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Re: HA-1 T.O. Keyer socket gnds
开云体育We sometimes forget that a chassis is often a high-current AC conductor, sometimes carrying several amps of tube heater current.? To Don’s comment, bonding to a single common chassis point often reduces or eliminates induced hum and buzz.? ? Someone mentioned using balanced heaters and a hum control balancing pot.? That’s excellent advice, but during production, manufacturers would typically wire the heater bus first, then overlay additional wiring like laced cable harnesses.? In many transceivers with dense wiring practices, it’s a real challenge to replace heater wiring with a twisted pair without disrupting components and existing wire runs, even if attempting an overlay.? I once tried to balance a Collins KWM-2A’s heather string but gave up: a point was reached where collateral damage started to occur owing to under-chassis packaging density.? ? On a positive note, I replaced the AF amps in my Drake R-4B and R-4C receivers.? The goal was to get hum/buzz down to zero with the AF control wide open.? With a screwdriver connected to the AF amp’s ground lead, I wiped across the chassis in search of the lowest hum/buzz level.? I found several points that met this criteria.? Once found, a hole was drilled in the chassis and a solder lug added for the ground connection. ?At these points, AC heater ground current is minimal, sometimes cancelling altogether.? ? Paul, W9AC ? ? From: [email protected] <[email protected]>
On Behalf Of Don Buska - The Radio Lab Works
Sent: Sunday, May 4, 2025 8:26 AM To: [email protected] Subject: Re: [HallicraftersRadios] HA-1 T.O. Keyer socket gnds ? On 5/4/25 2:31 AM, haywireman via groups.io wrote:
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Re: HA-1 T.O. Keyer socket gnds
开云体育Don, John, ???does the “common ground return” mean any old connection to a “ground wire” scheme, or is it a specifically designed wiring scheme ? ? From: [email protected] [mailto:[email protected]] On Behalf Of Don Buska - The Radio Lab Works
Sent: Sunday, May 4, 2025 8:26 AM To: [email protected] Subject: Re: [HallicraftersRadios] HA-1 T.O. Keyer socket gnds ? On 5/4/25 2:31 AM, haywireman via groups.io wrote:
_._,_._,_ -- don??? va3drl |
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Re: HA-1 T.O. Keyer socket gnds
开云体育On 5/4/25 2:31 AM,
haywireman via groups.io wrote:
I have read several times that it is a "best practice" to wire every point directly to a common ground return on the chassis Hey John,? That's a very common practice in audio gear, naturally, to avoid ground loops. 73 Don N9OO |
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Re: HA-1 T.O. Keyer socket gnds
Yes!? I have even wondered if soldering socket ground terminals to the chassis is enough to ensure good performance.? Solder is not the perfect conductor, and does not have the best strength or immunity to fracturing over time.? I have read several times that it is a "best practice" to wire every point directly to a common ground return on the chassis, but have never seen it done in practice, except maybe in some Collins equipment. John
On Saturday, May 3, 2025 at 10:40:58 AM CDT, Jim Whartenby via groups.io <old_radio@...> wrote:
Chassis grounds that use rivets is an ongoing problem.? Whenever there is a weird problem, like an alignment issue, I routinely solder the tube socket ground terminals and other ground tie points to the chassis as a first effort to resolve the problem.? This saves a lot of troubleshooting time and is good excuse to keep that old American Beauty 100 watt soldering iron in the toolbox. Jim Logic: Method used to arrive at the wrong conclusion, with confidence.? Murphy
On Friday, May 2, 2025 at 04:51:11 PM CDT, waltcates via groups.io <cateswa@...> wrote:
I have seen center post to ground as high as 150 ohms. It only takes 3 to 5 ohms to start causing problems with speed and weight. It has the biggest effect on the timing capacitors.
Walt Cates, WD0GOF
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A majority of acceptance is not proof of correctness.
From: [email protected] <[email protected]> on behalf of Floyd - K8AC via groups.io <floydsense@...>
Sent: Friday, May 2, 2025 2:41 PM To: [email protected] <[email protected]> Subject: Re: [HallicraftersRadios] HA-1 T.O. Keyer ?
Very good, Walt.? Glad to see you point out the problem with the tube socket grounds.? Years ago my HA-1 became erratic - code elements missing or the wrong length.? It took me many days before I discovered a faulty ground at a tube socket - it looked
perfect but must have had a high resistance.??
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73, Floyd - K8AC
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Re: Working on HT-32B & Weight Lifting
开云体育shipping weights overseas? or bare bones weights? ? From: [email protected] [mailto:[email protected]] On Behalf Of Scott Petersen via groups.io ? Wow! 125lbs!? found 3 different weights for the R390, I don't know which is correct, 65# 75# and 85# unless there are differemt sub models...
-- don??? va3drl |
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Re: HA-1 T.O. Keyer socket gnds
Chassis grounds that use rivets is an ongoing problem.? Whenever there is a weird problem, like an alignment issue, I routinely solder the tube socket ground terminals and other ground tie points to the chassis as a first effort to resolve the problem.? This saves a lot of troubleshooting time and is good excuse to keep that old American Beauty 100 watt soldering iron in the toolbox. Jim Logic: Method used to arrive at the wrong conclusion, with confidence.? Murphy
On Friday, May 2, 2025 at 04:51:11 PM CDT, waltcates via groups.io <cateswa@...> wrote:
I have seen center post to ground as high as 150 ohms. It only takes 3 to 5 ohms to start causing problems with speed and weight. It has the biggest effect on the timing capacitors.
Walt Cates, WD0GOF
?
A majority of acceptance is not proof of correctness.
From: [email protected] <[email protected]> on behalf of Floyd - K8AC via groups.io <floydsense@...>
Sent: Friday, May 2, 2025 2:41 PM To: [email protected] <[email protected]> Subject: Re: [HallicraftersRadios] HA-1 T.O. Keyer ?
Very good, Walt.? Glad to see you point out the problem with the tube socket grounds.? Years ago my HA-1 became erratic - code elements missing or the wrong length.? It took me many days before I discovered a faulty ground at a tube socket - it looked
perfect but must have had a high resistance.??
?
73, Floyd - K8AC
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Re: Working on HT-32B & Weight Lifting
I checked the manuals for the various versions of the R-390: R-390????????TM 11-856????????80 pounds R-390A????? TM 11-856A? ? ?75 pounds R-391? ? ? ? TM 11-863? ? ? ? 82.5 pounds Jim Logic: Method used to arrive at the wrong conclusion, with confidence.? Murphy
On Saturday, May 3, 2025 at 06:42:34 AM CDT, Scott Petersen via groups.io <s-petersen@...> wrote:
Wow! 125lbs!? found 3 different weights for the R390, I don't know which is correct, 65# 75# and 85# unless there are differemt sub models...
From: [email protected] <[email protected]> on behalf of n7qmm25 <n7qmm25@...>
Sent: Friday, May 2, 2025 10:48 PM To: [email protected] <[email protected]> Subject: Re: [HallicraftersRadios] Working on HT-32B & Weight Lifting ?
What are you youngsters crying about any way. HT9 @ 125 lbs. I have 4 of them, 2 old model and 2 new model. On 5/2/2025 4:25 PM, Scott Petersen via groups.io wrote:
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HT-32B SSB Generator - Removed
开云体育Well I went ahead and tackled the removal of the HT-32B SSB Generator Sub-Chassis.?? Not as bad as I thought it would be.It came out relatively easy.? I had one 1/4" head machine screw that was holding the rear left corner of the SSB Generator in place and it was so close to the Power Transformer I couldn't get a nut driver on it.? A wrench was out of the question since that screw was in a small space between the unit and the side wall of the rig.? I was lucky and I could loosen the four nuts holding down the transformer and move it over slightly to just get one of my nut drivers on it. The meter remains in place on the front panel and I simply removed the wiring terminals that went to it.? The MIC connector also remains attached to the front panel.?? So the front panel is only tilted forward and lays on a towel on the bench. The Meter Compression potentiometer bracket assembly is also removed from the front side of the Generator sub-chassis.? It has no wires that go to the Generator, only wires to the meter and one going under to the main chassis. Here is the SSB Generator removed with the cover off. You can see the dual 10uF 350V Electrolytic (C7) on the right side.? I will replace C7.? Of equally great importance is the fact I see two of the ever famous Bumble Bee caps in the upper center.? Those along with another three on the main chassis will see mandatory replacement! Overall I am happy I removed this subchassis.? I will replace those mandatory components mentioned and get everything back together ASAP.? I don't want to leave the transmitter siting without the front panel for to long.? The goal is do the electrical work, some cleaning and back in place before addressing the main transmitter chassis work. This is the only picture of the inside of the HT-32B's SSB Generator that I've seen outside the small B&W version in the Hallicrafters manual. Enjoy es 73 Don N9OO |
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Re: Working on HT-32B & Weight Lifting
开云体育What's one pound amongst friends, hi.73? Don N9OO On 5/2/25 19:32, thoyer via groups.io
wrote:
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Paul Christensen
don Root
Don Buska - The Radio Lab Works
haywireman
Jim Whartenby