HT-44 rough CW note in transceive mode
I was checking out the HT-44 operating in transceive mode on CW with the SX-117 this evening.? Monitoring on a separate receiver, I see and hear that the CW note is rough.? If I operate in "normal" or separate mode, the CW note is pure.? I wonder if that's normal for this pair???
73, Floyd - K8AC
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There is a little more?information on the 32 and 37 at:?
Walt Cates, WD0GOF
?
A majority of acceptance is not proof of correctness.
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Good Stuff, thanks very much!
wa3gin
That is the test point used to set the bias (PA idle current). See section 4-10 of the factory manual.
For a helpful mod for adjusting idle current see:?
Walt Cates, WD0GOF
?
A majority of acceptance is not proof of correctness.
My 32A has a test point located near the 6AB4 tube in the front of the chassis.? What does it test?
Thanks-George KN3PAT
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if it drifts still after 6 hrs? i would look for a bad mica cap in
the vfo also.
73 Tony wa4jqs
At 01:30 PM 6/30/2024 -0700, you wrote:
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No, I have not checked that. I will
check it when I pull it apart.? Adding it to my list! Even after its
been on for maybe 6 or more hours it still drifts.
Anthony W.(Tony) DePrato
WA4JQS Extra Since 1962
CQ DX HALL OF FAME #35
HONOR ROLL CW RTTY PHONE
#1 MOST WANTED VP8SSI 1992
#1 MOST WANTED 3Y0PI??? 1994
Founder :South Sandwich Island DX Group
Founder : Ky Dx Group WA4LLK 1988
Founder: Lake Cumberland Amateur Radio Assoc. 1974
Calls Held: VP8SSI VP8BZL 3Y0PI
???????????????? V31SS ZD8JQS WA4JQS/4K1
????????????????? WA4JQS/KC4 WA4JQS/ZS1
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No, I have not checked that. I will check it when I pull it apart.? Adding it to my list! Even after its been on for maybe 6 or more hours it still drifts.
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i had the SX 101A version and never had any drift problems the 101 may
have been different but can not recall hearing it was a problem. did you
check the heater resister ? it is across the AC line and keeps the
filaments lit to stop any VFO drift. i think the 101 may have also had
this.
73 Tony WA4JQS
At 06:57 AM 6/30/2024 -0700, you wrote:
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My 101 drifts, and from what I read
is a common problem.? I see several possible cures for it. 1) VFO
because it has a drift correction adjustment that is simple to
manipulate. This from a post on 2/2015.? I can't find any info on
this adjustment?? Where is that adjustment located and how do you do
it?
2)Re-cap it.? I dread the thought of working on this beast.?
But does anyone recommend a good re-cap kit?
3)Replace the 6c4 with a 7 pin pentode?? Any recommendations on the
pentode.? Is this an easy "drop in" replacement?
I use this receiver along with my HT-32A.? A lot of enjoyment, even
with the drift!
Thanks for the help!
George-KN3PAT
Anthony W.(Tony) DePrato
WA4JQS Extra Since 1962
CQ DX HALL OF FAME #35
HONOR ROLL CW RTTY PHONE
#1 MOST WANTED VP8SSI 1992
#1 MOST WANTED 3Y0PI??? 1994
Founder :South Sandwich Island DX Group
Founder : Ky Dx Group WA4LLK 1988
Founder: Lake Cumberland Amateur Radio Assoc. 1974
Calls Held: VP8SSI VP8BZL 3Y0PI
???????????????? V31SS ZD8JQS WA4JQS/4K1
????????????????? WA4JQS/KC4 WA4JQS/ZS1
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The plate voltage series resistor is? of course a really good way to measure idling (or any) plate current.? And the best way to set the bias voltage.
But be VERY CAREFUL.? When you're using a multi-meter, it may be obvious,? but REMEMBER that BOTH leads are at plate voltage potential....? be mindful of what those leads touch and where you place the meter.
--
73/Rick
W4XA
__________________________________
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Good Stuff, thanks very much! wa3gin
That is the test point used to set the bias (PA idle current). See section 4-10 of the factory manual.
For a helpful mod for adjusting idle current see:?
Walt Cates, WD0GOF
?
A majority of acceptance is not proof of correctness.
My 32A has a test point located near the 6AB4 tube in the front of the chassis.? What does it test?
Thanks-George KN3PAT
|
That is the test point used to set the bias (PA idle current). See section 4-10 of the factory manual.
For a helpful mod for adjusting idle current see:?
Walt Cates, WD0GOF
?
A majority of acceptance is not proof of correctness.
toggle quoted message
Show quoted text
My 32A has a test point located near the 6AB4 tube in the front of the chassis.? What does it test?
Thanks-George KN3PAT
|
My 101 drifts, and from what I read is a common problem.? I see several possible cures for it. 1) VFO because it has a drift correction adjustment that is simple to manipulate. This from a post on 2/2015.? I can't find any info on this adjustment?? Where is that adjustment located and how do you do it?
2)Re-cap it.? I dread the thought of working on this beast.? But does anyone recommend a good re-cap kit?
3)Replace the 6c4 with a 7 pin pentode?? Any recommendations on the pentode.? Is this an easy "drop in" replacement?
I use this receiver along with my HT-32A.? A lot of enjoyment, even with the drift!
Thanks for the help!
George-KN3PAT
|
My 32A has a test point located near the 6AB4 tube in the front of the chassis.? What does it test?
Thanks-George KN3PAT
|
Re: My HT-45 HP-45 project.
It's looking pretty good!? 2800V should easily get you about 600W or more? if it doesn't drop too much under load!
Running 3KV through an octal plug is very scary though!? You might want to consider using the HV connector for that purpose.
85mA seems a little high.? Someone might have changed that resistor across the terminal in the back.
With the terminal open, I think it should be somewhere around 50ma.....that coupled with the current due to the 210K bleeder is supposed to be enough to "swing" the choke.
Mine with 2600V did about 600W output with 45-50w drive.
--
73/Rick
W4XA
__________________________________
All posts are created using OpenSuSE Leap 15.5 x64 Linux
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Re: My HT-45 HP-45 project.
Hi Bob,
You've got it well down the road at this point.? It really looks like a nice example from what, 60 yrs ago or so?? Can't be too many that are in better shape than that.
While the Jones connector wouldn't seem a natural first choice for HV+ , I suspect the guys in the lab did a lot of HiPot testing before they let that be the connector of choice .? As long as there's no other conductors in that plug it's feasible (especially since it seems to work!) but the metal shell becoming grounded somehow might be a concern.
It would be neat to know what that actual (core?) temp drop those fins on the transformer housing deliver.? Given the "10 deg C drop doubles the life of the electrical component" axiom, it seems like a great idea (and one that could be used in other designs).
I can't remember which transmitter I was working on years ago (32V2?) when I noticed that the power trans (black) was about a half inch away from a large envelope tube with a toasty filament in the chassis. I put a thin piece of aluminum between the (black) transformer housing and the tube, as tubes are << expensive than power transformers? and every bit helps.
Thanks for sharing the pictures of the project.
You're almost done!
John K5MO
Hi John.
That's the factory supply and original transformer. It came with fins! You can see them in the manual photos.
Somewhere along the line, the 866As were replaced by a pair of solid state rectifiers.
I fired it up today. Initially ran 120V to 240V wired HV transformer. No smoke or bang. Swapped wires and still no smoke or bang.
With grid grounded, there's a pleasant glow from the anode.? Meter reads ~2800 V and ~85 mA. Misplaced my HV probe so
verification will have to wait a bit until it's found.?
Will apply drive later today or Saturday. Have to clear space on the bench first :-)
You can just make out some red glow from the anode.?
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Re: My HT-45 HP-45 project.
Hi John.
That's the factory supply and original transformer. It came with fins! You can see them in the manual photos.
Somewhere along the line, the 866As were replaced by a pair of solid state rectifiers.
I fired it up today. Initially ran 120V to 240V wired HV transformer. No smoke or bang. Swapped wires and still no smoke or bang.
With grid grounded, there's a pleasant glow from the anode.? Meter reads ~2800 V and ~85 mA. Misplaced my HV probe so
verification will have to wait a bit until it's found.?
Will apply drive later today or Saturday. Have to clear space on the bench first :-)
You can just make out some red glow from the anode.?
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Re: My HT-45 HP-45 project.
Looks great. Did you add the heat sinks to the transformer? It's a nice job.
Nice looking amp! John
I mentioned this in Rick's thread about his new power supply. /g/HallicraftersRadios/topic/ht45_loudenboomer_working_now/106322290
So far I've:
Replaced a resistor in and verified PS operation, with ~24 V on the transformer primary and 110k load, makes ~750 V. This translated to 3750 V with 120 V input.When connected to the amp and with the tube drawing 120 mA per design, modeling, with the Duncan Amps PUS Designer II, shows the specified ~3000 V.
Replaced the open Ig and Ip metering resistors.
Added a protection diode for the meter.
Hopeful for today.
Get it dusted out. Gotta buy a new dust brush. Grandkids made off with mine.
Temporarily wire RF deck AC separately to run heater and blower.??
Run HV off a variac with the tube biased to conduct at low voltage and run the anode red-orange for a while.
In time, I'll hook the nano VNA up and see how input and output look over 3.5-30 MHz range. It will be nice to learn if the amp is OK for any of the WARC bands.?
Photos: I have all the covers, screws, etc.
Note the Jones plug on the RF deck power cable. 3 kV @ 330 mA goes through this connector. Pins are on the cold end.
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I mentioned this in Rick's thread about his new power supply. /g/HallicraftersRadios/topic/ht45_loudenboomer_working_now/106322290So far I've: Replaced a resistor in and verified PS operation, with ~24 V on the transformer primary and 110k load, makes ~750 V. This translated to 3750 V with 120 V input.When connected to the amp and with the tube drawing 120 mA per design, modeling, with the Duncan Amps PUS Designer II, shows the specified ~3000 V. Replaced the open Ig and Ip metering resistors. Added a protection diode for the meter. Hopeful for today. Get it dusted out. Gotta buy a new dust brush. Grandkids made off with mine. Temporarily wire RF deck AC separately to run heater and blower.?? Run HV off a variac with the tube biased to conduct at low voltage and run the anode red-orange for a while. In time, I'll hook the nano VNA up and see how input and output look over 3.5-30 MHz range. It will be nice to learn if the amp is OK for any of the WARC bands.? Photos: I have all the covers, screws, etc. Note the Jones plug on the RF deck power cable. 3 kV @ 330 mA goes through this connector. Pins are on the cold end.
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Re: New P2000 Rear panels
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HI,
I think this is the 2nd time I've emailed you on subject. Still waiting to hear the cost. I can't commit without knowing the total cost including delivery.
Thanks for doing this,
dave
wa3gin
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Re: New P2000 Rear panels
HI,
I think this is the 2nd time I've emailed you on subject. Still waiting to hear the cost. I can't commit without knowing the total cost including delivery.
Thanks for doing this,
dave
wa3gin
|
Re: New P2000 Rear panels
Please email me if you want a panel. They are done and ready to ship.? Clark at Clark Turner Tuning? Or use QRZ
C
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Re: Replacing the speaker in a S-20 R
Richard,
Thanks?for the information, just what I needed to know.
John WD5ENU
On Tue, Jun 25, 2024 at 11:40 Richard Knoppow via <1oldlens1= [email protected]> wrote: The speaker field can be replaced with a 1500 ohm, 10 Watt wire
wound resistor. See the schematic for the S-40 or S-40A for details. I
am not sure what the plate load for the transformer should be but about
5K ohms is typical for single pentode power amps. Speaker side is
whatever matches the speaker you are using.
Your transformer sounds more like a line matching transformer than
an output transformer. Is the original transformer gone? Typically a
single pentode wants a plate load on the order of 5K. The DC resistance
of the speaker voice coil will be close to its impedance for replacement
type speakers, usually somewhere around 3 to 8 ohms, not very critical.
I wonder about the power rating, does it say that on the speaker? Sounds
to high to me. If this is a modern woofer or full range speaker it may
not be efficient enough for the low power amplifier in the receiver. The
single pentode amps will put out on the order of one watt or two watts
maximum with a lot of distortion. See a tube handbook or data sheet for
some idea of the impedance and power output. One watt into the kind of
speaker originally used in these receivers will make quite a loud sound.
However, the small, full range speakers used for quite some time now,
trade efficiency for low frequency response and may need a lot of power.
FWIW, in old tube receivers a typical single tube audio amp will
put out a maximum of maybe 2 watts while a push-pull amp will put out
anywhere from 10 to 20 watts. Distortion in either case will be
substantially greater than the sort of specs one sees on modern hi-fi amps.
The original speaker was mounted on soft rubber gromets to isolate
it mechanically. This is to prevent mechanical feedback to the
microphonic tuning capaictor which will cause howling at quite modest
volume levels.
Try your speaker. if it works that's fine but be aware of potential
problems.
On 6/25/2024 8:01 AM, John Watkins wrote:
I know I have asked about this before, but lost the return email.? I
have an 8 Ohm 5 inch 20 watt speaker and an audio transformer, primary
is 500, 1500, 2000, and 3000 Ohms.? Secondary is 4,8,and 16 Ohms.? What
should I replace the speaker field coil with, or just leave it as is?
Thanks,
John WD5ENU
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998
|
Re: Replacing the speaker in a S-20 R
The speaker field can be replaced with a 1500 ohm, 10 Watt wire
wound resistor. See the schematic for the S-40 or S-40A for details. I
am not sure what the plate load for the transformer should be but about
5K ohms is typical for single pentode power amps. Speaker side is
whatever matches the speaker you are using.
Your transformer sounds more like a line matching transformer than
an output transformer. Is the original transformer gone? Typically a
single pentode wants a plate load on the order of 5K. The DC resistance
of the speaker voice coil will be close to its impedance for replacement
type speakers, usually somewhere around 3 to 8 ohms, not very critical.
I wonder about the power rating, does it say that on the speaker? Sounds
to high to me. If this is a modern woofer or full range speaker it may
not be efficient enough for the low power amplifier in the receiver. The
single pentode amps will put out on the order of one watt or two watts
maximum with a lot of distortion. See a tube handbook or data sheet for
some idea of the impedance and power output. One watt into the kind of
speaker originally used in these receivers will make quite a loud sound.
However, the small, full range speakers used for quite some time now,
trade efficiency for low frequency response and may need a lot of power.
FWIW, in old tube receivers a typical single tube audio amp will
put out a maximum of maybe 2 watts while a push-pull amp will put out
anywhere from 10 to 20 watts. Distortion in either case will be
substantially greater than the sort of specs one sees on modern hi-fi amps.
The original speaker was mounted on soft rubber gromets to isolate
it mechanically. This is to prevent mechanical feedback to the
microphonic tuning capaictor which will cause howling at quite modest
volume levels.
Try your speaker. if it works that's fine but be aware of potential
problems.
toggle quoted message
Show quoted text
On 6/25/2024 8:01 AM, John Watkins wrote: I know I have asked about this before, but lost the return email.? I
have an 8 Ohm 5 inch 20 watt speaker and an audio transformer, primary
is 500, 1500, 2000, and 3000 Ohms.? Secondary is 4,8,and 16 Ohms.? What
should I replace the speaker field coil with, or just leave it as is?
Thanks,
John WD5ENU
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998
|
Floyd - K8AC
waltcates
Anthony W. DePrato
Rick W7IMM
Dave Jordan
Bob ah7i