Re: New to me drake 4 twins
The guy offering 100 is a moron and trying to take advantage of you!? Power supply alone goes for more than that.?
New to the group and?I just came into an old Drake 4B set. This radio set is super cool, turns on, transmits (although I don¡¯t know where) and the amp is pristine and quite easily put out 1kw when I drove it with a different radio. I¡¯d love to keep it and make it work again, but it¡¯s so far before my time that I really don¡¯t know what I¡¯m looking at, if you want to know the truth. Originally licensed in 1993 and this gear was old then!? This is my first tube type anything to try and use.
I have the power supply for the radio set and the power supply for the amp and I¡¯d like to keep this set together. I¡¯ve had several people ask me how much I want for it but I think I want to keep it. Besides, eBay is the only place I¡¯ve looked to find a value and I don¡¯t know what category this set would fall into, working, parts only, etc. One guy offered me $100 for the radio set and power supply, but I¡¯ll box it up and put it in the attic for that much!? It¡¯s just so cool. I was surprised by the color of the meter backlights too, what a treat!? The amp looks super cool as well!
Problem I have is it really won¡¯t fit into how I currently operate, so I¡¯m still on the fence about keeping it or passing it on. ?I¡¯ve been learning all I can but I know when my knowledge limit has been reached. I¡¯m considering keeping it as a full on restoration project, though it already looks super clean on the outside and the inside. I did an internet search for drake restoration and found a few websites dedicated to it. So it occurred to me that I might be inclined to send it off for rework if it needs it.?
So far, I am unable to get any speaker audio, not even a crackle. I tested the speaker with a 9v battery and it made noise. I ohmed out the cord at 3.5ohm. So I suspect maybe the socket on the receiver is bad. I don¡¯t know. I can make it transmit, it puts out about 125w into a dummy load when I peak it with a calibrated ARRL whistle, but I really don¡¯t know what I¡¯m doing and don¡¯t hear anything on my shack radio on the freq I think I¡¯m transmitting on. It¡¯s very likely operator error, but I¡¯d like any opinions or advice someone can offer me.?
There¡¯s also this little circuit board that was plugged into the back accessory port thats a drake 4-LF, but I can¡¯t find any info on it. I actually have the leaflet for it from Drake, but it¡¯s beyond my knowledge. To be honest, I haven¡¯t the slightest idea what it¡¯s supposed to do or if it was an option or aftermarket or anything. There just doesn¡¯t seem to be much info on the web about it, so hopefully someone on here can shed some light on this thing.??
I¡¯ll be happy to post pictures or send them to someone individually if it at all helps. I¡¯m not much for being on message boards, or any social media to be honest, and it¡¯s unlikely I¡¯d be able to offer anyone here any value unless you need me to climb your tower!
So thanks in advance for your time and anything someone can offer me.
warmest regards and 73
Ryan Jones
Beaumont TX?
NV5E
|
Re: New to me drake 4 twins
Thanks for the swift feedback guys! I¡¯m on duty at the fire station today, so I have limited time to check on the thread here. I¡¯ll follow up later on. Y¡¯all are giving me some great info already!
Ryan
NV5E
|
Re: New to me drake 4 twins
Congrat's on getting yourself a gem of a radio!
But first things first -- tell the jackass that offered you $100
to take a sweet flying f***.
As a very rough ball park, an AC-3/4 power supply sells for around
$140. A working set of twins commands about $250-300 each for the
tx and tx. Again, those are very rough estimates. (And sometimes
there are deals. Last month I bought a complete B-line with
MS-4 and AC-4 for CAD$500! That's about $355 in real money :-))
But don't even think about selling them. Even if you have no
experience with tube radios, it doesn't take long to learn the
basics. Remember, novice class license holders built their own
tubes rigs for decades.
If you can, get your hands on a mid-60s ARRL handbook and start
reading. If you know transistor circuit theory, you're already
well on your way. There are lots of great texts and articles about
tube circuits and radios available online. Start with a duckduckgo
search of 'rf tube circuits' and you'll stay busy for months.
And ask around locally for help. There's bound to be one or
two old dinosaurs in the vicinity who own tube rigs and can
help you out.
And finally, read the archives for this mailing list. All of it!
You won't find that amount of domain-specific knowledge about
Drake radios anywhere else on the internet.
Don't fret that the radio isn't fully functional. The joy of
tube rigs is they are *repairable*! Take your time, learn the
tube technology, and before long you'll be able to fix that
rig yourself. Okay, maybe with some help from people on this
mailing list :-)
--lyndon
|
Re: New to me drake 4 twins
Yes, those convertors are rare in the US.? Most of the ones I've heard about are in Europe/UK because they have LW broadcasters there (or at least they did back then!).
I'll take this opportunity to warn about going inside these rigs if you're not used to tube circuits.? The receivers have as much as 160 VDC inside them (a nasty bite, at least, and the potential to be fatal) and the transmitter has 250 VDC all over the place underneath and up to 750 VDC where the plate supply for the PA comes in.? That is definitely enough to kill you.
The equipment is easy to use, once you know how.? One thing with the receiver is that you will want to put a shorting plug into the MUTE jack -- or -- connect the two boxes together so that the receiver is not muted.? You should be able to hear signals, however, with the receiver turned to "ON".? You won't be able to hear the calibrator.
73,
Steve Wedge, W1ES/4
Time flies like an arrow.? Fruit flies like a banana.
Sent with secure email.
On Tuesday, January 9th, 2024 at 11:56 AM, n4buq <n4buq@...> wrote:
There's a Drake 2-LF, a low-frequency converter for the 2 A/B/C but not sure if there was a 4-LF.
Thanks, Barry - N4BUQ
From: "David" <david.w5xu@...>
To: "DRAKE-RADIO" <[email protected]>
Sent: Tuesday, January 9, 2024 10:31:23 AM
Subject: Re: [DRAKE-RADIO] New to me drake 4 twins
Ryan: I am about 4 hours from you in Covington, LA.? Package it up and come over and I will help you in any way I can.? ?Assume you have all the manuals and stuff as that. Not sure what that plug in is for.? But we can look at that as well. The Drake B line s a favorite of many Darke users. It is a capable radio even in these times. David Assaf III
W5XU??? VP8RXU
New to the group and?I just came into an old Drake 4B set. This radio set is super cool, turns on, transmits (although I don¡¯t know where) and the amp is pristine and quite easily put out 1kw when I drove it with a different radio. I¡¯d love to keep it and make it work again, but it¡¯s so far before my time that I really don¡¯t know what I¡¯m looking at, if you want to know the truth. Originally licensed in 1993 and this gear was old then!? This is my first tube type anything to try and use.
I have the power supply for the radio set and the power supply for the amp and I¡¯d like to keep this set together. I¡¯ve had several people ask me how much I want for it but I think I want to keep it. Besides, eBay is the only place I¡¯ve looked to find a value and I don¡¯t know what category this set would fall into, working, parts only, etc. One guy offered me $100 for the radio set and power supply, but I¡¯ll box it up and put it in the attic for that much!? It¡¯s just so cool. I was surprised by the color of the meter backlights too, what a treat!? The amp looks super cool as well!
Problem I have is it really won¡¯t fit into how I currently operate, so I¡¯m still on the fence about keeping it or passing it on. ?I¡¯ve been learning all I can but I know when my knowledge limit has been reached. I¡¯m considering keeping it as a full on restoration project, though it already looks super clean on the outside and the inside. I did an internet search for drake restoration and found a few websites dedicated to it. So it occurred to me that I might be inclined to send it off for rework if it needs it.?
So far, I am unable to get any speaker audio, not even a crackle. I tested the speaker with a 9v battery and it made noise. I ohmed out the cord at 3.5ohm. So I suspect maybe the socket on the receiver is bad. I don¡¯t know. I can make it transmit, it puts out about 125w into a dummy load when I peak it with a calibrated ARRL whistle, but I really don¡¯t know what I¡¯m doing and don¡¯t hear anything on my shack radio on the freq I think I¡¯m transmitting on. It¡¯s very likely operator error, but I¡¯d like any opinions or advice someone can offer me.?
There¡¯s also this little circuit board that was plugged into the back accessory port thats a drake 4-LF, but I can¡¯t find any info on it. I actually have the leaflet for it from Drake, but it¡¯s beyond my knowledge. To be honest, I haven¡¯t the slightest idea what it¡¯s supposed to do or if it was an option or aftermarket or anything. There just doesn¡¯t seem to be much info on the web about it, so hopefully someone on here can shed some light on this thing.??
I¡¯ll be happy to post pictures or send them to someone individually if it at all helps. I¡¯m not much for being on message boards, or any social media to be honest, and it¡¯s unlikely I¡¯d be able to offer anyone here any value unless you need me to climb your tower!
So thanks in advance for your time and anything someone can offer me.
warmest regards and 73
Ryan Jones
Beaumont TX?
NV5E
|
Re: New to me drake 4 twins
There's a Drake 2-LF, a low-frequency converter for the 2 A/B/C but not sure if there was a 4-LF.
Thanks, Barry - N4BUQ
From: "David" <david.w5xu@...>
To: "DRAKE-RADIO" <[email protected]>
Sent: Tuesday, January 9, 2024 10:31:23 AM
Subject: Re: [DRAKE-RADIO] New to me drake 4 twins
Ryan: I am about 4 hours from you in Covington, LA.? Package it up and come over and I will help you in any way I can.? ?Assume you have all the manuals and stuff as that. Not sure what that plug in is for.? But we can look at that as well. The Drake B line s a favorite of many Darke users. It is a capable radio even in these times. David Assaf III
W5XU??? VP8RXU
New to the group and?I just came into an old Drake 4B set. This radio set is super cool, turns on, transmits (although I don¡¯t know where) and the amp is pristine and quite easily put out 1kw when I drove it with a different radio. I¡¯d love to keep it and make it work again, but it¡¯s so far before my time that I really don¡¯t know what I¡¯m looking at, if you want to know the truth. Originally licensed in 1993 and this gear was old then!? This is my first tube type anything to try and use.
I have the power supply for the radio set and the power supply for the amp and I¡¯d like to keep this set together. I¡¯ve had several people ask me how much I want for it but I think I want to keep it. Besides, eBay is the only place I¡¯ve looked to find a value and I don¡¯t know what category this set would fall into, working, parts only, etc. One guy offered me $100 for the radio set and power supply, but I¡¯ll box it up and put it in the attic for that much!? It¡¯s just so cool. I was surprised by the color of the meter backlights too, what a treat!? The amp looks super cool as well!
Problem I have is it really won¡¯t fit into how I currently operate, so I¡¯m still on the fence about keeping it or passing it on. ?I¡¯ve been learning all I can but I know when my knowledge limit has been reached. I¡¯m considering keeping it as a full on restoration project, though it already looks super clean on the outside and the inside. I did an internet search for drake restoration and found a few websites dedicated to it. So it occurred to me that I might be inclined to send it off for rework if it needs it.?
So far, I am unable to get any speaker audio, not even a crackle. I tested the speaker with a 9v battery and it made noise. I ohmed out the cord at 3.5ohm. So I suspect maybe the socket on the receiver is bad. I don¡¯t know. I can make it transmit, it puts out about 125w into a dummy load when I peak it with a calibrated ARRL whistle, but I really don¡¯t know what I¡¯m doing and don¡¯t hear anything on my shack radio on the freq I think I¡¯m transmitting on. It¡¯s very likely operator error, but I¡¯d like any opinions or advice someone can offer me.?
There¡¯s also this little circuit board that was plugged into the back accessory port thats a drake 4-LF, but I can¡¯t find any info on it. I actually have the leaflet for it from Drake, but it¡¯s beyond my knowledge. To be honest, I haven¡¯t the slightest idea what it¡¯s supposed to do or if it was an option or aftermarket or anything. There just doesn¡¯t seem to be much info on the web about it, so hopefully someone on here can shed some light on this thing.??
I¡¯ll be happy to post pictures or send them to someone individually if it at all helps. I¡¯m not much for being on message boards, or any social media to be honest, and it¡¯s unlikely I¡¯d be able to offer anyone here any value unless you need me to climb your tower!
So thanks in advance for your time and anything someone can offer me.
warmest regards and 73
Ryan Jones
Beaumont TX?
NV5E
|
Re: New to me drake 4 twins
Ryan: I am about 4 hours from you in Covington, LA.? Package it up and come over and I will help you in any way I can.? ?Assume you have all the manuals and stuff as that. Not sure what that plug in is for.? But we can look at that as well. The Drake B line s a favorite of many Darke users. It is a capable radio even in these times.
David Assaf III
W5XU??? VP8RXU
New to the group and?I just came into an old Drake 4B set. This radio set is super cool, turns on, transmits (although I don¡¯t know where) and the amp is pristine and quite easily put out 1kw when I drove it with a different radio. I¡¯d love to keep it and make it work again, but it¡¯s so far before my time that I really don¡¯t know what I¡¯m looking at, if you want to know the truth. Originally licensed in 1993 and this gear was old then!? This is my first tube type anything to try and use.
I have the power supply for the radio set and the power supply for the amp and I¡¯d like to keep this set together. I¡¯ve had several people ask me how much I want for it but I think I want to keep it. Besides, eBay is the only place I¡¯ve looked to find a value and I don¡¯t know what category this set would fall into, working, parts only, etc. One guy offered me $100 for the radio set and power supply, but I¡¯ll box it up and put it in the attic for that much!? It¡¯s just so cool. I was surprised by the color of the meter backlights too, what a treat!? The amp looks super cool as well!
Problem I have is it really won¡¯t fit into how I currently operate, so I¡¯m still on the fence about keeping it or passing it on. ?I¡¯ve been learning all I can but I know when my knowledge limit has been reached. I¡¯m considering keeping it as a full on restoration project, though it already looks super clean on the outside and the inside. I did an internet search for drake restoration and found a few websites dedicated to it. So it occurred to me that I might be inclined to send it off for rework if it needs it.?
So far, I am unable to get any speaker audio, not even a crackle. I tested the speaker with a 9v battery and it made noise. I ohmed out the cord at 3.5ohm. So I suspect maybe the socket on the receiver is bad. I don¡¯t know. I can make it transmit, it puts out about 125w into a dummy load when I peak it with a calibrated ARRL whistle, but I really don¡¯t know what I¡¯m doing and don¡¯t hear anything on my shack radio on the freq I think I¡¯m transmitting on. It¡¯s very likely operator error, but I¡¯d like any opinions or advice someone can offer me.?
There¡¯s also this little circuit board that was plugged into the back accessory port thats a drake 4-LF, but I can¡¯t find any info on it. I actually have the leaflet for it from Drake, but it¡¯s beyond my knowledge. To be honest, I haven¡¯t the slightest idea what it¡¯s supposed to do or if it was an option or aftermarket or anything. There just doesn¡¯t seem to be much info on the web about it, so hopefully someone on here can shed some light on this thing.??
I¡¯ll be happy to post pictures or send them to someone individually if it at all helps. I¡¯m not much for being on message boards, or any social media to be honest, and it¡¯s unlikely I¡¯d be able to offer anyone here any value unless you need me to climb your tower!
So thanks in advance for your time and anything someone can offer me.
warmest regards and 73
Ryan Jones
Beaumont TX?
NV5E
|
New to the group and?I just came into an old Drake 4B set. This radio set is super cool, turns on, transmits (although I don¡¯t know where) and the amp is pristine and quite easily put out 1kw when I drove it with a different radio. I¡¯d love to keep it and make it work again, but it¡¯s so far before my time that I really don¡¯t know what I¡¯m looking at, if you want to know the truth. Originally licensed in 1993 and this gear was old then! ?This is my first tube type anything to try and use.
I have the power supply for the radio set and the power supply for the amp and I¡¯d like to keep this set together. I¡¯ve had several people ask me how much I want for it but I think I want to keep it. Besides, eBay is the only place I¡¯ve looked to find a value and I don¡¯t know what category this set would fall into, working, parts only, etc. One guy offered me $100 for the radio set and power supply, but I¡¯ll box it up and put it in the attic for that much! ?It¡¯s just so cool. I was surprised by the color of the meter backlights too, what a treat! ?The amp looks super cool as well!
Problem I have is it really won¡¯t fit into how I currently operate, so I¡¯m still on the fence about keeping it or passing it on. ?I¡¯ve been learning all I can but I know when my knowledge limit has been reached. I¡¯m considering keeping it as a full on restoration project, though it already looks super clean on the outside and the inside. I did an internet search for drake restoration and found a few websites dedicated to it. So it occurred to me that I might be inclined to send it off for rework if it needs it.?
So far, I am unable to get any speaker audio, not even a crackle. I tested the speaker with a 9v battery and it made noise. I ohmed out the cord at 3.5ohm. So I suspect maybe the socket on the receiver is bad. I don¡¯t know. I can make it transmit, it puts out about 125w into a dummy load when I peak it with a calibrated ARRL whistle, but I really don¡¯t know what I¡¯m doing and don¡¯t hear anything on my shack radio on the freq I think I¡¯m transmitting on. It¡¯s very likely operator error, but I¡¯d like any opinions or advice someone can offer me.?
There¡¯s also this little circuit board that was plugged into the back accessory port thats a drake 4-LF, but I can¡¯t find any info on it. I actually have the leaflet for it from Drake, but it¡¯s beyond my knowledge. To be honest, I haven¡¯t the slightest idea what it¡¯s supposed to do or if it was an option or aftermarket or anything. There just doesn¡¯t seem to be much info on the web about it, so hopefully someone on here can shed some light on this thing.??
I¡¯ll be happy to post pictures or send them to someone individually if it at all helps. I¡¯m not much for being on message boards, or any social media to be honest, and it¡¯s unlikely I¡¯d be able to offer anyone here any value unless you need me to climb your tower!
So thanks in advance for your time and anything someone can offer me.
warmest regards and 73
Ryan Jones
Beaumont TX?
NV5E
|
Tim is right!? You have to tune to one side or the other (sort of like FM Slope-Detection)
Even doing that, it's not really going to sound all that good.
You really need a 6kHz filter (or maybe a 5)
Jeff Covelli (WA8SAJ) had a great write-up on that very thing using the outstanding Inrad filter for TR-6 purpose.
See:
Now having said all that, I wouldn't consider the TR-4 my "go-to " radio for operating AM.
I was very lucky to find one of these filters for my TR-6 and I was also VERY lucky that I bought the 2.5kHz(ssb) filters for my TR-4C because none of these filters are available anymore! If you find then used get them.? don't expect to get them cheap though
The one in my TR-6 works wonderfully on 6m AM.? (in the PNW, we have a WED/SUN 50.400 AM net that I sometimes check into)
The 2.5kHz filters make the TR-4 sound MUCH nicer on transmit and is a LOT easier on the ears for receive.
And, NO.? Neither of these filters are for sale at any price!!
Cheers,
--
73/Rick
W4XA
*Every post is created using Linux
|
Rob what you described other than what you call "distortion" is caused by the AM signal passing through the TR4C's 2.4 KHZ SSB filter, even the Drake manual says to tune off the signal to the best sounding audio. Now I can't remember the Electric Radio issue but there was an article about placing a wider filter in the TR4C ( an additional filter ) to provide better AM quality.'
Good luck
73 Tim WB8UHZ
On Monday, January 8, 2024 at 05:37:26 PM EST, Rob PA9Z <pa9z.groups.io@...> wrote:
Dear Group,
Now my T-4XC project is fininshed (for the moment :), it is time to tackle problem in my TR-4C. Or maybe there is no problem...., just me expecting too much?.? It's the audio quality in AM reception. Yes, I understand the AM signal is squeezed trough one of the SSB filters (wihich one?), but the AM audio still sounds distorted. Besides, the receiver sensitivity in AM is also significantly lower. I know, I should not compare the AM reception of a TR-4C with an R-4C, but still. And I don't have a reference to compare the AM performence with another TR-4C.
In AM Mode, the plate voltage of V2 (12AV6) working as the AM detector is only 80 Volts (compared to 200 Volts in SSB and CW, where V2 is a AF pre-amp). Is this 80 Volts normal?? Its due to a higher plate current through the 330k resistor feeding the plate of V2. Is this lower voltage maybe the cause of the bad audio quaility?
I have an 9 MHz AM filter laying around.? Does a mod exist where AM will be using a separate AM filter?
Your thoughts are again much appreciated.
73 Rob PA9Z
|
Dear Group,
Now my T-4XC project is fininshed (for the moment :), it is time to tackle problem in my TR-4C. Or maybe there is no problem...., just me expecting too much?.? It's the audio quality in AM reception. Yes, I understand the AM signal is squeezed trough one of the SSB filters (wihich one?), but the AM audio still sounds distorted. Besides, the receiver sensitivity in AM is also significantly lower. I know, I should not compare the AM reception of a TR-4C with an R-4C, but still. And I don't have a reference to compare the AM performence with another TR-4C.
In AM Mode, the plate voltage of V2 (12AV6) working as the AM detector is only 80 Volts (compared to 200 Volts in SSB and CW, where V2 is a AF pre-amp). Is this 80 Volts normal?? Its due to a higher plate current through the 330k resistor feeding the plate of V2. Is this lower voltage maybe the cause of the bad audio quaility?
I have an 9 MHz AM filter laying around.? Does a mod exist where AM will be using a separate AM filter?
Your thoughts are again much appreciated.
73 Rob PA9Z
|
Re: Pyramid IMP Paper Capacitor Smell
I have never heard of any paper capacitors being toxic. Notwithstanding that, it is a good idea to replace all paper capacitors. They weren¡¯t the greatest when they were new and they¡¯re now all at least 60 years old and worse than when new.?
There shouldn¡¯t be very many in a VTVM.?
73,
Steve Wedge, W1ES/4
Time flies like an arrow. Fruit flies like a banana.
On Mon, Jan 8, 2024 at 16:27, Michael Smith via groups.io < tw8kcabpilot@...> wrote: The Pyramid IMP paper-dielectric capacitors in my VTVM smell like moth balls, being the best way I know to describe it. ?I have had no problem with this VTVM operation, but I¡¯m wondering if this smell (a vapor of some kind) is hazardous to the health. ?Does anyone know if this capacitor contains PCBs, or is otherwise harmful to the health?
Thank you.
73, Michael Smith, N4KZO
|
Pyramid IMP Paper Capacitor Smell
The Pyramid IMP paper-dielectric capacitors in my VTVM smell like moth balls, being the best way I know to describe it. ?I have had no problem with this VTVM operation, but I¡¯m wondering if this smell (a vapor of some kind) is hazardous to the health. ?Does anyone know if this capacitor contains PCBs, or is otherwise harmful to the health?
Thank you.
73, Michael Smith, N4KZO
|
Re: TR7 Getting ready to sell. But have to deal with the dastardly DR7 board again. I thought.
Lately I've been using CRC that I can get at my local Ace Hardware stores. 73 -Jim NU0C On Mon, 08 Jan 2024 02:46:38 -0800 "Bill via groups.io" <billnopic@...> wrote: On Sat, Jan 6, 2024 at 03:31 PM, Jim Shorney wrote:
good non-contaminating spray
Jim,
What is your recommendation for a " good non-contaminating spray"?
Thanks
Bill
W4WCS
|
Re: need to know the values of rfc-3 choke
Which type of rig: transmitter or transceiver? ?I probably have one.?
Steve Wedge, W1ES/4
Time flies like an arrow. Fruit flies like a banana.
On Mon, Jan 8, 2024 at 10:39, Tim KD0KIO < info@...> wrote: Re: need to know the values of rfc-3 choke? sorry about the typo that was RFC ¨C3
|
Re: need to know the values of rfc-3 choke
Re: need to know the values of rfc-3 choke? sorry about the typo that was RFC ¨C3
|
need to know the values of rf-3 choke
good morning gentlemen my name is Tim and I own a Drake T4 XP transmitter. I am replacing the two 6JB6 tubes and the two 15 omes 1 W resistors. When I'm looking at my schematic there is a choke that I need to replace RFC-3 but I can't find the values of that choke. My question is does anybody know the values of this choke and need to know the owns/ millihenries /and the current any help will be appreciated you can also email me at info@... 73's Tim
|
Re: TR7 Getting ready to sell. But have to deal with the dastardly DR7 board again. I thought.
On Sat, Jan 6, 2024 at 03:31 PM, Jim Shorney wrote:
good non-contaminating spray
Jim, What is your recommendation for a " good non-contaminating spray"?
Thanks
Bill
W4WCS
|
Re: TR7 Getting ready to sell. But have to deal with the dastardly DR7 board again. I thought.
Thanks Jerry,
With my present state of dexterity and vision. Not sure if I may do more damage. Looking at the problem, I can't reach more than about 35% of the contacts if I'm lucky. Without doing a partial tear down. I am considering my options.
73
Bill
W4WCS?
|
Drake Technical Net - 7 January 2024
The Drake Technical Net met at 21:00z on Sunday, 7 January 2024 ? There were 40 stations checking in with us, today. The Drake radios used included the following: ? >> Drake Twins (all models): 15 ? >> Drake TR-3 Transceivers: 0 ? >> Drake TR-4 Transceivers (all models): 8 ? >> Drake TR5 Transceivers: 2 ? >> Drake TR7 / TR7A Transceivers: 7 ? The net operated under very good conditions and did not close until 22:26z. ? Join us again on Sunday, 14 January 2024 at 21:00z (4:00 PM EST, 3:00 CST). Net Control will be Ron Baker, WB4HFN. ? 73, ? Bill Shadid, W9MXQ Drake Technical Net ¨C Net Control for 7 January 2024 W9MXQ@... ?
|
Nice catch Giuliano! I wonder if you had a component with a bare lead too close to the back of a female connector somewhere. The male Molex pins are very long and can protrude from the rear of the board connector where some components are packed very close. I have had this happen. 73 -Jim NU0C On Sat, 06 Jan 2024 02:09:39 -0800 "Giuliano Lauto via groups.io" <la_uto@...> wrote: Happy new year dear friends!
Had some time to spend, the TR7 is now fixed.
As Jim suggested, I could not find any obvious fault in the VCO board.
I think the fault was due to the very tight boards compartments which likely resulted in erratic contacts at the bottom of VCO and TX exciter boards.
I corrected them by inserting a cartoon insulator at bottom of each board. The PLL now works perfectly
Another interesting? finding is that the 500 Khz signal from the programmable divider to the phase comparator, pin 5/11, is not a square wave, as the manual suggests,? but a 2 uS pulse of variable width. The higher the band, the shorter the pulse. Please have a look at photos posted here:
/g/DRAKE-RADIO/album?id=292102
Vr
Giuliano, IV3DLW
-- 73 -Jim NU0C
|
David
Rob PA9Z
Jim Shorney
Bill