Why do they sometimes use two caps in parallel on some amps? But others only have one?
|
I¡¯m probably going to get this back together today if time permits. Getting more rigs in to repair for others so I have to get moving :-)
Steve Wedge, W1ES
Time flies like an arrow. Fruit flies like a banana.
On Wed, Feb 5, 2025 at 21:05, KB9VY via groups.io < lcoblentz3@...> wrote:
You¡¯re most welcome Steve! ?73, de KB9VY.
On Wed, Feb 5, 2025 at 20:55, Steve Wedge, W1ES/4 via groups.io <
w1es@...> wrote:
Thanks to Lawrence Coblenz.?
I have confirmed that the transformer is original but the capacitors are not. The transformer was glued to the top of the weight bar in the bottom of the base.?
I¡¯ll be starting my testing with the caps removed. The element reproduces my whistling and voice as seen on an oscilloscope.?
73,
Steve Wedge, W1ES
Time flies like an arrow. Fruit flies like a banana.
|
Re: Warning on the 7077 (and any plastic Astatic mic)
Thanks, Jim. Sometimes, I miss things.?
Steve Wedge, W1ES
Time flies like an arrow. Fruit flies like a banana.
On Wed, Feb 5, 2025 at 21:02, Jim Shorney via groups.io < jimNU0C@...> wrote:
Again, the origial cartridge is a cheap low impedance dynamic.
On Wed, 05 Feb 2025 21:53:57 +0000
"Steve Wedge, W1ES/4 via groups.io" <w1es@...> wrote:
> I still don¡¯t know why anyone would have installed a low-Z element unless the original high-Z one had died and the low-Z element was what they had available.
--
73
-Jim
NU0C
|
Re: Drake TR7, TX issue any ideas?
Agree Jim, have ordered batch of 6 so both will be replaced!
But I actually think you nailed it, situation improved with the PIN out of the circuit! Power consumption on 15Meters now dropped to ~24 amps from 31 Amps so great improvement! Also power output on 10Meters increased to ~30Watts from ~5Watts range, so I feel that good times are ahead :). New pin diodes and an Predrive / ALC alignment will probably improve the output. But let's see when the mailman drops by.
Again, Thanks for your time Jim, appreciate it!
?73's Michael.
I would replace both in the pair just to be safe. However you can see the results just by removing the bad diode from the circuit. It is only needed for the calibrator signal.
On Thu, 6 Feb 2025 08:17:36 +0100
"Michael Jensen via " <kavigal=[email protected]> wrote:
> Great Thanks! Jim, looking forward to replace the diode and see the result.
> I'll be back ;).
>
> 73's De Michael.
>
> On Thu, Feb 6, 2025 at 2:59?AM Jim Shorney via <jimNU0C=
> [email protected]> wrote:?
>
> >
> > Not quite. It is connected to the common signal path and will cause
> > problems if it has failed.
> >
> > On Wed, 5 Feb 2025 18:29:00 +0100
> > "Michael Jensen via " <kavigal=[email protected]> wrote:
> >?
> > > however I
> > > assume CR1402 has little to do with TX and only RX/Calibrator signal??
--
73
-Jim
NU0C
|
Re: Drake TR7, TX issue any ideas?
I would replace both in the pair just to be safe. However you can see the results just by removing the bad diode from the circuit. It is only needed for the calibrator signal. On Thu, 6 Feb 2025 08:17:36 +0100 "Michael Jensen via groups.io" <kavigal@...> wrote: Great Thanks! Jim, looking forward to replace the diode and see the result.
I'll be back ;).
73's De Michael.
On Thu, Feb 6, 2025 at 2:59?AM Jim Shorney via groups.io <jimNU0C=
[email protected]> wrote:
Not quite. It is connected to the common signal path and will cause
problems if it has failed.
On Wed, 5 Feb 2025 18:29:00 +0100
"Michael Jensen via groups.io" <kavigal@...> wrote:
however I
assume CR1402 has little to do with TX and only RX/Calibrator signal?
-- 73 -Jim NU0C
|
Re: Mini collection of DRAKE by SP3SWJ
I just wanted to show off my mini collection? of DRAKE radio.
35 years ago I fell in love with these radios .
15 years ago I started collecting them ;-)
?Well, this is the current effect:
One radio is fully working the others are waiting to be looked at, checked, started up. I jave some spare tubes and I have a meter to measure the tubes. Work in progress.
Jerry
SP3SWJ
|
Mini collection of DRAKE by SP3SWJ
I just wanted to show off my mini collection? of DRAKE radio.
35 years ago I fell in love with these radios .
15 years ago I started collecting them ;-)
?Well, this is the current effect:
One radio is fully working the others are waiting to be looked at, checked, started up. I jave some spare tubes and I have a meter to measure the tubes. Work in progress.
Jerry
SP3SWJ
|
Re: Drake TR7, TX issue any ideas?
Great Thanks! Jim, looking forward to replace the diode and see the result. I'll be back ;).
73's De Michael.
Not quite. It is connected to the common signal path and will cause problems if it has failed.
On Wed, 5 Feb 2025 18:29:00 +0100
"Michael Jensen via " <kavigal=[email protected]> wrote:
> however I
> assume CR1402 has little to do with TX and only RX/Calibrator signal?
--
73
-Jim
NU0C
|
As shown by my photos. On Thu, 06 Feb 2025 01:55:56 +0000 "Steve Wedge, W1ES/4 via groups.io" <w1es@...> wrote: I have confirmed that the transformer is original but the capacitors are not -- 73 -Jim NU0C
|
You¡¯re most welcome Steve! ?73, de KB9VY.
On Wed, Feb 5, 2025 at 20:55, Steve Wedge, W1ES/4 via groups.io < w1es@...> wrote:
Thanks to Lawrence Coblenz.?
I have confirmed that the transformer is original but the capacitors are not. The transformer was glued to the top of the weight bar in the bottom of the base.?
I¡¯ll be starting my testing with the caps removed. The element reproduces my whistling and voice as seen on an oscilloscope.?
73,
Steve Wedge, W1ES
Time flies like an arrow. Fruit flies like a banana.
|
Re: Warning on the 7077 (and any plastic Astatic mic)
Again, the origial cartridge is a cheap low impedance dynamic. On Wed, 05 Feb 2025 21:53:57 +0000 "Steve Wedge, W1ES/4 via groups.io" <w1es@...> wrote: I still don¡¯t know why anyone would have installed a low-Z element unless the original high-Z one had died and the low-Z element was what they had available. -- 73 -Jim NU0C
|
Re: Drake TR7, TX issue any ideas?
Not quite. It is connected to the common signal path and will cause problems if it has failed. On Wed, 5 Feb 2025 18:29:00 +0100 "Michael Jensen via groups.io" <kavigal@...> wrote: however I
assume CR1402 has little to do with TX and only RX/Calibrator signal? -- 73 -Jim NU0C
|
Thanks to Lawrence Coblenz.?
I have confirmed that the transformer is original but the capacitors are not. The transformer was glued to the top of the weight bar in the bottom of the base.?
I¡¯ll be starting my testing with the caps removed. The element reproduces my whistling and voice as seen on an oscilloscope.?
73,
Steve Wedge, W1ES
Time flies like an arrow. Fruit flies like a banana.
|
I am in need of a VSWR set knob for the MN4C.
Anyone have one laying around or can tell me where to find one?
?
See picture attached.
I'm good on QRZ.
?
Thanks,
Ron WB4OQL
Clyde, NC
|
Re: TR4310 HF Transceiver
On 2025-02-05 14:18, Gary WB6OGD via groups.io wrote: Yesss..
Jerry,
I talked to you abut a Teensy speech processor after hearing about
your excellent work on your KWM-2 CW mod.
I just ordered a Teensy 4.0! *** Excellent. Use the graphic audio design tool at PJRC.com. For the KWM-2 project, I didn't use any sort of audio card. I used an ADC ( analog input ) pin for input, and a sort of PWM output they support called "MQS". MQS sounds amazingly good. - Jerry
|
Re: TR4310 HF Transceiver
I would very much like a software phasing ssb generator.
On Wed, Feb 5, 2025 at 5:18?PM Gary WB6OGD via <winbladgary= [email protected]> wrote: Yesss..
?
Jerry,
I talked to you abut a Teensy speech processor after hearing about your excellent work on your KWM-2 CW mod.
I just ordered a Teensy 4.0!
?
This should be a fun new project after years of Arduino fun,? though I will be starting out from the bottom..? hi hi.
73,
Gary
WB6OGD
?
-- Frank Barnes
Chapel Hill, NC
Grid Square FM05
Cell 919.260.7955
|
Re: TR4310 HF Transceiver
Yesss..
?
Jerry,
I talked to you abut a Teensy speech processor after hearing about your excellent work on your KWM-2 CW mod.
I just ordered a Teensy 4.0!
?
This should be a fun new project after years of Arduino fun,? though I will be starting out from the bottom..? hi hi.
73,
Gary
WB6OGD
?
|
Re: Warning on the 7077 (and any plastic Astatic mic)
For clarification, I believe that the head was glued to the base at the factory and the screw held it in place.?
If any of you have a 7077 that¡¯s partially disassembled, please let me know if this is what you see.?
I still don¡¯t know why anyone would have installed a low-Z element unless the original high-Z one had died and the low-Z element was what they had available. There could have been some ¡°mod¡± passed around to improve the performance. I know that this mic, stock, isn¡¯t held in high regard¡
Steve Wedge, W1ES
Time flies like an arrow. Fruit flies like a banana.
On Wed, Feb 5, 2025 at 14:36, Steve Wedge, W1ES/4 via groups.io < w1es@...> wrote:
As I grind my way through figuring what is wrong with this mic and how to repair it, I came upon an "O Cr@p!" moment when trying to disassemble it.
You see, the wiring that came up through the vertical bit to the head had fallen down and was flopping around loose, with the base.? Looking at? the inside of the head, I saw a phillips screw and throught, "Great!, I will remove the head from the stand and then I can feed the wiring up through the stand, then through the head."? and so on.
Dueing manufacture, the head is assembled to the base and held in place by that screw.? AND with glue!? The result is, if you're expecting the head to come off the base after removing the screw, it will but not in the way that you'd expect.? It broke.
Upon looking at the break, I could see evidence of glue that was the undoing of this mic.? Seeing that there was glue, I wondered if i could just do some "airplane glue" type joinery (IOW, was the glue similar to PVC pipe cement?).? It appears that I was correct and the head is back on the base but I'm going to be careful with it now.
If you lose the wiring through the base, the best way to get it back will be to fish some string down through the head and base and pull it back up that way.
It's a minor thing but may be useful to someone in the future.
I'm still troubleshooting the mic itself.? From what I'm seeing, the element in my mic is low-Z (hence the 400 ohm resistance across its terminals0..? Looking on my scope at 20 mV/div, I get a less than 20mV signal when I whistle into the element by itself (not connected to the mic).? I get signals of 50 - 100mV out at the white wire but before the connector.? Someone put a different element in there sometime before 2019, when I bought the TR7 that came with this mic.
The connection of the circuit is series cap --- primary || secondary -- series cap.? Transformer is 3 wires, so the cold sides of the windings are common-connected.
I'll be redoing all the connections and reassembling the 7077 with better workmanship.? I may not be able to avoid electrical tape but I'll at least know that the solder connections are good.
73,
Steve Wedge, W1ES
Time flies like an arrow.? Fruit flies like a banana.
Sent with
secure email.
|
Plate blocking cap? It's a TDK 1700pf 20kv.
|
Plate blocking cap? It's a TDK 1700pf 20kv.
|
Jim Shorney
Gary WB6OGD
