I keep an electronics test bench and I love repairing old radios or building other electronic or amateur radio projects, usually late at night listening to shortwave or talking with other hams. My Amateur call sign is KM5Z.
This little old radio was given to me by a good ham radio friend of mine. It was excess to his needs and he called it a challenge: what can you do to improve this ugly old radio. And it was an Ugly Duckling, in very rough shape. As a portable, how many beaches had it visited? It was used so much the handle is gone! How many vacations or garages had it provided radio?
It’s a Reflex
Some research turns up that this is a nice example of a very simple Reflex radio. The first Tube, a 1A7G, tunes the signal. This is fed to the 1N5G which amplifies the IF signal. Note that the Volume Control wiper sends the incoming IF back to the input of the 1N5G.
Eventually a signal exits the 2nd IF Transformer to the Diode Plate of the 1N6G where the AM is Detected. The rest of the tube is an Amplifier for the Speaker. Each stage does double-duty!
Also, a simple AVC is provided via the Audio Transformer which, using the Screen Grid of the 1N6G, controls volume.
Together, with the three tubes (and the 1N6G is basically 1A5G with an added diode), the current draw is only 150 ma for filament and just under 7 ma at 90 volts plate.
This radio was marketed under Sentinel’s own brand, and also as an “Aria” branded radio, which was a department store brand. “Aria” was sold in Allied Stores of New York (ref: from ‘radioremembered.org’, “ALLIED STORES (private brand Aria), 1440 Broadway, New York, N. Y.”).
Completed So Far
Inspected and cleaned.
Some of the wicker-covering was peeling; some glue repaired this.
Cabinet blocking inside was loose – glued to reinforce.
Missing Handle – Replaced with a not-quite-Repro quality (but functional) leather strap.
Replaced resistors and capacitors as needed, testing for significant out-of-tolerance.
The S-120 resided in my office at work for almost a year until it developed an annoying 60-cycle hum that finally wouldn’t go away once it warmed up. Time to replace the electrolytics.
The Hallicrafters S-120 is essentially the same circuit as the S-38 series: an All-American 5 tube, minus the rectifier — replaced with a selenium rectifier. I bought this swell little radio from a fellow who thought it was dead, except for a few AM Broadcast stations. I brought it home and after a quick spray of Deoxid on the bandswitch and 3-in-1 oil on the tuning shafts (they were almost frozen) within 10-minutes it was working on all bands. Total cost: $10.
Antenna is a ferrite rod, built-in. The rear panel has clips to hold an extending rod antenna — mine is missing. Variations of this model include the SW-500 (same, but a sort-of slate-blue metal cabinet), and the WR-600 (same, but a wood cabinet). It’s a swell consumer-level general coverage receiver, and works great when provided a proper 75-foot long-wire plus a solid ground.
The knobs are plastic, the chassis is separated from the outer cabinet by p
lastic spacers and screw attachment points — this is a hot-chassis radio. The ‘ground’ in the schematic is actually B-; chassis is separated from B- by C29 and R18 (in parallel). Polarizing the power cord forces B- to always be the ‘neutral’.
C31 – A, B, C, and D – the 4-in-1 electrolytic capacitor sits above the chassis, the same side as the tubes. Unfortunately, there’s no good place to put a terminal strip; plus the leads to the 4-in-1 would have to be spliced to extend above the chassis. So, I relented and put the 4 individual caps near their + connection point; B- is available at several points, which makes this a convenient way to go. An alternative would be to measure this 4-in-1 electrolytic and contact Hayseed Hamfest for a modern replacement. At the time of this writing, they have an exact replacement for the ‘can’ in the S-120.
Updates as of 2008:
Replaced the 4 Electrolytics, leaving the old 4-in-1 in place, but not electrically connected.
Replaced all the tubulars, basically any by-pass capacitors.
Reception is extremely strong on all four bands. Didn’t do an alignment.
Polarized the power plug.
Added a safety cap from ‘after the power switch’ to B-
After rotating the radio home, and an extended stay playing there, the selenium rectifier gave up it’s ghost, with the accompanying stink. The selenium rectifier was replaced with a modern 1N4007 diode and a series 200 ohm, wire-wound resistor. The modern diode has quite a bit less voltage drop than the old selenium, and the resistor compensates to keep all the internal voltages ‘pretty close’ to what’s on the schematic.
Owners Guide, a great reference on setting up an antenna for Broadcast and Shortwave listening, as well as the radio’s basic controls.
If your’e going to own a Beofeng radio, you might as well have a cheap knockoff microphone to go with it. So, off to eBay we go.
And, surprisingly, for a Chinese purchase, it arrives in about 2 weeks.
Works perfectly. It’s light – there’s nothing to it but the essentials. I have no idea if the Beofeng logo is ‘official’ or pirate. Cost: $2.89, free shipping.
This is great. Now I’d like another one to hack up, for other little radios I’ve built. My second order was placed during Chinese New Year, and it takes an additional week to arrive.
This one doesn’t work – no audio. And it has a small rattle inside. Well, whaddaya expect for $2.89? Out with a T9 Torx screwdriver. Turns out the electret capsule is soldered, but… somehow there’s no connection. Fixed it by soldering from the electret capsule to another exposed point.
But look at the PCB: the solder-mask is bubbly. It’s just poor quality. Heck, I don’t know how they can provide the plastic shell, the wire in the cable, the dual plug, the electret capsule, a tiny right-angle tactile button, and the screws — for $2.89, shipped.
• 1 3 oz package of Orange Jello
• 1 cup boiling water
• 1 9-ounce can crushed pineapple with juice *
• 1 tsp lemon juice
• pinch of salt
• 1 cup grated carrots
Empty gelatin into a small mixing bowl. Stir in the cup of boiling water.
Stir thoroughly until the gelatin has dissolved.
Add the pineapple (including juice), lemon juice, salt, and carrots.
Chill ’til thickened.
This recipe seems to be a variation of a one found in a 1920s Jello Recipe booklet The Greater Jell-o Recipe Book, called “Golden Glow Salad”, page 18, but with the substitution of Orange Jello for Lemon, and lemon juice for vinegar.
* Nope, can’t substitute fresh pineapple – fresh pineapple has an enzyme that will prevent Jello from jelling.
• 1/2 cup butter, cubed
• 1/2 cup plus 2 tablespoons all-purpose flour
• 1 cups chopped celery
• 1 cup chopped green pepper
• 1 cup diced yellow onion
• 1/2 cup chopped green onions
• 1 can (14-1/2 ounces) chicken broth
• 1 cup water
• 1/4 cup minced fresh parsley
• 1 tablespoon tomato paste
• 1 bay leaf
• 1/2 teaspoon salt
• 1/4 teaspoon pepper
• 1/4 teaspoon cayenne pepper
• 2 pounds frozen cooked craw fish tail meat, thawed
In a large heavy skillet, melt butter; stir in flour. Cook and stir over low heat for about 20 minutes until mixture is a caramel-colored paste. Add the celery, pepper and onions; stir until coated. Add the broth, water, parsley, tomato paste, bay leaf, salt, pepper and cayenne pepper. Bring to a boil.
Reduce heat; cover and simmer for 45 minutes, stirring occasionally. Discard bay leaf. Add crawfish and heat through. Serve with rice.
Preheat oven to 425°.
Prepare pie crust and set aside.
In mixer bowl, cream butter with sugar. Add flour and combine thoroughly. Add eggs, one at a time, beating well after each egg.
[A note here: don’t beat the eggs mercilessly — just mix ’em.
If they’re beaten too much, the proteins will break down and the pie won’t be stiff.]
Combine vanilla and almond extract with buttermilk and stir.
Add to sugar / egg mixture. Mix well.
Pour into prepared pie shell and dust the top with a little nutmeg.
Bake: 10 minutes at 425°.
Then: reduce heat to 350° and cook 35—40 minutes, until custard sets. It should be firm.
Original Recipe: Ora Calloway, as published in: “The Only Texas Cookbook”, Linda West Eckhardt, Texas Monthly Press, 1981.
Mix cocoa, flour, sugar & salt. Beat the egg yolks, then add to the dry mix.
Then add milk gradually, while stirring in a pot over medium-high heat.
Cook until thick, beating it smooth. Stir (10-15 min). Once it’s thick, add vanilla after you take off the heat. Pour into a pre-baked pie shell. Put in the fridge to chill, add whipped cream, or use the left over egg whites for a meringue topping.