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 Post subject: Re: Hammarlund SP-600 JX-7 Restoration
PostPosted: Oct Fri 27, 2017 2:17 am 
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Location: Portage le Prairie, Manitoba
Mikeinkcmo wrote:
Speaking of wire, new, it isn't cheap at all, but at ham fests you see boxes of it under tables, begging for a sale. I always check em out, you never know what you might find for a buck or two.


That's true. It's been ages since I went to a ham fest.

I've been poking around in the actual electronics side of things here. Trying my best to straighten things up a bit. That's more or less my plan, straighten things up, check wiring, recap and reinstall RF section, rewire power supply section and then power up test. Said power up test should be a few months from now at this rate.

Taking a closer look at things has only made me confused. I am no longer sure that this is a JX-7, and I am relatively sure that I have purchased the wrong manuals. It's starting to look more like a JX-21 with some extra factory punched holes in it. I'll have to look into the wiring more to figure things out. My head hurts...

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 Post subject: Re: Hammarlund SP-600 JX-7 Restoration
PostPosted: Oct Fri 27, 2017 3:49 am 
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Mine had several modifications as well some of which made no sense, so I just went through the entire receiver, pulled everything that wasn't stock X17, then I changed the AGC to reflect the version Les said was the best one. The X10 I think, its been a while.

I bought the TM11-851 probably the most inclusive of all the manuals and tons of text regarding nearly every facet of the receiver. I also bought Hammarlund's 600 manuals, and printed the anthology, which is the most comprehensive collection of modifications for the 600.

I just started in the power supply side and just went all the way around the chassis.

Image

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 Post subject: Re: Hammarlund SP-600 JX-7 Restoration
PostPosted: Oct Fri 27, 2017 12:44 pm 
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Location: Portage le Prairie, Manitoba
Mikeinkcmo wrote:
Mine had several modifications as well some of which made no sense, so I just went through the entire receiver, pulled everything that wasn't stock X17, then I changed the AGC to reflect the version Les said was the best one. The X10 I think, its been a while.

I bought the TM11-851 probably the most inclusive of all the manuals and tons of text regarding nearly every facet of the receiver. I also bought Hammarlund's 600 manuals, and printed the anthology, which is the most comprehensive collection of modifications for the 600.

I just started in the power supply side and just went all the way around the chassis.


It looks like that is what I will be doing as well. It's gonna be tedious.

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 Post subject: Re: Hammarlund SP-600 JX-7 Restoration
PostPosted: Oct Fri 27, 2017 2:10 pm 
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A couple tips.

1. If more bass response is desired replace the two audio coupling caps with caps twice their value.
2. If more audio output is desired the 600 ohm output can directly drive a pair of 6V6 or 6BQ5 tubes or any other tube with similar grid drive voltage requirements and you install a 500 ohm 1 watt resistor on each control grid to ground to provide some sort of load for the output transformer.


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 Post subject: Re: Hammarlund SP-600 JX-7 Restoration
PostPosted: Oct Sun 29, 2017 3:33 am 
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Thanks for the info, Tube Radio. I'll likely leave things spec until I get the radio working, then I'll see how she sounds. I'm sure I'll be happy with the output power. I would use an external amp if I wanted more. Not sure about the fidelity though. I hear the SP-600 doesn't have as warm a sound as some other boat anchors. A much more limited dynamic range by design, so I've read.


Well, I have started the recapping process following the second schematic in the Issue 4 manual. This schematic applies to the JX-21, JX-26 and perhaps a few other direction finder type receivers. My receiver is certainly the direction finder type seeing as it has the rectangular block type E13 with the two screw terminals to change the AVC. I've been checking the wiring as I go.

That section forward of the power supply has been recapped as well as the small can on the side of the band turret/tuning capacitor section.

Image

The brown capacitor on E13 is C100 which is present on the layout diagram but is not shown on the schematic or the parts list. :?

Three of the four resistors on E13 are out of spec. The two 1.5M resistors measure 990K and the 1M resistor measures 770K. I'm not particularly happy with those numbers, so I will likely replace those next. I'm rather short on higher wattage resistors though. I mostly have 1/4 watt metal film and carbon film types. I'd prefer too use larger metal oxide types, but they're not cheap!

The capacitors I'm using to replace the black beauties are Panasonic metal foil types 630 volt rated, 5% tolerance. I happen to have 500 of them, so they seemed like a good choice! Here's what they look like:

Image

The original black beauty capacitors appear to have the outside foil lead marked with a drop of solder. This lead then appears to be connected to the lower impedance part of the circuit in order to offer some shielding from hum. I'm doing the same with my capacitors, however, I do not have the luxury of having them marked by the factory. I have to do that part myself.

For that I use my Tektronix 453 with a BNC cable terminated in clip leads. I'm sure some of you have heard of this method before, but in case someone hasn't and since I love to talk, I'll explain it! :P

With the capacitor in my fingers and connected to the clip leads and with the scope on the lowest Volts/Div setting, any hum picked up by my body will appear on the scope, usually a nice clean 60Hz signal. Changing the clip leads back and forth should change the amplitude displayed on the scope. When the amplitude is higher, the signal lead is connected to the outside foil side and when it is lower, the ground lead is connected to the outside foil side.

I find that there is not a lot of stray noise here, so I held an AC cord (the insulated jacket of course) in one hand and the capacitor between my thumb and index finger of the other hand to increase the amplitude for the pics. I imagine a signal generator could be used in the same manner to apply a signal to my body and then pass it to the capacitor.

Here are some pics showing the difference in amplitude. I just love oscilloscopes! Older is better! :D

Image

Image

The black line on the side of the capacitor in the picture is permanent marker. Once I know which side is the outside foil, I mark it then do the next one. It's monotonous, but I enjoy it. I feel like I'm in some old factory testing components on a production line.

I hope everyone following along likes reading! I'm pretty good at rambling on.

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 Post subject: Re: Hammarlund SP-600 JX-7 Restoration
PostPosted: Oct Sun 29, 2017 3:41 am 
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towble wrote:
The original black beauty capacitors appear to have the outside foil lead marked with a drop of solder.
That's correct:

Image

- Leigh

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 Post subject: Re: Hammarlund SP-600 JX-7 Restoration
PostPosted: Oct Sun 29, 2017 5:44 am 
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The SP-600 JX-17 didn't sound very warm to me until i replaced the two audio coupling caps with ones twice their value.

Then with a vintage wall mount jukebox speaker with 10' driver it sounds quite warm.

The amp itself has the added benefit of better sound quality even if you don't need need for instance 10 watts of audio.

I do agree with getting it working properly first.

Also from experience I know the SP-600 series (I own a JX-17) is known to operate quite well on weak tubes so they will need to be tested.


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 Post subject: Re: Hammarlund SP-600 JX-7 Restoration
PostPosted: Oct Sun 29, 2017 12:10 pm 
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I like your choice in scopes.

Image

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 Post subject: Re: Hammarlund SP-600 JX-7 Restoration
PostPosted: Oct Sun 29, 2017 5:32 pm 
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Joined: Dec Mon 31, 2012 11:09 pm
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Location: Portage le Prairie, Manitoba
Mikeinkcmo wrote:
I like your choice in scopes.


Thanks! I like your choice in vintage HP volt meters! I have a 400EL myself.

I own five oscilloscopes. One Tektronix 453, one HP 1740A (that doesn't trigger very well), two HP 182T mainframes, one with an 8557A spectrum analyser plug in and the other is an extra, and one B&K 1476 that works, but I've never actually used. I really like the HP 180 series scopes. I'd like to get an AN/USM-281 at some point. I just think they look great!

Tube Radio, yeah, I've heard that the SP-600 doesn't have the warmest sound. I may end up modifying it a bit in the end.

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 Post subject: Re: Hammarlund SP-600 JX-7 Restoration
PostPosted: Oct Mon 30, 2017 12:21 am 
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Never had any HP scopes, but I had a room full of Tek scopes and plug-ins once upon a time, but only 2 now. The 454 and a 2465. I do have a 141T and most everything to go with it, nice to have once in a while.

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 Post subject: Re: Hammarlund SP-600 JX-7 Restoration
PostPosted: Oct Mon 30, 2017 12:33 am 
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I had the chance to get an older HP scope almost two years ago, but I remembered that HP CRTs are harder to find so I passed.


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 Post subject: Re: Hammarlund SP-600 JX-7 Restoration
PostPosted: Nov Wed 01, 2017 5:48 pm 
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Location: Portage le Prairie, Manitoba
I got some supplies in the mail a few days ago and had the opportunity to try my hand at making a turret board for the first time. I am quite pleased with how things went.

I used 1/8" Garolite in a red color that I thought would blend well with the brown turret board E13 in my receiver. The Garolite was purchased from Tube Depot and the turrets are from Antique Electronic Supply. They are for 3mm boards, so they protrude a bit from the back. I drilled the holes then filed them out to give a reasonably tight fit once the turrets were lightly tapped in place. I then used a homemade staking tool to expand them a bit and lock them in place.

Image

The board holds the three filter capacitors.

Image

I installed the turret board between the filter chokes using the original filter capacitor brackets that I modified slightly.

Image

The staking tool was made from 3/8" steel round stock that I had lying around. I chucked it up in the lathe and turned the diameter down to about 1/8" then cut a slight taper.

Image

I spent $3000 on a combination lathe/milling machine about a year ago now. I haven't done enough on it to justify the cost, but it sure is handy to have! You know, for when I need to use a $3000 tool to make my own $5 tool! :P

I used my drill press as an arbor press to stake the turrets. I'm thinking I may try a two step process next time using the slight taper to enlarge the turrets in their holes, then a wider 45 degree taper to flare them where they protrude.

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 Post subject: Re: Hammarlund SP-600 JX-7 Restoration
PostPosted: Nov Wed 01, 2017 7:22 pm 
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Nicely done, I like it.

At first I thought there wouldn't be enough vertical clearance topside, but removing the converters would allow the inductors to be mounted on the plane of the main chassis.

I'd like to have some metal working tools/machines but thers's just not enough room. The woodworking tools, and wire n stick welders take up all the space.

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 Post subject: Re: Hammarlund SP-600 JX-7 Restoration
PostPosted: Nov Wed 01, 2017 10:12 pm 
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Joined: Dec Mon 31, 2012 11:09 pm
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Location: Portage le Prairie, Manitoba
Mikeinkcmo wrote:
Nicely done, I like it.

At first I thought there wouldn't be enough vertical clearance topside, but removing the converters would allow the inductors to be mounted on the plane of the main chassis.

I'd like to have some metal working tools/machines but thers's just not enough room. The woodworking tools, and wire n stick welders take up all the space.


Thanks, Mike! And yes, the chokes are mounted on the main chassis and it does give me a lot more room underneath. I prefer it that way as it doesn't obscure any of the other components that could be difficult to get to when the chokes are mounted on the usual sunken plate.

As for my machine tools, having a combination machine makes things a lot more compact. The unit only takes up about ten square feet of work space. Which is good seeing as I'm situated in a small basement. My brother's basement at that, meaning I'll have to move the 540lb beast back up the stairs at some point.

Image

I'd like to get a welder at some point. I've always thought that may be the way to go for custom racks in the future.

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 Post subject: Re: Hammarlund SP-600 JX-7 Restoration
PostPosted: Nov Wed 01, 2017 11:56 pm 
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Towble said,
Quote:
I'd like to get a welder at some point. I've always thought that may be the way to go for custom racks in the future.
I welded up my own equipment racks for my test/repair bench a couple years ago using rack uprights from parts express or similar, and some 1/2" angle. You can get 5ea 19" bays on a 96" bench.

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 Post subject: Re: Hammarlund SP-600 JX-7 Restoration
PostPosted: Nov Thu 02, 2017 12:41 am 
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Joined: Dec Mon 31, 2012 11:09 pm
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Location: Portage le Prairie, Manitoba
Mikeinkcmo wrote:
I welded up my own equipment racks for my test/repair bench a couple years ago using rack uprights from parts express or similar, and some 1/2" angle. You can get 5ea 19" bays on a 96" bench.


I thought of doing something similar using pre-made uprights. That's fantastic work, Mike! I hope to have as neat a setup as that some day!

You seem to be a fan of HP equipment, I certainly get that. Also, it took me a few looks to see it, but I have that same RC plane! It's sitting right next to my large work bench. I've never flown it. The time has just never been right. It's usually too windy here.

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 Post subject: Re: Hammarlund SP-600 JX-7 Restoration
PostPosted: Nov Thu 02, 2017 2:21 am 
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towble wrote:
Image

Sweet!

Where did you get that? Can I get one? :D


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 Post subject: Re: Hammarlund SP-600 JX-7 Restoration
PostPosted: Nov Thu 02, 2017 2:47 am 
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Location: Portage le Prairie, Manitoba
Sol wrote:
Sweet!

Where did you get that? Can I get one? :D


Well depending where you're located, you may have a local machine tool supplier. I did not, so I ordered mine online from Travers Tool Company and had it shipped to my door from the US. It's Chinese made, so it's not quite to the standards of the old American made machine tools, but it's not too bad. There are all sorts of machine tool suppliers out there that stock similar units.

Keep an eye out for the old machines too. There are plenty of lathes and mills out there some as old as 1950s that are still solid units and will work well after a little clean up and alignment.

Machining has always been a fascinating skill that I hope to learn more and make use of in the future. So far, I've just made a few small things. Mostly punches, swages, and the like. But it certainly is enjoyable to make a tool from scratch then use it.

I also plan to try turning various radio parts at some point. Stand offs, shaft extensions, couplers, knobs, etc. I'd also love to make a custom straight Morse key from solid brass! :D

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 Post subject: Re: Hammarlund SP-600 JX-7 Restoration
PostPosted: Nov Thu 02, 2017 2:54 am 
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towble wrote:
Keep an eye out for the old machines too. There are plenty of lathes and mills out there some as old as 1950s that are still solid units and will work well after a little clean up and alignment.

I'm a master tool & die maker, and own a full commercial machine shop.

My primary mill (Bridgeport) and lathe (Monarch 10EE) were both manufactured in 1957.
They both still meet all original specs. I have no problem turning out quality work with them.

- Leigh

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 Post subject: Re: Hammarlund SP-600 JX-7 Restoration
PostPosted: Nov Thu 02, 2017 3:05 am 
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Leigh wrote:
I'm a master tool & die maker, and own a full commercial machine shop.

My primary mill (Bridgeport) and lathe (Monarch 10EE) were both manufactured in 1957.
They both still meet all original specs. I have no problem turning out quality work with them.

- Leigh


It's the same reason I'm restoring a radio from 1952 and most of my test equipment is from the 70s or earlier! They just don't make them like they used to! Even my shop phone is circa 1940!

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