Posts Tagged ‘Vintage Shortwave Receiver’

Posted on February 22, 2012 - by DLandon

Heathkit LG-1 Laboratory Type Signal Generator for Sale – SOLD

This is a very nice Heathkit RF Signal Generator that has been completely restored and calibrated. Included is the original manual (not a copy) in excellent condition. Original cable is included. I will only ship this unit to the lower 48 states because of the weight. Contact me by email at dlandon@vintagetubeelectronics.com if you are interested.

Posted on April 15, 2010 - by Vintage Tube Admin

Hallicrafters S-214 Receiver

The Hallicrafters S-214 was manufactured from 1967-1971.  This receiver is in excellent condition and has been restored to excellent working condition.  When I got the receiver it barely worked. The switches and controls were dirty, and it needed an alignment.  The case was extremely dirty and once it was cleaned up it looks really nice.  The power cord was replaced with a new one.  I also had to replace the dial lights.  The telescoping antenna is original.  I just replaced the button on the top of the antenna.

This receiver covers the AM broadcast band, FM broadcast band, and shortwave from 5.9kHz to 15.55kHz in four bands.  Fred Osterman in “Shortwave Receivers Past & Present” says this is a very scarce receiver.

Posted on April 15, 2010 - by Vintage Tube Admin

Hallicrafters SX-100 Communications Receiver

The Hallicrafters SX-100 is a 14 tube Double Conversion receiver that was made from 1955-1962.  This receiver is a Mark 1B.  I don’t know what year this one was manufactured.

This receiver is in excellent condition.  The front panel and paint are in excellent original condition.  The Bandspread knob has a small chip.  The line on the Bandspread glass is wavy.  I suspect that someone over the years tried to clean the glass and got the paint too wet and it slid on the glass.  I have had the glass silk screened back into original condition.

The receiver worked when I got it, but not very well.  I replaced all the paper capacitors.  All electrolytic capacitors were also replaced.  I do not trust any of the old capacitors to last, even if the radio works well.  Electrolytics are known to fail catastrophically.  There were some out of spec resistors, but nothing out of the ordinary for a receiver of this vintage.  Generally resistors in the audio section and the B+ circuitry are out of spec.

The second IF section is a sub-chassis mounted on the main chassis.  There aren’t any paper capacitors in this sub-chassis so there is no reason to remove that chassis.  The capacitors are mica and ceramic which are very reliable and not prone to failure like paper capacitors.

The 6C4 in the notch filter circuit, the 6C4 first converter oscillator, the 12AT7 in the second IF, and the 6SC7 audio amp and BFO were all bad and replaced.  The other tubes with the exception of the 6K6 audio output are original Hallicrafters tubes.  It’s common for the audio output tubes to go bad before any others.

I replaced the power cord, installed an inline fuse, and an inrush current limiter.  The inrush current limiter will help extend the life of the vacuum tubes by powering them up slowly.  The white tube in the rectifier socket is a 5Y3 solid state replacement.  This helps provide stable DC power and cuts down on the load on the transformer.  The 5 volt filament current is eliminated by the SSR replacement.

Alignment of the SX-100 was not particularly difficult.  Both IF stages were out of alignment.  The RF section just needed some minor adjustments.  I used a Heathkit audio frequency generator that produces 50 kHz output for aligning the 50.5 kHz IF stage.  I used an EICO AM modulated RF generator for the 1650 kHz IF stage.

Once I aligned this radio, it turned out to be extremely sensitive.  There is so much gain in the RF section, that I can only turn the volume up to 1 or 1.5 before it becomes too loud.  This is a really hot receiver!

I’m impressed with how well the notch filter works in a receiver of this age.

The Main and Bandspread tuning are gear driven with flywheels.  The tuning is very precise and incredibly smooth.  The only dial cord in the receiver is for the bandspread ganged capacitor and is a metal cable.  I don’t ever expect to have to replace this dial cord.

The SX-100 has SSB capability and seems to work quite well.  I am still learning about the SSB capability on this SX-100.  You can receive standard AM broadcasts on either Upper or Lower side band, which can eliminate interference that affects one of the sidebands but not the other.

There is a built in 100 kHz crystal marker to calibrate the main tuning.

The audio output is single ended (6K6) so it is not hi-fidelity, but sounds quite good.

This is an extremely nice receiver and is definitely a keeper.

Posted on April 15, 2010 - by Vintage Tube Admin

Hallicrafters S-76 Communications Receiver

This S-76 was manufactured in 1952.  The S-76 is a double conversion superheterodyne receiver with 10 tubes.  It has an extremely large S-meter.  For those of us that are a little older and our eyesight not what it used to be, this is a very easy S-meter to see.

When I received this receiver it barely worked.  As I started replacing the old wax capacitors, the local oscillator would come and go.  Sometimes it would work, and other times it would not.  I make it a habit to check the operation of the receiver after each capacitor is replaced.  It is much easier to fix a wiring problem as it happens, rather than realizing when all is done that there is a problem and then trying to find the error.  As I got deeper into replacing the caps in the IF section, the receiver began to get more stable in operation.  One of the paper capacitors actually had overheated and end of the cap was blown out.  This is testament as to why all old wax capacitors need to be replaced.  If they have not failed yet, they will.  I even removed the 2nd IF unit chassis off the main chassis to replace the wax capacitors in that chassis.  This required unwiring the 2nd IF chassis so it could be removed completely from the main chassis.  This was a lot of work, but I restore all my receivers to be very reliable and I want to use them regularly.  I replace all wax capacitors no matter how hard they are to reach.  My experience is that just about all the old wax capacitors are leaky.  Leaky capacitors will put a DC voltage where it does not belong, and this can be taxing on the power supply and other components.

I also replace the power supply electrolytics because of the potential catastrophic failure of the old electrolytics.  It is not worth the risk to leave them in operation even if the receiver works well and they seem to work fine.

I replaced the power cord, added an in-line fuse under the chassis, and installed an inrush current limiter.  Fuse protection on these older receivers is important to keep them from self-destructing f something should fail.

The only tube that needed to be replaced was the 6SC7 BFO and AF amp.  The AF amp section of the tube tested weak on a Hickok 750 tube tester.  The 6K6 audio output tube has been replaced at some time in the past.  It is common for the audio output tube to go bad before the other tubes.  All the other tubes appear to be the original Hallicrafters tubes.

Cosmetically the cabinet is in excellent condition.  The paint was very badly oxidized when I got it.  Once the front panel was removed and everything cleaned and the paint reconditioned, I found that the paint was actually in great shape.  The lettering on the front panel is remarkably good.  This receiver does not show the normal signs of wear such as the lettering being worn off from heavy use.

This is a fun receiver to use, but I find it a bit touchy on the main tuning.I  have to generally use the bandspread tuning to tune a shortwave station to the exact frequency.  The main tuning is just a bit too coarse.  The only other criticism I have of this receiver is the tuning feel.  It does not have a flywheel and it feels chintzy.

The S-76 picks up stations easily and in fact if I turn off the AVC it tends to overload even on weak stations.  I am using a 30-foot long wire antenna, which is probably why it tends to overload.

SSB reception is really not bad either.  If the AVC is turned off, the Sensitivity turned down, and CW mode selected it actually will pick up SSB fairly well.  The stability is pretty good for a receiver of this age.

I find the audio to be pleasant for single ended audio output.  It has enough audio power to sound strong without a lot of distortion.  Overall a nice vintage receiver.

Posted on March 21, 2010 - by Vintage Tube Admin

Hallicrafters SX-62A Communications Receiver

The Hallicrafters SX-62A is a high-end shortwave listeners receiver from the 1950s that includes the FM broadcast band.

I recently acquired this receiver and it is in remarkable condition.  It worked fine when I got it, but the sound was badly distorted.  The IF and RF sections were out of alignment.  I do not know the history of this receiver, but I’m convinced it was not used very much at all.  The front panel is in perfect condition.  The cabinet has been scratched and the finish damaged.  All of the tubes appeared to be the original Hallicrafters tubes.  The dial lamps are original and they still work.  I cleaned the chassis, replaced the line cord, installed an inrush current limiter, cleaned the switches and controls, and replaced paper and electrolytic capacitors.  There are three paper capacitors in the RF section that are extremely hard to get to for replacement.

There were some out of spec resistors in the audio output section that I replaced that helped clear up the audio distortion.

I changed the two 6V6 output tubes to new JJ Tesla tubes that I purchased in a matched set.  Push-pull audio output works best with matched output tubes.  The white “tube” in the rectifier socket is actually a solid-state rectifier replacement for the 5U4 rectifier tube.  I wanted to cut down the power transformer load and provide a more stable B+ voltage.  This saves about 15 watts of power.

Aligning one of these receivers is a major chore and takes a lot of patience.  The nice thing about it is the FM section can be aligned with a standard AM modulated signal generator because of the AM capability on all bands.  It took me several tries to get the crystal filter aligned.  The alignment instructions are a bit vague.

The cabinet has been professionally painted.

The SX-62A has an 8-ohm speaker connection so I connected a small bookshelf speaker directly to the 8-ohm output.

I really like the fact that I can listen to shortwave, AM broadcasts, and FM broadcasts on this receiver.  The push-pull audio is rated at 10 watts and the sound from this receiver is incredible!

This is not a DX’ing receiver.  It does not have SSB capability and is really not stable enough for DX work.  This is not why I got this receiver so it is of no concern to me.

This will definitely be a keeper for a long time.