#32194

The SX-10 is most likely the first hallicrafters with flywheel drive.? Radiomuseum has several photos of the insides showing the mechanism.? The SX-10 dial is the first to have an engraved dial of some 300+ degrees.? Looking at the SX-9 photos at the RM, it appears to have a direct drive so the 180 degree dial makes perfect sense.? I assume that the sets made before hallicrafters began production with the S-9 are also 180 degree dials?

The SX-10 set the standard for later production models.? The rumor is that only 200 were made but I think that there must have been more made then that.? Is this early trendsetter in anyone else's collection?

Jim

Logic: Method used to arrive at the wrong conclusion, with confidence.? Murphy

On Sunday, April 27, 2025 at 02:46:48 PM CDT, Bill (Group Owner) via groups.io <k2wh@...> wrote:

My SX-17 has direct tuning via a fly wheel.

?

K2WH

#32195

开云体育

Oh excellent Jim.? There the freewheel 'be' on the Radiomuseum underchassis view.? Great going!? The new winner at 1936 the SX-10.?

Now we have the first, the 1936 SX-10 and the last, the 1969 SX-146.? Any dissenters out there?

73
Don N9OO

On 4/27/25 11:59 PM, Jim Whartenby via groups.io wrote:

Show quoted text

The SX-10 is most likely the first hallicrafters with flywheel drive.? Radiomuseum has several photos of the insides showing the mechanism.? The SX-10 dial is the first to have an engraved dial of some 300+ degrees.? Looking at the SX-9 photos at the RM, it appears to have a direct drive so the 180 degree dial makes perfect sense.? I assume that the sets made before hallicrafters began production with the S-9 are also 180 degree dials?

The SX-10 set the standard for later production models.? The rumor is that only 200 were made but I think that there must have been more made then that.? Is this early trendsetter in anyone else's collection?

Jim

Logic: Method used to arrive at the wrong conclusion, with confidence.? Murphy

#32196
Edited

I have both an SX-10 and an SX-11 and the SX-10 does not have flywheel tuning (at least mine doesn't). ?I restored the SX-10 (pictured on top) some years back. ?The SX-11 just below it in the picture does have flywheel tuning so I am thinking it is the very first. ?It is circa 1937...

?

#32198

Never mind! ?My first picture is an SX-15 so the first I have with a flywheel is the SX-11. ?Probably the first with a flywheel is the SX-10...

?

I have too many silver dial radios so keeping track of the model number can be challenging!

#32199

开云体育

No problem Gary.? That's what makes these queries interesting.? The Hallicrafters books can't possibly answer it all and just a little investigative work goes a long way.? It's also nice seeing people craftsmanship work on these fine old radios.

73
Don N9OO

On 4/28/25 8:41 AM, Gary Schulz wrote:

Show quoted text

Never mind! ?My first picture is an SX-15 so the first I have with a flywheel is the SX-11. ?Probably the first with a flywheel is the SX-10...

?

I have too many silver dial radios so keeping track of the model number can be challenging!

#32200

So I decided to ask Gemini AI assistant the question about flywheel tuning in Hallicrafters receivers, how many had it.? The interesting answer is below.

While it's challenging to provide an exact count of all Hallicrafters shortwave receivers that featured flywheel tuning without access to a comprehensive historical database of every model and its specifications, we can identify several prominent examples known for this feature.

Based on available information, here are some Hallicrafters shortwave receivers that incorporated flywheel tuning for smoother operation:

?

?? Hallicrafters SX-28 "Super Skyrider": This is a well-known receiver and its tuning mechanism is described in detail, explicitly mentioning the use of heavy flywheels for both main tuning and bandspread. The design allowed for rapid spinning of the dial across the bands using the momentum of the flywheels.

?

??? Hallicrafters SX-28A "Super Skyrider": As a successor to the SX-28, it's highly likely that the SX-28A also retained the flywheel tuning system, as it was a highly regarded feature of the original.

?

??? Hallicrafters SX-88: This top-of-the-line receiver from Hallicrafters also featured gear-driven tuning knobs weighted with heavy flywheels, contributing to its smooth tuning feel.

?

1. Hallicrafters SX-88 and SX-99 - DXing.com

?

Source icon

www.dxing.com

??

? Hallicrafters SX-96: This model is described as having "smooth flywheel tuning," indicating its inclusion of this feature for ease of operation.

It's important to note that flywheel tuning was often a characteristic of higher-end communications receivers as it provided a more refined and user-friendly tuning experience compared to direct drive mechanisms. Therefore, it's plausible that other models in Hallicrafters' lineup, particularly those marketed as "Super Skyrider" or high-performance communications receivers, also included flywheel tuning.

?

The more basic or entry-level models, such as the Hallicrafters S-38 and S-120, are generally not noted for having flywheel tuning. Reviews of the S-120 specifically mention the lack of a flywheel and the effort required to tune across the bands. The service bulletin for the S-38 details the dial cord stringing without any mention of a flywheel.

?

To get a more precise number, a detailed examination of the specifications and features of each Hallicrafters shortwave receiver model produced would be necessary. However, the SX-28, SX-28A, SX-88, and SX-96 are confirmed examples of Hallicrafters receivers that utilized flywheel tuning.

K2WH

#32201

The S-20R was first built in 1939 I believe, so it is close.? Interesting history on these radios.

John WD5ENU

Show quoted text

On Mon, Apr 28, 2025 at 09:12 Gary Schulz via <mail=[email protected]> wrote:

I restored an SX-10 some years ago (pictured on top) and it does not have flywheel tuning.? The SX-11 on the bottom of the picture does have flywheel tuning so I am thinking it is actually the first- circa 1937

#32202

开云体育

Why does every one forget the SX 32 lol.

73 tony WA4JQS

On 4/28/2025 11:51 AM, Bill (Group Owner) via groups.io wrote:

So I decided to ask Gemini AI assistant the question about flywheel tuning in Hallicrafters receivers, how many had it.? The interesting answer is below.

While it's challenging to provide an exact count of all Hallicrafters shortwave receivers that featured flywheel tuning without access to a comprehensive historical database of every model and its specifications, we can identify several prominent examples known for this feature.

Based on available information, here are some Hallicrafters shortwave receivers that incorporated flywheel tuning for smoother operation:

?

?? Hallicrafters SX-28 "Super Skyrider": This is a well-known receiver and its tuning mechanism is described in detail, explicitly mentioning the use of heavy flywheels for both main tuning and bandspread. The design allowed for rapid spinning of the dial across the bands using the momentum of the flywheels.

?

??? Hallicrafters SX-28A "Super Skyrider": As a successor to the SX-28, it's highly likely that the SX-28A also retained the flywheel tuning system, as it was a highly regarded feature of the original.

?

??? Hallicrafters SX-88: This top-of-the-line receiver from Hallicrafters also featured gear-driven tuning knobs weighted with heavy flywheels, contributing to its smooth tuning feel.

?

1. Hallicrafters SX-88 and SX-99 - DXing.com

?

Source icon

??

? Hallicrafters SX-96: This model is described as having "smooth flywheel tuning," indicating its inclusion of this feature for ease of operation.

It's important to note that flywheel tuning was often a characteristic of higher-end communications receivers as it provided a more refined and user-friendly tuning experience compared to direct drive mechanisms. Therefore, it's plausible that other models in Hallicrafters' lineup, particularly those marketed as "Super Skyrider" or high-performance communications receivers, also included flywheel tuning.

?

The more basic or entry-level models, such as the Hallicrafters S-38 and S-120, are generally not noted for having flywheel tuning. Reviews of the S-120 specifically mention the lack of a flywheel and the effort required to tune across the bands. The service bulletin for the S-38 details the dial cord stringing without any mention of a flywheel.

?

To get a more precise number, a detailed examination of the specifications and features of each Hallicrafters shortwave receiver model produced would be necessary. However, the SX-28, SX-28A, SX-88, and SX-96 are confirmed examples of Hallicrafters receivers that utilized flywheel tuning.

K2WH

--
Anthony W.DePrato WA4JQS CQ DX HALL OF FAME #39 DXCC HONOR ROLL CW PHONE RTTY CALLS HELD VP8SSI VP8BZL V31SS 3Y0PI ZS8JQS WA4JQS/KC4 WA4JQS/ZS1

Virus-free.

#32203

开云体育

Since a ?day ?ago [this is a late reply] we deviated to non-Hallicrafters also, my old heathkit AR-3 had ?some kind of viscous damping tuning for each of the main and BS caps.

It is hard to believe how a slight torque will allow the Cap to turn very slowly. Just don’t lean down on the knob.

It can’t be a simple planetary gear reduction; perhaps it is a Jackson ball drive? which seems to be classed as one form of vernier drive. But I always wondered what is in there ????? .. I missed my education somewhere! ?

Show quoted text

From: [email protected] [mailto:[email protected]] On Behalf Of Richard Knoppow via groups.io
Sent: Sunday, April 27, 2025 7:55 PM
To: [email protected]
Subject: Re: [HallicraftersRadios] The First and Last Hallicrafters with Flywheel tuning?

?

There ete all sorts of variations of dial drives. For instance rhe Hammarlund SP 600 JX uses a gear reduction driven by a friction drive on the dial, it also has a flywheel. While it has both a main dial and band spread dial they are driven together. It is an extremely smooth drive.? In comparison, thr RCA AR 88 also has two dials which are driven together via gears but the main shaft is gear coupled to the dial mechanism, no friction drive. It also has a flywheel.? This is also a very smooth drive although the SP 600 is smoother.?

?

--
don??? va3drl

#32204

My National NC-183 (not 183D) has flywheels on main tuning and
bandspread tuning shafts.

73,

Maynard
W6PAP

Show quoted text

On 4/28/25 15:40, don Root wrote:

Since a ?day ?ago [this is a late reply] we deviated to
non-Hallicrafters also, my old heathkit AR-3 had ?some kind of viscous
damping tuning for each of the main and BS caps.

It is hard to believe how a slight torque will allow the Cap to turn
very slowly. Just don’t lean down on the knob.

It can’t be a simple planetary gear reduction; perhaps it is a Jackson
ball drive? which seems to be classed as one form of vernier drive. But
I always wondered what is in there ????? .. I missed my education
somewhere!

*From:*[email protected]
[mailto:[email protected]] *On Behalf Of *Richard Knoppow
via groups.io
*Sent:* Sunday, April 27, 2025 7:55 PM
*To:* [email protected]
*Subject:* Re: [HallicraftersRadios] The First and Last Hallicrafters
with Flywheel tuning?

There ete all sorts of variations of dial drives. For instance rhe
Hammarlund SP 600 JX uses a gear reduction driven by a friction drive on
the dial, it also has a flywheel. While it has both a main dial and band
spread dial they are driven together. It is an extremely smooth drive.
In comparison, thr RCA AR 88 also has two dials which are driven
together via gears but the main shaft is gear coupled to the dial
mechanism, no friction drive. It also has a flywheel.? This is also a
very smooth drive although the SP 600 is smoother.

--
don??? va3drl

#32206

In the book "Radios by Hallicrafters" () There are four occurrences of the word "flywheel".? The first is in the SX-16 article, the last occurrence is in the SX-146 article.

?