early riser, I was up on Sunday morning before the rest of the family. After grabbing a quick cup of coffee, I threw my backpack in the car and headed out just after sunrise.

I activated the Captain John Smith Chesapeake National Historic Trail (US-4567) from a boat launch in Lancaster County. Equipment-wise, this activation was a carbon copy of my last visit—minus the paddle issues. I used my Elecraft KH1 in my (far) better half’s compact SUV. Once again, I used my Gabil GRA-7350TC vertical and magnetic mount on the roof of the car. The paddles I used this time out were the Ashi Paddle 45 from N6ARA Electronics. (More on those in a future post.)

After parking in my usual spot, I placed the antenna on the roof of the car and roughly adjusted the coil slider for 40M. I got out my antenna analyzer and conected the coax to fine-tune the antenna. However, when I turned on the antenna analyzer, it showed a 1.26:1 SWR—no adjustment needed! I couldn’t do that again if I tried.

After hunting for a few park-to-park contacts, I found a vacant frequency and started calling CQ. Like on my last visit, the 40M band was so productive I spent my whole activation there. I operated for about 30 minutes, logging 19 contacts—not too bad for about 4.5 watts into an eight-foot vertical on a mag mount, I guess. Once again, I connected with N4JAW (aka Ham on a Bike). Jim was out doing his usual bike-portable activation at US-7956 in Kentucky.

Some morning fog on the Susquehanna River

I packed up in a couple of minutes and was back at the house about 15 minutes later. My time on the air was a little shorter than I would have liked, but at least I had no paddle issues this time.

72, Craig WB3GCK

Paddle Problems & POTA

My (far) better half and I spent the past weekend with family out in central Pennsylvania. During the weekend, I squeezed in a quick, early morning POTA activation. The great band conditions made for a fun activation, but paddle problems made it challenging at one point.

On Saturday morning, I was up before everyone else. After downing a cup of coffee, I took a short drive to a boat launch on the Susquehanna River to activate the Captain John Smith Chesapeake National Historic Trail (US-4567).

We drove out in my (far) better half’s car, so I used a simple antenna setup that produced decent results in the past. I used my Gabil GRA-7350TC on a small magnetic mount. Like the last time I used it on my (far) better half’s car, I easily adjusted it for a 1.3:1 SWR on 40M. I fed the coax through the passenger side window.

Gabil GRA-7350TC antenna on a magnetic mount

Inside the car, I set my Elecraft KH1 on the center console. I used my cheap QU-21C paddles attached to a clipboard with a homebrew magnetic mount I made for them.

The 40M band was hot with no trace of the QRM I experienced the last time I was there. It only took 14 minutes to log my first 10 contacts, the contacts came in steadily for the next 45 minutes.

I was cruising right along for about 30 minutes until my cheap paddles decided to start dropping “dits” here and there. Based on my crazy sending, I’m sure some folks thought I was experiencing some sort of medical emergency.

I frantically searched for my N6ARA Tiny Paddle that I always carry as a backup. Of course, they were nowhere to be found. I ended up using the stock KH1 paddles attached to the radio, with the KH1 on the center armrest. This setup was an ergonomic nightmare, with my elbow in the backseat area. Despite the awkward position I was in, I was able to finish up my activation.

My setup after my paddle problems started. On hindsight, I could have arranged things better to make my operating position a little less awkward.

After an hour, I had 39 contacts in my log. I was so occupied on 40M, I never got around to trying the higher bands. My log included 7 park-to-park contacts. One of those was with N4JAW (aka Ham on a Bike). It’s always fun working Jim down in Kentucky.

I also heard from my friend, Greg WA3GM. It had been a while since our last QSO, so it was great to hear him again.

The Gabil antenna and mag mount setup once again proved to be a great antenna when using my (far) better half’s car. With about 4.5 watts out on 40M, I worked stations up and down eastern U.S. and Canada and out to several mid-west states.

The QU-21C paddles, however, are a different story. This is the second time I have had issues with them. A squirt or two of contact cleaner will usually fix the problem—for a while, anyway. As they say: You buy cheap, you get cheap.

And, of course, I found my N6ARA paddles as I was packing up. Doh!

72, Craig WB3GCK