Hallicrafters SX Serial Number H Here is the SX, as received. Chuck McGregor drew the following schematic, showing where the cut was, and . View and Download Hallicrafters SXA technical manual online. SXA Radio pdf manual download. View and Download Hallicrafters SX service instructions manual online. The Model SX Super Skyrider Receiver. SX Receiver pdf manual.
|Country:||Moldova, Republic of|
|Published (Last):||23 March 2014|
|PDF File Size:||4.14 Mb|
|ePub File Size:||12.22 Mb|
|Price:||Free* [*Free Regsitration Required]|
No other communications receiver, even those that are better performers, has such a dedicated following. Certainly, the SX’s top performance that combines great audio with an impressive appearance is responsible for the enthusiasm of its fans. Serial number analysis and a serial number log along with a chronological listing of Engineering Upgrades provides tools for accurately dating your receiver. Today, hundreds and hundreds of SX receivers have been restored and are in use in Vintage Ham Shacks around the country still providing great performance with incredible, bass-rich audio.
The SX remains one of the most popular of the “pre-war masterpieces. The receiver’s ultimate design was the result of the analysis of more than requested reports, including input from government engineers. Twelve Hallicrafters’ engineers were assigned the project of creating a receiver that not only satisfied government and commercial users but also gave the hams a receiver that performed better than any previous Hallicrafters.
Additionally, the SX’s modern, styling was to compliment the receiver’s great performance. The circuit utilized 15 tubes in a double preselection front-end on the top four bands and single preselection on the lower two bands. The frequency coverage was. The SX would hallicraffters an all-time ham favorite, famous for incredible audio coupled with amazing sensitivity, stability and selectivity – all at a reasonable selling price.
Shown to the left and below are pages two, hallicrrafters and four of the multi-page advertisement in July QST that announced the SX Page one of the ad states that the SX was “, Typical of a new product advertisement, conceptual artwork is used rather than actual photographs.
Oddly, the ad states that the Super Skyrider is a 14 tube receiver but this is more than likely just an error from the advertising department. The first few production runs of the SX receivers have a several differences from the later production units.
SX SN H left the Hallicrafters’ plant on October 29, – about two months after the SX introduction and most likely from the second production run. It has most of the characteristics of the first SX receivers, e.
I totally rebuilt this SX and the performance is incredible. H with matching R floor speaker. This was the Hallicrafters-Jensen R There were actually three speakers available from Hallicrafters that were compatible with the SX The PM – a 10″ table speaker – was standard.
Also available was the Jensen-Hallicrafters R-8, an eight inch speaker in a small bass-reflex cabinet. The largest speaker-cabinet available was the R The R speaker-cabinet utilizes sx-2 wide-range 12″ Jensen PM speaker with a ohm Z matching transformer to hallucrafters the audio output of the SX The R cabinet is made up of five panels that clamp together using internally mounted clips.
The back of the speaker screws in place and seals the cabinet except for the bass reflex port. The wood used is a soft lumber core that has a soft wood veneer. Rs were painted a dark silver-gray, Hallicrafters called it “gunmetal,” and the decorative incised arch was filled with red paint.
Hallicrafters SX-28 Service Instructions Manual
Originally, the wire screen grilles were flocked with a champagne colored mohair but this seldom survives today. Rs were only available from late up to the beginning of WWII, which accounts for their rarity today.
Fred had acquired the combination from Woody Woods’ son after it had been discovered, stored in Woods’ basement, in Auburn, California.
I totally rebuilt the SX Fortunately, it was “dead-stock” with no modifications and the receiver had only one serious problem. This was an unusual problem of very low gain caused by a broken powdered-iron slug in T-3 last IF transformer. I replaced T-3 with a good condition unit from a “parts set” SX The R was in pretty “rough” condition with peeling veneer and warped panels.
All of the panels needed to be wetted and then clamped to straighten them. After the panels were straight and dry, I had to reglue the veneer and add some patches where the veneer was missing. I matched the paint by removing the “h” grille and using the “unfaded” paint that was protected by its mounting as the color sample.
Performance of the SX with the R is fabulous. Although several other pre-war communications receivers have audio output stages that can rival the SX, there is a certain appeal to listening to a receiver with such dramatic presence as the SX, especially when used with the R speaker. Want to build a replica R speaker? I took this R apart and photographed the interior in detail.
I also measured all of the important dimensions and described the types of materials used in the original construction. Phil Nelson of “Phil’s Old Radios” has edited and hosts the article on his website. Here’s a link to the article: Build Your Own Hallicrafters R The photo right is H, a mid production SX, showing the typical chassis layout.
Of note is the power transformer which has the standard Hallicrafters’ “h” embossed on the cover. The glass tubes in front of the power transformer are the rectifier 5Z3 and the two 6V6 push-pull audio output tubes. The BFO section is to the right of the 6V6s. S-meter amplifier, first audio, detector and the last IF transformer for the sections across the front part of the chassis. This is the standard condenser box cover found on all SX receivers up to late The “spotty” chassis is typical of cadmium-plated steel when exposed to light moisture.
It was first introduced in for use with the SX and was still available through The 10″ Jensen speaker has a ohm to 8 ohm transformer to match the speaker to the typical Hallicrafters’ audio output impedance. The chrome “h” was installed on all PM speaker grilles until about when it was discontinued for the duration of WWII. At about the same time, the magnet cover was eliminated from the speaker frame. Most speakers are dated in some manner – ink-stamped on the frame or cone is most common.
PM speaker photo right: I purchased the receiver from John, who was 85 at the time and living in Galena, Nevada.
John stated that the SX was “, Internally, the receiver has the redesigned Lamb ANL circuit and the bandspread dial is driven by a dial string. Although H left the Hallicrafters’ plant in Februaryit was actually civilian purchase. Having seen hundreds of SXs over the years, I am fairly sure that H is probably one of the best condition, original receivers to have survived.
It is all original parts with the exception of the S-meter load resistor. It has its original warranty card, the original inspection tag, the original bottom cardboard cover and the original manual. John kept his receiver in a “dark” room usually the curtains were uallicrafters during the day and only a small desk lamp provided light. This lack of bright light and John’s meticulous care has preserved H in an exceptional original state. During the sx–28 part of the SX wartime production, some versions were built with heavy-duty parts and other changes that were certainly at the request of the Navy and the Signal Corps.
These heavy-duty SX receivers have a General Transformer Company power transformer that is potted, Korite dipped filter choke and audio output transformer and also feature the return to the gear-driven bandspread tuning. The Navy versions sometimes have different front panels that are wrinkle finish with a military tag in place of the ” the hallicrafters inc.
These heavy-duty SX receivers are hallivrafters rack mount configuration. When the SXA was introduced in early probably April, some of the first production SXA receivers were produced in the heavy-duty configuration. Also included was the heavy-duty gear-driven bandspread dial that had been used in the early pre-war SXs. The chassis wiring uses military type stranded wire with white cloth insulation.
Maurizio reports that the MFP date stamp is May 27, It is also interesting that only serial numbers were mannual in a 16 day period indicating that production that used hallicraftets “HA” prefix was fairly low at this time.
The span of serial numbers from HA to HA is numbers. Much of the R circuitry and design was borrowed hlalicrafters from the SXA.
However, since the receiver was primarily for search and surveillance, a motor drive tuning was provided for automatic scanning of operator set frequencies with reverse direction switching provided at each end limit of the tuning scan. The receiver also provided Panadaptor and Video Outputs that were designed to feed into specific airborne versions of typical panoramic adapters and oscilloscopes. The oscilloscopes sometimes had built-in oscillators to create lissajous patterns for audio analysis of incoming signals Video output is from the 6V6 audio stage of the receiver.
The lissajous patterns based on the oscillator input allowed the operator to measure radar pulse rates and thus identify the particular type and origin of the signal.
The panoramic adapters monitored the output of the Mixer stage of the receiver and provided a visual representation of the spectrum surrounding the receiver’s IF passband. This allowed the operator to “see” signals that were outside the receiver’s passband and couldn’t be heard. But they could be seen on the panadapter thereby alerting the operator to tune to the signal for further investigation.
The R’s circuit is very similar to the SXA, although it is “stripped down” to the essentials and considerably lightened for aircraft use. The R uses 12 tubes not counting the rectifier located in the PP power pack and has six tuning ranges.
Some of the similarities to the SXA include using the same Micro-set coils in the front end and providing six selectivity steps, three of which utilized the crystal filter. The main circuit differences from the SXA include the use of a VT voltage regulator tube the SXA didn’t use any VT voltage regulation, using a 6SK7 1st RF amplifier tube the SXA used a 6AB7, using a 6AB7 “re-radiation” tube to prevent LO leakage to the antenna, the Noise Limiter which is just a clipper circuit instead of the fabulous Lamb Noise Silencer, no bandspread provided and the “militarily” basic audio output system which is just a capacitive coupling from the 6V6 plate to drive the headphones.
The audio output of the R is really only for headphones but a ohm speaker system will provide ample volume even though the audio quality is considerably inferior to the SXA. Additionally, the PP operated off of vac cycle provided by the aircraft’s ac system. Other contractors included Belmont Radio Corporation. The R shown in the photo is from and was built by Hallicrafters. It is mounted on the original aircraft shock mount.
The R receivers do not use the standard Hallicrafters serial number metal tag and do not use the HA serial numbers.