Friday, June 29, 2018

The Nostalgic Hallicrafters S38-C Receiver

I have heard many QSO Today Podcast guest hams say that the S38, or similar, was their first receiver. I found a cheap Halicrafters S38-C Reciever on eBay. It was recapped by the seller. 





I am using the S38 up with a 10-foot indoor antenna. The 3:5 to 13 Megacycle band is stacked with shortwave stations. I hear English language broadcast from Holland and Beijing  It is nice to access so many stations without changing bands, I can tune them with a flick of my wrist. The sound is room filling. This radio does a good job at what it was designed to do. 



I can also hear 40 meters CW and SSB with the CW BFO turned on. Those signals may be too fleeting for serious ham radio. I have a hard time dialing in an exact frequency, but I hope to eventually hear Bob Heil's Ham Nation podcast and organ music broadcast on the WTWW shortwave station in Lebanon, Tennessee. 


Excerpt follows from http://www.stanwatkins.com/hals38.htm
The Hallicrafters S-38 was a basic, but very good communications receiver introduced in 1946.  The S-38 was Hallicrafter's entry-level communications receiver, priced at   $39.50   The radio was so popular, that it was produced in several variations and remained in production until 1961!  Famous industrial stylist Raymond Lowey designed the cabinet used in the S-38 through S-38C.  The S-38-D and S-38E were externally restyled and bore little resemblance to the earlier models.  The S-38 contained only six tubes, but included the following useful features:
  • Electrical bandspread with 0-100 scale
  • Automatic noise limiter
  • Four Bands covering .54 to 30 Mhz
  • Headphone terminals
  • Standby switch
  • Variable BFO for CW reception (later models omitted the variable BFO, reducing the tube count to five.)
To keep the receiver price low, all S-38s were transformerless designs.  This type of design works well, but presents dangerous shock hazards.  The safest way to operate an S-38 is to use an isolation transformer in the AC supply to the radio.   The set can be operated safely without an isolation transformer, but ONLY if the original back cover, bottom cover and rubber chassis isolators are in good condition. 





Greg N4KGL

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Monday, June 25, 2018

The N4Y 2018 ARRL Field Day Report from Kinsaul Park

Our callsign was N4Y. Field Day this year was a two operator, one transmitter operation on emergency power. Our exchange was "One Bravo Northern Florida." Dennis WA6QKN and Greg N4KGL were the operators. The venue was Kinsaul Park in Lynn Haven, Florida. It had plenty of space for antennas. We could not stay past the 10 pm park close. We resumed on Sunday morning until the end of Field Day. This was just as well as we were attacked by No-See-Ums after dark Saturday.

Dennis WA6QKN and Suzy
We started early Saturday morning. There was some drama as the medical alert service called and said they were dispatching EMS to my Mother's house in Dothan seventy miles away. It took about forty minutes to find out it was not a medical emergency. My Mother stepped out on the back porch and the door locked behind her. So Field Day was on after all.



Dennis and I, with help from Phil N4STC, erected a 272 foot 80 meter one wavelength square horizontal loop. It was fed in the center of the South wire. We tried a 4 to 1 and 2.5 to 1 balun. The 4 to 1 had the best SWR. It had a low of 1.9 on  80 meters and between 2 to 1 and 3 to 1 on the rest of the band. 40 meters and 20 meters were under 2 to 1 for the most part. The 2.5 to 1 balun had worse SWR than it previously had when feeding the loop at the corner.

The 80-meter one wavelength horizontal loop.
Our second antenna was the myantennas.com 80-10 1K Endfed which is 130 feet long. We oriented it on an East-West line at 20 feet up. The SWR was a little high on 80 meters but OK on the other bands. I was not disappointed with the loop, but the end-fed did the job as well, we think. On Sunday, we went with the end-fed alone on a North-South line. It served us well even on 15 and 10 meters which opened up Sunday morning.

Our solar assist.
The rig was the Icom 7300 powered by a 40 amp-hour Bioenno LiFePO4 battery. The battery was on a 50-watt solar panel and the Sun was out all day. It turns out the battery voltage was higher at the end of the day than the beginning. So the power we consumed was replenished by the solar panel. The Icom 7300 is a pleasure to use. I walked down the band making CW contacts with the spectrum scope. I used a 50 Hz filter to hear just one station at a time.

Continuing after dark
Dennis did a fine job on the phone mode. On Sunday, he worked a fifty station string on 15 meters. At the end, we tried our hand on PSK-31 on 10 meters. We got the hang of it and could do more next Field Day.  I attempted using the FM satellites with no success. I never got going with the linear sats. I did pull off five natural power contacts using a solar panel and a 58 Farad supercapacitor for 100 bonus points.

That is right!
We did have ham visitors and curious park-goers. One visitor was enthusiastic about getting his license. I used the rocket club trailer for hauling the gear. It had six water type fire extinguishers which puzzled the visitors. Suzy did her best job doing the meet and greet. No one went away disappointed.

Suzy
In the end, we made 180 contacts, 109 on phone, 57 on CW and 14 on digital. I believe we have some momentum going. We plan to have a big multi-operator, multi-transmitter Winter Field Day camp-out in Falling Waters State Park at the end of January. The enormity and enthusiasm for Field Day across the country, remind me that Ham Radio is doing well and has lots to offer on a social, technical, and service perspective.

Thursday, June 21, 2018

Change of Venue for the N4Y Field Day Operation

I decided to be closer to home for the June 23/24  Field Day. I moved the Falling Waters State Park reservation to a future date. The new venue is Kinsaul Park in Lynn Haven, Florida. The upside is the ample open space for antennas. The downside is that we will have to tear down by 10 PM Saturday Night and set up again on Sunday morning. Overnight is not allowed at the park.

Expected position of the 272-foot horizontal loop on the field.
Kinsaul Park happens to be where we previously tested the 272 ft horizontal loop. It nicely fits on the field. I am looking at configuring it as a square and feeding the antenna in the center of the South wire. This means the max gain of 40 meters will be North and on 20 meters the max gain will be Northeast and Northwest. Being in Northwest Florida, this orientation favors the rest of the USA to our North. We expect 40 and 20 meters to be the most active, The loop is an excellent 80-meter NVIS antenna. We will be checking 80, 15 and 10 for contacts. There usually is a brief high band opening during Field Day.
Using the Icom 7300 at Kinsaul Park
Our category will be B2,  2-person club/non-club portable using emergency power. The operators will be Dennis WA6QKN and me, Greg N4KGL. Our primary rig will be the Icom IC-7300 with power up to 100 watts. Our source of DC power will be Bioenno LiFePO4 batteries replenished by a 50-watt solar panel. The callsign is N4Y, and the exchange will be 1B Northern Florida.

The 50-watt solar panel.
I am planning to try for the 100 point satellite bonus. I have gear for both FM and linear satellites. I hear that the linear Sats are the better bet for Field Day due to the congestion on the FM sats. Only one satellite contact will count for ARRL Field Day

The Icom 910h for linear satellites

The Arrow satellite antenna
Another attractive bonus is Alternate Power. I will charge a supercapacitor bank either from solar or pedal generator, I will try for the five QSOs using the Elecraft KX2.  Each QSO is 20 bonus points.

The supercapacitor bank for the alternate energy bonus
Dennis WA6QKN will be a full-time participant this year.  We will trade-off operating and logging duty. We have been doing portable ops together for a while. He is the ideal Field Day partner.

The weather will be hot, but rain should not be a factor.
  • Saturday
    • Mostly sunny, with a high near 88. West southwest wind around 10 mph.
  • Saturday Night
    • Partly cloudy, with a low around 78.
  • Sunday
    • Mostly sunny, with a high near 89.
We welcome the local hams and the general public to come by for a visit. We are at the West end of 5th street in Lynn Haven. Our setup will begin around 7 am on Saturday. Field Day starts at 1 pm. We will have to tear down at 9 PM on Saturday Night. Sunday looks like a start-up at 7 or 8 and a 1 pm tear-down.  Of course, these times are approximate and may be modified.

Good luck everyone on ARRL Field Day!

Saturday, June 9, 2018

Field Day Antenna Testing for the AG6IF Loop and the MyAntennas 80-10 End Fed UPDATED

Phil N4STC, Dennis WA6QKN and I met Saturday morning at Kinsaul Park in Lynn Haven, Florida to do some antenna tests for Field Day. I had been interested in a one-wavelength 80-meter horizontal loop. I did some modeling with EZNEC. The loop looks like a good prospect for Field Day with 80-meter being NVIS, 40 meters is omnidirectional at 60 degrees elevation and 20 meters has four 30 degree lobes with gain. I obtained an AG6IF 2.5 to 1 balun sold on eBay with the 260 feet of wire required.


A panoramic view of the loop antenna setup
We set up the one wavelength AG6IF 80 meter Loop with a camo pole tripod at the corner feed point and seven 31 foot Jackite fiberglass poles to complete a square with 65 feet on a side. It resonated on 80, 40 and 20 meters. Initially, it dipped above the 40 and 20 meters band and we added twelve feet to the 260 ft supplied wire. That gave us an excellent SWR on the low end of 80 and across 40 and 20 meters. The load on the upper end of 80 meters is more than the Icom 7300 internal tuner can handle. That is no biggie. The loop was very quiet regarding background noise. We made a 20-meter contact with W0LAV in Missouri with an excellent report.

UPDATE: Myron WV0H had modeled this loop and had predicted in an email to me the need to add 13 feet of length. This was spot on. He also says the SWR would be better with a 4 to 1 balun. I will give that a try. Thanks, Myron!




Before I had settled on the loop, I ordered a MyAntennas 80-10 meter Endfed. The antenna is advertised as a no tuner antenna for 80 through 10 including the WARC bands. At the end of the session, we put up the 130 feet long end fed antenna flat and straight at 20 feet. Indeed, it has reasonable SWR on all the bands. I would use a tuner at some spots. There is no significant mismatch on the coax. We checked into the SouthCARs net using the EndFed.


Phil N4STC wiring up the balun.
Dennis and I will be camping at Falling Waters State Park, Friday and Saturday night for the June 23/24 Field Day. We might go with both antennas. We are on track to use the Icom 7300 as the rig. Thanks to Phil and Dennis for their help today. We are looking forward to the big event.


Checkin SWR with the Rig Expert-AA-54

Checking out the antennas on air with the Icom 7300.

Suzy getting some attention.

Sunday, June 3, 2018

N4Y Field Day Site Survey for a Horizontal Loop Antenna

Dennis, Suzy and I went up to Falling Waters State Park Saturday to survey our campsite and the adjacent open field. First, our campsite will be #5. It is a pull through type for an RV and therefore is wide. Fortunately, it is also deep. I believe it is the best campsite in the park, We will pitch an 8-man tent there. Our Field Day category will be B, two operators, and one transmitter. The callsign will be N4Y. We will camp Friday and Saturday night. Our Field Day operations start at 1800 UTC Saturday and last for 24 hours.

The open field behind the campsite
The back of the site borders an open field. We have permission to use it. However, we can't interfere with the volleyball court. We found looking out of the back of the campsite that the volleyball court is to the right, They have that area planted in grass. So to avoid that area there is an ample unplanted area to the left.

The campsite from the rear
We are seriously considering a 260-foot loop that is one wavelength at 80 meters. It can be a square or triangle. Let's assume it is a square with 65 feet on each side. We can align it with the compass points. I believe feeding the loop in the Southeast corner is the practical choice to minimize feedline length to the campsite. I am hoping the feedline length will be no more than 100 feet. We will need to elevate it over a trail that runs along the back of the campsites.

3-D radiation pattern for 260-foot horizontal loop on 80 meters
Modeling this loop with EZNEC I find that on 80 meters has maximum gain straight up ala NVIS. On 40 meters, it is omnidirectional but has the max gain at 60 degrees elevation. On 20-meters it has four lobes with a max gain of 10 dbi at 35 degrees elevation toward the Northwest. Unfortunately, there are nulls at the four compass points. You have to give up something to get gain. We might need a second antenna like a 20 meter vertical to fill in the gaps.

3-D radiation pattern for 260-foot horizontal loop on 40 meters


The antenna supports could be four camo pole tripods 20 feet high on the corners with four 30-foot Jackite poles in between. I will need to round up a few more camo poles. I have a 2.5 to 1 balun that could be used at the feed point. An alternate feed would be 300-ohm balanced line to an Icom AH-4 tuner. The determination of the matching system will need to be a field test here in Panama City. We can see if this antenna acts as advertised.

3-D radiation pattern for 260-foot horizontal loop on 20 meters
After the site survey, we set up the Icom 7300 at a pavilion. We played around with PSK-31 which is new to Dennis. We did not have it quite setup right on transmit, but we can work that out later. A heavy afternoon shower encouraged us to call it a day.


Dennis took more photos. See them at this link