Well, just because the tubes are new...
Possibly just an alignment problem... some golden screwdriver been in there?
Have you jiggled the VFO/XTAL switch on the side?? You are tuning the cal signal so the oscillators are probably
working, but not strong enough at the mixer.. I am thinking.
73,
Gary
WB6OGD
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I assume the hum. Is present when volume is all the way down¡
That would leave three things, the output tube as mentioned, heater to cathode short (60 Hz hum), the filter capacitor (120 Hz hum), as mentioned, and finally the grid blocking capacitor (60 Hz hum).
Gary
W0DVN
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On Mar 29, 2021, at 8:56 PM, Richard Knoppow <1oldlens1@...> wrote:
They don't have to touch. You can get hum from tubes with leaky cathode to heater insulation. This is a fairly common problem in audio. You have to swap the tubes to find out.
On 3/28/2021 11:05 AM, Steve Wedge, W1ES/4 via groups.io wrote:
This could also be a bad tube in that chain. I've heard of filaments touching the cathode that can cause this.
Steve Wedge, W1ES/4
Time flies like an arrow. Fruit flies like a banana.
Sent with ProtonMail <> Secure Email.
©\©\©\©\©\©\©\ Original Message ©\©\©\©\©\©\©\
On Sunday, March 28, 2021 12:28 PM, Cowan Bowman <cowan@...> wrote:
Hello all.
The rig has an audio hum that is heard on the speaker when switching to any band except 80 and 20 meters. When 80 or 20 is selected the hum is not present. I still can hear transmissions by others, but the hum is fairly loud and makes it difficult.
According to the previous owner, the radio had not been powered up in over 25 years. So far I have cleaned out all the dust, replaced a couple bad resistors (R163 and R192). Tested all of the tubes and they are all good.
Any words of advice on what I should do to troubleshoot what it could be?
Thanks,
Cowan
N5QDH --
Richard Knoppow
1oldlens1@...
WB6KBL
|
They don't have to touch. You can get hum from tubes with leaky cathode to heater insulation. This is a fairly common problem in audio. You have to swap the tubes to find out.
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Show quoted text
On 3/28/2021 11:05 AM, Steve Wedge, W1ES/4 via groups.io wrote: This could also be a bad tube in that chain.? I've heard of filaments touching the cathode that can cause this.
Steve Wedge, W1ES/4
Time flies like an arrow.? Fruit flies like a banana.
Sent with ProtonMail <> Secure Email.
©\©\©\©\©\©\©\ Original Message ©\©\©\©\©\©\©\
On Sunday, March 28, 2021 12:28 PM, Cowan Bowman <cowan@...> wrote:
Hello all.
The rig has an audio hum that is heard on the speaker when switching to any band except 80 and 20 meters.? When 80 or 20 is selected the hum is not present.? I still can hear transmissions by others, but the hum is fairly loud and makes it difficult.
According to the previous owner, the radio had not been powered up in over 25 years. So far I have cleaned out all the dust, replaced a couple bad resistors (R163 and R192).? Tested all of the tubes and they are all good.
Any words of advice on what I should do to troubleshoot what it could be?
Thanks,
Cowan
N5QDH
--
Richard Knoppow
1oldlens1@...
WB6KBL
|
Trying to bring an R4b back to life.? I'm not home, test equipment limited to a fluke 787 and a AA-230 that serves as a signal generator.? Can cap sections replaced and all switches and pots cleaned.? Tubes were tested before I left home and duds were replaced.? Here is where I ran into problems- setting up to do voltage checks there is no noticeable preselect noise peak, at least not where you would expect it. Using the R4B calibrator I have very weak signal peak in correct preselect window for each band and confirmed with the AA-230 that the PTO ect is ok as I can tune through a generated signal with the PTO.? V2 pin 7 shows 2.8v in the manual at the cathode - I measure 0v, cathode resistor is in spec. V2 pin 6 measures 44 volts where as the manual calls out 80v.? All other tube voltage checks are correct.? Both 6HS6's and the 6BZ6 are new tubes.? With what I have to work with where to next?? any thoughts appreciated -Ron K0IDX
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Re: DR7 fitting partial success.
Hi Jim
I dont know if they are available in the UK but I will check them out.
?
Kind Regards
Mike G3ZCC
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On Mon, Mar 29, 2021 at 01:40 PM, Joe Wolfe wrote:
To all¡again¡
?
Please, cut and paste, or reply, to the message or part of a message, to which you are replying.? Many people delete messages as they read them, as they read the posts via their phones or tablets, and as such, have nothing with which to refer.
?
I have asked before, as this is just good netiquette.? It is not hard to do, and not time consuming¡ALL message readers allow one to do this, even the phone allow it.
?
Thank you!
?
Joe Wolfe ¨C W7RKN
Co-Moderator/Co-Owner
Thanks for the heads up, Joe.? In my case, my original log-in was lost or got corrupted, and this is the first time I'm getting a notification.? I very much enjoy reading everyone's comments and I learn much from this group.? I've been a Drake fan for over 55 years now.? Wish they would reenter the market. Best 73s to all, Harv WB6TTF
?
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To all¡again¡ ? Please, cut and paste, or reply, to the message or part of a message, to which you are replying.? Many people delete messages as they read them, as they read the posts via their phones or tablets, and as such, have nothing with which to refer. ? I have asked before, as this is just good netiquette.? It is not hard to do, and not time consuming¡ALL message readers allow one to do this, even the phone allow it. ? Thank you! ? Joe Wolfe ¨C W7RKN Co-Moderator/Co-Owner ? ? Wish I could have read the message you are replying too, not a health issue??
|
I'd like to see the original post too, please Thanks Denis, N5KX
Wish I could have read the message you are replying too, not a health issue??
Tim
WB8UHZ
On Monday, March 29, 2021, 9:13:43 AM EDT, gary schnakenberg < wb2jax@...> wrote:
Well said..this plandemic is proof it is not a health issue it is an economic issue..
--
Denis, N5KX
|
Wish I could have read the message you are replying too, not a health issue??
Tim
WB8UHZ
On Monday, March 29, 2021, 9:13:43 AM EDT, gary schnakenberg <wb2jax@...> wrote:
Well said..this plandemic is proof it is not a health issue it is an economic issue..
|
I've finally gotten up the time/courage to get back into my TR7; have
fixed several bad counters on the DR-7 board, and figured out that
clearances for the replacement German made display board are so tight
that I have to pull off the dial lamp socket that clips on under it.
I recall that there was talk of Drake adding fish paper somewhere, but
danged if I can find the article.
I've found one benefit to my advancing years: I'm MUCH more cautious
with things that don't seem right, spending time with flashlight and
magnifier to figure out what's REALLY going on with things that once
fit fine and now don't!
TIA.
--
Gary Woods O- K2AHC Public keys at home.earthlink.net/~garygarlic,
or get 0x1D64A93D via keyserver
fingerprint = E2 6F 50 93 7B C7 F3 CA 1F 8B 3C C0 B0 28 68
--
Gary Woods O- K2AHC Public keys at home.earthlink.net/~garygarlic, or get 0x1D64A93D via keyserver
fingerprint = E2 6F 50 93 7B C7 F3 CA 1F 8B 3C C0 B0 28 68
--
This email has been checked for viruses by Avast antivirus software.
|
Well said..this plandemic is proof it is not a health issue it is an economic issue..
|
Re: Drake Transmitting Convertors
Rick - I wanted to chime in - I've had TC2/TC6/SC2/SC6 set up in the past with R4/T4X series (still have the equipment, just no space in operating position to set it all up currently), and one minor inconvenience I found was that CW mode is in lower sideband offset, which means (meant in my case) that switching from SSB to CW was more than just changing the mode switch(es). Also, the final tube in the TC2 is type 8643 (a dual tetrode something like a 5894 but a bit larger) which isn't very common (although I ran into some used tubes of the same type bearing a Motorola part number years ago.) Never tried the units with TR4 so don't know if the (LSB-arranged) CW offset behaves the same; could be a little more complicated if no RIT. By the same token, could probably transmit CW by putting a clean sine wave into the mic jack (using the kind of connections used for digital modes nowadays) and transmitting in USB mode.
Good luck getting your station set up!
Dave
|
Re: DR7 fitting partial success.
I have a Clearspeech Base that is a magic box and I also run a JPS NIR-12. Have used a Timewave DSP-9 with good results but the JPS and Clearspeech rock. 73 -Jim NU0C On Sun, 28 Mar 2021 18:32:33 -0700 "Mike Davidsohn G3ZCC" <mike@...> wrote: However an external DSP unit in line with an external speaker on the TR7 will cure that.
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Re: DR7 fitting partial success.
Hi Steve
I did the same, went over the alignment again because of all the pulling about.
It hadn't shifted a jot.
Good luck with yours and keep us posted how you get on.
Kind Regards
Mike
G3ZCC??
|
Re: DR7 fitting partial success.
Hi Peter
Thank you for your kind words and yes hopefully my exploits will help someone else.
I have been using the TR7 side by side with my Yaesu FTDX 3000 during the contest this weekend the Drake has the edge in sensitivity but the Yaesu has the edge with selectivity, but only just.
It beats the TR7 on QRN reduction with its DNR which is quite spectacular..
However an external DSP unit in line with an external speaker on the TR7 will cure that.
The thing was that the TR7 held it's own under very busy conditions.
?
Kind Regards
Mike
G3ZCC??
|
Re: DR7 fitting partial success.
Hi Roger
I have the transmitter of the pair, an early "duck egg" 2000, 2000 G Line, 2000A,B, E. and a KW Atlanta
Plus a KW 600 and KW 1000 Linear.
All working, if you need any schematics or help with yours, message me.
Kind Regards
Mike?
G3ZCC
|
Re: Need Crystal freq. for 28.5 mhz in TR4C
Thanks for the reply.? Once I finish getting here working I will contact you regarding some crysta;s
Greg
|
Re: Wanted - Drake TR-4C S-meter
Thanks Steve, That's good to know.
73, Doug
On Sunday, March 28, 2021, 6:47:58 AM CDT, Steve Wedge, W1ES/4 via groups.io <w1es@...> wrote:
Doug, all the TR-3/TR-4 meters are interchangeable.?
Be aware that some of them have a problem with damping (frequently called ¡°bouncy¡± or ¡°bouncing¡±). Ask before you buy.?
73,
Steve Wedge, W1ES/4
Time flies like an arrow.? Fruit flies like a banana.
Sent from ProtonMail for iOS
On Sun, Mar 28, 2021 at 00:17, Doug < ke4vbg@...> wrote: Hello
I am looking for an S-meter that will work in my TR-4C. I'm not sure if a TR-4 or TR-3 are compatible. Service Manual does not list these in the Parts List and can't find what the Range is. Any help is appreciated.
Doug KE4VBG
|
That's odd, I had no clearance problems at all with the German board. 73 -Jim NU0C On Sun, 28 Mar 2021 16:54:09 -0400 "Gary Woods" <garygarlic@...> wrote: I've finally gotten up the time/courage to get back into my TR7; have
fixed several bad counters on the DR-7 board, and figured out that
clearances for the replacement German made display board are so tight
that I have to pull off the dial lamp socket that clips on under it.
I recall that there was talk of Drake adding fish paper somewhere, but
danged if I can find the article.
I've found one benefit to my advancing years: I'm MUCH more cautious
with things that don't seem right, spending time with flashlight and
magnifier to figure out what's REALLY going on with things that once
fit fine and now don't!
TIA.
--
Gary Woods O- K2AHC Public keys at home.earthlink.net/~garygarlic, or get 0x1D64A93D via keyserver
fingerprint = E2 6F 50 93 7B C7 F3 CA 1F 8B 3C C0 B0 28 68
--
This email has been checked for viruses by Avast antivirus software.
|
The fish paper goes across the top of the PTO lamp metal and prevents the DR7 display solder pads from touching that grounded surface.
Gary
W0DVN
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On Mar 28, 2021, at 3:54 PM, Gary Woods <garygarlic@...> wrote:
I've finally gotten up the time/courage to get back into my TR7; have
fixed several bad counters on the DR-7 board, and figured out that
clearances for the replacement German made display board are so tight
that I have to pull off the dial lamp socket that clips on under it.
I recall that there was talk of Drake adding fish paper somewhere, but
danged if I can find the article.
I've found one benefit to my advancing years: I'm MUCH more cautious
with things that don't seem right, spending time with flashlight and
magnifier to figure out what's REALLY going on with things that once
fit fine and now don't!
TIA.
--
Gary Woods O- K2AHC Public keys at home.earthlink.net/~garygarlic, or get 0x1D64A93D via keyserver
fingerprint = E2 6F 50 93 7B C7 F3 CA 1F 8B 3C C0 B0 28 68
--
This email has been checked for viruses by Avast antivirus software.
|
Gary WB6OGD
Mike Davidsohn G3ZCC
wb6ttf
gary schnakenberg
Jim Shorney
Doug