On Sat, 28 Dec 2024 08:51:26 -0800 "Jim VE7RF via groups.io" <jim.thom@...> wrote: ##? The HV probe just arrived yesterday.? ?They stipulate? that if the return lead goes open, yes, you will end up with full B+ on the return test lead.? ?You will also end up with full? B+ on both? the red / black test leads that plug into the fluke 87.? ?And if the cold end, (smaller 1.1 meg resistor) opens up, you will have full B+ on the red lead...that goes to the fluke 87 DVM.? They tell you to connect the grnd return lead 1st, then the dvm red / black leads, then turn on B+ supply, then attach the probe...last. Yes, that is all correct. This is old tech that has been around since television sets became consumer commodities and they are robustly built (if you got a good one) for good reason. No one wants to get sued because a TV technician electrocuted himself with a poorly built probe. :) You are only in danger if you are part of the return path. Which you should not be. The meter is only in danger if that low resistor opens up and there is a return path, which could happen if the low resistor opens up while the meter is connected to the DUT. When I first got mine I used it with my Fluke 8050A running on battery power. After I got the 289 I retired the dual power 8050A in favor of one that did not have the battery option so I wouldn't have to deal with NiCAD maintenance. It is still my master bench meter but as often as not I grab the 289 when I am working. Using the power on, extra digit option on the fluke 87 DVM,? it will read down to 1 volt increments, like 2650, 2650 vdc etc.? ? Without the power on option, it reads in 10 V increments. Such precision is really not necessary at those voltage levels. The calibration of the probe may not even support it. Mine does have a calibration pot in the low end. I calibrated it for my Fluke 289 at 120V AC and that is more than good enough. Really it was "close enough" to start with. The input impedance of the meter becomes part of the voltage divider so it is only accurate with meters of similar input impedances. -- 73 -Jim NU0C
|
On Tue, Dec 24, 2024 at 02:40 PM, Jim Shorney wrote:
<It shouldn't unless your Fluke has a metal case. There is no return path with a non-metallic enclosure so both you and the meter should be OK. What could cause damage would be the cold end resistor opening up. I've <had one of these probes for years. They used to be standard equipment in TV repair shops. Even given what I wrote above the only thing I touch when doing a measurement is the probe handle and I do not use a mains <powered meter.
<On Tue, 24 Dec 2024 04:52:04 -0800
<"Jim VE7RF via groups.io" <jim.thom@...> wrote:
<IF that return test lead ( that goes to the B- of the supply)? ever opened up / fell off....... the full B+ will then appear on the fluke 87 DVM.? This freaks me out.
--
<73
<-Jim
<NU0C
##? The HV probe just arrived yesterday.? ?They stipulate? that if the return lead goes open, yes, you will end up with full B+ on the return test lead.? ?You will also end up with full? B+ on both? the red / black test leads that plug into the fluke 87.? ?And if the cold end, (smaller 1.1 meg resistor) opens up, you will have full B+ on the red lead...that goes to the fluke 87 DVM.? They tell you to connect the grnd return lead 1st, then the dvm red / black leads, then turn on B+ supply, then attach the probe...last.? Drawn out on paper, it's just a 1000 megohm resistor in series with a 1.1 megohm resistor...then the grnd return.? The V drop across the smaller resistor is applied to the DVM.? ? I measured? the resistance of the bigger resistor (Between tip of probe + RED test lead).? ?Then measured the smaller value resistor? ( between the red / black test leads).? ? Then the total resistance ( between probe tip and grnd return).? Point is, you could have any of this stuff go open....... and think there is zero HV...... when actually there is HV present.? ? Mine came with 3 x different types of tips.? Tapered pointed type.? 2nd one is a looped hook.? ?3rd one is a angled flat metal piece, with an arc cut out.... made to engage the threads of machine screws.? ?The 2nd and 3rd types will never slip, or slide off, like the? 1st type.? Using the power on, extra digit option on the fluke 87 DVM,? it will read down to 1 volt increments, like 2650, 2650 vdc etc.? ? Without the power on option, it reads in 10 V increments.? It works good, but I would caution folks using them, to be very careful.?? Jim? ?VE7RF
|
Re: TR-4C problem on 40 meters
Steve, I smelt no smoke and saw no burnt resistor.
As far as I can see from the schematic only the following parts are used on 40 meters: L1, T3, C4 and C7 (inside T3), T8 and T10 - and of course the 21.5 MHz xtal.
Peter OZ8CTH
|
Thanks Gary and Jim. On the radio working I don't remember having it up on those two bands before but I expect it did work. In cleaning the female connectors on the VCO board I used a GUM Proxabrush go-between to clean them with some D5. Didn't notice anyones that the brush went in and out easily. But I will check them again. I will also check the pins in the DR7 to make sure they are all okay.?
73, Jim VE1RB
On Fri, Dec 27, 2024 at 9:06?PM Gary Follett via <xntrick1948= [email protected]> wrote: It is worth asking, did the failure of your VCO board (displaying 51.950) occur on its own? That is to ask, did the radio work properly and then just fail or has it, as long as you have had it, always operated with this fault??
If it once worked for you and then failed, then it would make sense to see what gets disconnected if those pins are not in line ?and look for a way that same thing could happen without the pin alignment problem.
The pin alignment fix is pretty easy though, if the board alignment is the cause. It just SOUNDS difficult.
That whole DR7 was always a source of issues due to its complexity and difficulty of installation. I don’t know how a DR7 could even endure the stresses of removal and reinsertion more than once!
Gary?
W0DVN
Thanks Tom. I printed that off but hope that is not the problem.
73, Jim VE1RB In 2010 there was a thread regarding the Drake TR-7 display showing 51950.0 on the old retired Drakelist.
The thread is archived at?
Please click the link so the owner knows that we find the archive useful.
Hope this helps. Tom, AG9X
================? Below are the posts from Brian Koontz WA3ITE, Jim Shorney NU0C and Garey Barrell K4OAH (SK)? (just in case Drake TR-7 DR-7 problems outlive the??site)
Re: [Drakelist] Almost there: TR-7 display issues -- FIXED!
Brian Koontz Fri, 30 Jul 2010 20:36:54 -0700
Well, the TR-7 from hell is now a fully operational TR-7 from hell!
In preparation for some signal tracing, I decided to extend the DR-7
board using the extenders I have.? To do this, you have to unmount the
two voltage regulators mounted to the chassis, and jumper the
connector farthest to the right. ?(I didn't bother connecting the
up/down band buttons.) ?Lo and behold, the display worked!?
Some further investigation revealed that the chassis has warped over
the years, so the two 3-prong connectors on the VCO board were no
longer in a horizontal line.? So I was determined to make sure the
board was fully seated on all the connectors.
To do this, I had to drop the front panel.? Not a major chore, just
one knob to remove (the band knob) and 6 side screws. With that now
out of the way, it was an easy job to determine if all the pins were
where they belonged.? The only snag was that the front panel, when
canted downwards, angles the PTO can upwards.? So you have to hold the
front panel perpendicular and steady with slight downward pressure to
fully seat the board.? Once all the pins were visually confirmed to be
seated, I remounted the front panel, reattached the regulators and all
the connectors, and fired the rig up.? Everything now seems to work!
It turns out the original DR-7 board was indeed defective as well
(possibly because it had been seated incorrectly).? And a visual
confirmation from topside indicates the chassis is, indeed, warped:
The screw hole is misaligned with the mounting hole in the board.?
So, for archival purposes in case anyone else decides to search for
this problem: ?If the display if fixed on "51950", one possible cause
is that one or more DR-7 pins, possibly the VCO pins, are not
correctly seated.? The best solution is to drop the front panel and
confirm visually that the pins are fully seated.
Now it's time to get on the air!
??--Brian/WA3ITE
=================?
Jim Shorney Fri, 30 Jul 2010 23:17:58 -0700
On Fri, 30 Jul 2010 20:40:52 -0500, Brian Koontz wrote:
>Well, the TR-7 from hell is now a fully operational TR-7 from hell!
>
>Now it's time to get on the air!
Congratulations, Brian! You have been assimilated into the collective.
Resistance is futile.
73
-Jim
================= ? Garey Barrell ?k4oah@...?via ?Sat, Jul 31, 2010, 8:34?AM to drakelist Brian Koontz wrote: > Some further investigation revealed that the chassis has warped over > the years, so the two 3-prong connectors on the VCO board were no > longer in a horizontal line.? So I was determined to make sure the > board was fully seated on all the connectors. > > > > So, for archival purposes in case anyone else decides to search for > this problem: ?If the display is fixed on "51950", one possible cause > is that one or more DR-7 pins, possibly the VCO pins, are not > correctly seated.? The best solution is to drop the front panel and > confirm visually that the pins are fully seated. >
Brian -
Congratulations!! ? It's always nice when one 'comes together'.
Just as an aside, someone suggested earlier (and correctly) that the
"51950" problem may indicate a loss of the 500 kHz reference signal.?
You might find it interesting that the left-most three pin connector on
the VCO board is the 500 kHz reference signal!
Those pins on the bottom of the DR-7 are ALWAYS a problem, ya' just
can't see 'em!!
Your 'trials' have been an interesting 'trip' for others, thanks for
documenting it for us all.
73, Garey - K4OAH
Glen Allen, VA
Drake 2-B, 4-B, C-Line& ?TR-4/C Service Supplement CDs
<>
=================
? Search terms to make this post easier to find:? Drake TR-7 TR7 DR-7 DR7 display frozen locked stuck ? 51950?? 51,950?? 51 950?? 5195? 51950.0 ? 51,950.0 ? 51 950 0
???
|
Ah yes, a Molex issue. I knew I had seen that somewhere before but did not think to check Drakelist. Another thing to do is inspect the female connectors looking into the pin holes. If you see a large gap between the springy bit (another technical term) and the inside wall of the connector that pin may not be making good connection. The connector will need to be re-tensioned or replaced. The female connectors are vulnerable to this with the usual way the DR7 is removed and re-installed. A better way is to angle the front panel forward using the method described in the service manual as part of the procedure to access the PTO. Then it is a straight up and down for the DR7. Another point of concern is the male pins that have circuit connections on the bottom side of the DR7 board. If the vias are not well flowed through with solder to the bottom side this becomes a stress point for the same reason stated above and may go intermittent or open circuit. And as I have stated before a few times, on boards this old I never trust a via! The bottom connections are not hard to get to, you can gently pry the plastic pin retainer up away from the circuit board far enough not to melt it but not so far as to fall off. If you have to take the VCO or Translator boards out there is another connector check you can make. Components on the boards are packed pretty tightly and it is possible for a component to be bent too close to the back of a female connector and potentially short to the end of the male pin poking through. I don't think I have seen this as a latent defect but it can happen when someone is working on a board. The left rear corner f the DR7 is prone to being pushed down just a little too far and shorting to something. Fortunately it doesn't let out any smoke. I like to put a couple of small flat sticky rubber feet in that spot as bumpers to restrict how far the pins can be pushed in. On Fri, 27 Dec 2024 18:05:10 -0600 "Tom Evans via groups.io" <Tom.AG9X@...> wrote: In 2010 there was a thread regarding the Drake TR-7 display showing 51950.0
on the old retired Drakelist.
The thread is archived at
Please click the link so the owner knows that we find the archive useful.
Hope this helps.
Tom, AG9X -- 73 -Jim NU0C
|
Gary- About 50mA, keying in CW mode. In Tune mode, about 90-100mA.
Do you get idle plate current when you key the radio?
Gary
W0DVN
Gary- Using an AC4-R supply. PA plate, plate, filament, dial light and bias voltages are getting to the T4XC. Dead driver or finals?
There was a reason the power supply fuse popped. Check voltages there first.
Gary W0DVN
Group, I'd welcome any advice on where to start looking.??
The 5A fuse on the AC4 blew in my absence. Replaced the fuse, and cannot get a peak greater than 0.1A when switching from SSB to tune, regardless of the gain setting on 80 and 40.??
D'oh.....? ??
73 Jay
|
Do you get idle plate current when you key the radio?
Gary
toggle quoted message
Show quoted text
On Dec 27, 2024, at 7:00?PM, Jay W6CJ via groups.io <lastradioman@...> wrote:
Gary- Using an AC4-R supply. PA plate, plate, filament, dial light and bias voltages are getting to the T4XC. Dead driver or finals?
There was a reason the power supply fuse popped. Check voltages there first.
Gary W0DVN
Group, I'd welcome any advice on where to start looking.??
The 5A fuse on the AC4 blew in my absence. Replaced the fuse, and cannot get a peak greater than 0.1A when switching from SSB to tune, regardless of the gain setting on 80 and 40.??
D'oh.....? ??
73 Jay
|
It is worth asking, did the failure of your VCO board (displaying 51.950) occur on its own? That is to ask, did the radio work properly and then just fail or has it, as long as you have had it, always operated with this fault??
If it once worked for you and then failed, then it would make sense to see what gets disconnected if those pins are not in line ?and look for a way that same thing could happen without the pin alignment problem.
The pin alignment fix is pretty easy though, if the board alignment is the cause. It just SOUNDS difficult.
That whole DR7 was always a source of issues due to its complexity and difficulty of installation. I don’t know how a DR7 could even endure the stresses of removal and reinsertion more than once!
Gary?
toggle quoted message
Show quoted text
On Dec 27, 2024, at 6:25?PM, Jim Harris via groups.io <radiove1rb@...> wrote:
Thanks Tom. I printed that off but hope that is not the problem.
73, Jim VE1RB In 2010 there was a thread regarding the Drake TR-7 display showing 51950.0 on the old retired Drakelist.
The thread is archived at?
Please click the link so the owner knows that we find the archive useful.
Hope this helps. Tom, AG9X
================? Below are the posts from Brian Koontz WA3ITE, Jim Shorney NU0C and Garey Barrell K4OAH (SK)? (just in case Drake TR-7 DR-7 problems outlive the??site)
Re: [Drakelist] Almost there: TR-7 display issues -- FIXED!
Brian Koontz Fri, 30 Jul 2010 20:36:54 -0700
Well, the TR-7 from hell is now a fully operational TR-7 from hell!
In preparation for some signal tracing, I decided to extend the DR-7
board using the extenders I have.? To do this, you have to unmount the
two voltage regulators mounted to the chassis, and jumper the
connector farthest to the right. ?(I didn't bother connecting the
up/down band buttons.) ?Lo and behold, the display worked!?
Some further investigation revealed that the chassis has warped over
the years, so the two 3-prong connectors on the VCO board were no
longer in a horizontal line.? So I was determined to make sure the
board was fully seated on all the connectors.
To do this, I had to drop the front panel.? Not a major chore, just
one knob to remove (the band knob) and 6 side screws. With that now
out of the way, it was an easy job to determine if all the pins were
where they belonged.? The only snag was that the front panel, when
canted downwards, angles the PTO can upwards.? So you have to hold the
front panel perpendicular and steady with slight downward pressure to
fully seat the board.? Once all the pins were visually confirmed to be
seated, I remounted the front panel, reattached the regulators and all
the connectors, and fired the rig up.? Everything now seems to work!
It turns out the original DR-7 board was indeed defective as well
(possibly because it had been seated incorrectly).? And a visual
confirmation from topside indicates the chassis is, indeed, warped:
The screw hole is misaligned with the mounting hole in the board.?
So, for archival purposes in case anyone else decides to search for
this problem: ?If the display if fixed on "51950", one possible cause
is that one or more DR-7 pins, possibly the VCO pins, are not
correctly seated.? The best solution is to drop the front panel and
confirm visually that the pins are fully seated.
Now it's time to get on the air!
??--Brian/WA3ITE
=================?
Jim Shorney Fri, 30 Jul 2010 23:17:58 -0700
On Fri, 30 Jul 2010 20:40:52 -0500, Brian Koontz wrote:
>Well, the TR-7 from hell is now a fully operational TR-7 from hell!
>
>Now it's time to get on the air!
Congratulations, Brian! You have been assimilated into the collective.
Resistance is futile.
73
-Jim
================= ? Garey Barrell ?k4oah@...?via ?Sat, Jul 31, 2010, 8:34?AM to drakelist Brian Koontz wrote: > Some further investigation revealed that the chassis has warped over > the years, so the two 3-prong connectors on the VCO board were no > longer in a horizontal line.? So I was determined to make sure the > board was fully seated on all the connectors. > > > > So, for archival purposes in case anyone else decides to search for > this problem: ?If the display is fixed on "51950", one possible cause > is that one or more DR-7 pins, possibly the VCO pins, are not > correctly seated.? The best solution is to drop the front panel and > confirm visually that the pins are fully seated. >
Brian -
Congratulations!! ? It's always nice when one 'comes together'.
Just as an aside, someone suggested earlier (and correctly) that the
"51950" problem may indicate a loss of the 500 kHz reference signal.?
You might find it interesting that the left-most three pin connector on
the VCO board is the 500 kHz reference signal!
Those pins on the bottom of the DR-7 are ALWAYS a problem, ya' just
can't see 'em!!
Your 'trials' have been an interesting 'trip' for others, thanks for
documenting it for us all.
73, Garey - K4OAH
Glen Allen, VA
Drake 2-B, 4-B, C-Line& ?TR-4/C Service Supplement CDs
<>
=================
? Search terms to make this post easier to find:? Drake TR-7 TR7 DR-7 DR7 display frozen locked stuck ? 51950?? 51,950?? 51 950?? 5195? 51950.0 ? 51,950.0 ? 51 950 0
???
|
Gary- Using an AC4-R supply. PA plate, plate, filament, dial light and bias voltages are getting to the T4XC. Dead driver or finals?
There was a reason the power supply fuse popped. Check voltages there first.
Gary W0DVN
Group, I'd welcome any advice on where to start looking.??
The 5A fuse on the AC4 blew in my absence. Replaced the fuse, and cannot get a peak greater than 0.1A when switching from SSB to tune, regardless of the gain setting on 80 and 40.??
D'oh.....? ??
73 Jay
|
Thanks Tom. I printed that off but hope that is not the problem.
73, Jim VE1RB
In 2010 there was a thread regarding the Drake TR-7 display showing 51950.0 on the old retired Drakelist.
The thread is archived at
Please click the link so the owner knows that we find the archive useful.
Hope this helps. Tom, AG9X
================
Below are the posts from Brian Koontz WA3ITE, Jim Shorney NU0C and Garey Barrell K4OAH (SK)? (just in case Drake TR-7 DR-7 problems outlive the site)
Re: [Drakelist] Almost there: TR-7 display issues -- FIXED!
Brian Koontz Fri, 30 Jul 2010 20:36:54 -0700
Well, the TR-7 from hell is now a fully operational TR-7 from hell!
In preparation for some signal tracing, I decided to extend the DR-7
board using the extenders I have.? To do this, you have to unmount the
two voltage regulators mounted to the chassis, and jumper the
connector farthest to the right. ?(I didn't bother connecting the
up/down band buttons.) ?Lo and behold, the display worked!
Some further investigation revealed that the chassis has warped over
the years, so the two 3-prong connectors on the VCO board were no
longer in a horizontal line.? So I was determined to make sure the
board was fully seated on all the connectors.
To do this, I had to drop the front panel.? Not a major chore, just
one knob to remove (the band knob) and 6 side screws. With that now
out of the way, it was an easy job to determine if all the pins were
where they belonged.? The only snag was that the front panel, when
canted downwards, angles the PTO can upwards.? So you have to hold the
front panel perpendicular and steady with slight downward pressure to
fully seat the board.? Once all the pins were visually confirmed to be
seated, I remounted the front panel, reattached the regulators and all
the connectors, and fired the rig up.? Everything now seems to work!
It turns out the original DR-7 board was indeed defective as well
(possibly because it had been seated incorrectly).? And a visual
confirmation from topside indicates the chassis is, indeed, warped:
The screw hole is misaligned with the mounting hole in the board.
So, for archival purposes in case anyone else decides to search for
this problem: ?If the display if fixed on "51950", one possible cause
is that one or more DR-7 pins, possibly the VCO pins, are not
correctly seated.? The best solution is to drop the front panel and
confirm visually that the pins are fully seated.
Now it's time to get on the air!
? --Brian/WA3ITE
=================
Jim Shorney Fri, 30 Jul 2010 23:17:58 -0700
On Fri, 30 Jul 2010 20:40:52 -0500, Brian Koontz wrote:
>Well, the TR-7 from hell is now a fully operational TR-7 from hell!
>
>Now it's time to get on the air!
Congratulations, Brian! You have been assimilated into the collective.
Resistance is futile.
73
-Jim
=================
? Garey Barrell k4oah@... via Sat, Jul 31, 2010, 8:34?AM to drakelist Brian Koontz wrote: > Some further investigation revealed that the chassis has warped over > the years, so the two 3-prong connectors on the VCO board were no > longer in a horizontal line.? So I was determined to make sure the > board was fully seated on all the connectors. > > > > So, for archival purposes in case anyone else decides to search for > this problem: ?If the display is fixed on "51950", one possible cause > is that one or more DR-7 pins, possibly the VCO pins, are not > correctly seated.? The best solution is to drop the front panel and > confirm visually that the pins are fully seated. >
Brian -
Congratulations!! ? It's always nice when one 'comes together'.
Just as an aside, someone suggested earlier (and correctly) that the
"51950" problem may indicate a loss of the 500 kHz reference signal.
You might find it interesting that the left-most three pin connector on
the VCO board is the 500 kHz reference signal!
Those pins on the bottom of the DR-7 are ALWAYS a problem, ya' just
can't see 'em!!
Your 'trials' have been an interesting 'trip' for others, thanks for
documenting it for us all.
73, Garey - K4OAH
Glen Allen, VA
Drake 2-B, 4-B, C-Line& ?TR-4/C Service Supplement CDs
<>
=================
? Search terms to make this post easier to find:? Drake TR-7 TR7 DR-7 DR7 display frozen locked stuck ? 51950?? 51,950?? 51 950?? 5195?
51950.0 ? 51,950.0 ? 51 950 0
??
|
In 2010 there was a thread regarding the Drake TR-7 display showing 51950.0 on the old retired Drakelist.
The thread is archived at
Please click the link so the owner knows that we find the archive useful.
Hope this helps. Tom, AG9X
================
Below are the posts from Brian Koontz WA3ITE, Jim Shorney NU0C and Garey Barrell K4OAH (SK)? (just in case Drake TR-7 DR-7 problems outlive the site)
Re: [Drakelist] Almost there: TR-7 display issues -- FIXED!
Brian Koontz Fri, 30 Jul 2010 20:36:54 -0700
Well, the TR-7 from hell is now a fully operational TR-7 from hell!
In preparation for some signal tracing, I decided to extend the DR-7
board using the extenders I have.? To do this, you have to unmount the
two voltage regulators mounted to the chassis, and jumper the
connector farthest to the right. ?(I didn't bother connecting the
up/down band buttons.) ?Lo and behold, the display worked!
Some further investigation revealed that the chassis has warped over
the years, so the two 3-prong connectors on the VCO board were no
longer in a horizontal line.? So I was determined to make sure the
board was fully seated on all the connectors.
To do this, I had to drop the front panel.? Not a major chore, just
one knob to remove (the band knob) and 6 side screws. With that now
out of the way, it was an easy job to determine if all the pins were
where they belonged.? The only snag was that the front panel, when
canted downwards, angles the PTO can upwards.? So you have to hold the
front panel perpendicular and steady with slight downward pressure to
fully seat the board.? Once all the pins were visually confirmed to be
seated, I remounted the front panel, reattached the regulators and all
the connectors, and fired the rig up.? Everything now seems to work!
It turns out the original DR-7 board was indeed defective as well
(possibly because it had been seated incorrectly).? And a visual
confirmation from topside indicates the chassis is, indeed, warped:
The screw hole is misaligned with the mounting hole in the board.
So, for archival purposes in case anyone else decides to search for
this problem: ?If the display if fixed on "51950", one possible cause
is that one or more DR-7 pins, possibly the VCO pins, are not
correctly seated.? The best solution is to drop the front panel and
confirm visually that the pins are fully seated.
Now it's time to get on the air!
? --Brian/WA3ITE
=================
Jim Shorney Fri, 30 Jul 2010 23:17:58 -0700
On Fri, 30 Jul 2010 20:40:52 -0500, Brian Koontz wrote: >Well, the TR-7 from hell is now a fully operational TR-7 from hell! > >Now it's time to get on the air! Congratulations, Brian! You have been assimilated into the collective. Resistance is futile. 73 -Jim
=================
? Garey Barrell k4oah@... via Sat, Jul 31, 2010, 8:34?AM to drakelist Brian Koontz wrote: > Some further investigation revealed that the chassis has warped over > the years, so the two 3-prong connectors on the VCO board were no > longer in a horizontal line.? So I was determined to make sure the > board was fully seated on all the connectors. > > > > So, for archival purposes in case anyone else decides to search for > this problem: ?If the display is fixed on "51950", one possible cause > is that one or more DR-7 pins, possibly the VCO pins, are not > correctly seated.? The best solution is to drop the front panel and > confirm visually that the pins are fully seated. >
Brian -
Congratulations!! ? It's always nice when one 'comes together'.
Just as an aside, someone suggested earlier (and correctly) that the
"51950" problem may indicate a loss of the 500 kHz reference signal.
You might find it interesting that the left-most three pin connector on
the VCO board is the 500 kHz reference signal!
Those pins on the bottom of the DR-7 are ALWAYS a problem, ya' just
can't see 'em!!
Your 'trials' have been an interesting 'trip' for others, thanks for
documenting it for us all.
73, Garey - K4OAH
Glen Allen, VA
Drake 2-B, 4-B, C-Line& ?TR-4/C Service Supplement CDs
<>
=================
? Search terms to make this post easier to find:? Drake TR-7 TR7 DR-7 DR7 display frozen locked stuck ? 51950?? 51,950?? 51 950?? 5195?
51950.0 ? 51,950.0 ? 51 950 0
??
|
Manual for the RR2 receiver
Hi Guys?
I'm working on restoring a Drake RR2 receiver , however I don't have any manual which makes kind of hard. ?I have seen that somebody offered CD or DVD with many Drake user and service manuals including the RR2 but got no reply from him. is there anyone in this group who can assist in either getting the CD/DVD or a service manual for the RR2?
Any assistance would be much appreciated.
?
73 de Jan /SM5MRQ
|
TNX for the info.? I'll have to look into this.? I had seen some other comments pertinent to these receivers and never found an answer...
FWIW, I only ever use the CD input of this receiver now to stream from either my computer or phone to play music.? It's amazing how we have come so far -- yet my older son has acquired a massive collection of vinyl and is a vinyl devote now.? Forty is the new twenty,,,
Steve Wedge, W1ES
Time flies like an arrow.? Fruit flies like a banana.
Sent with secure email.
On Friday, December 27th, 2024 at 1:32 PM, Mike Bryce via groups.io <prosolar@...> wrote:
from what I’ve read, the LCD uses LEDs to provide the lighting.
And, there are quite a few of them, like 64 leds…. the SW8 used a single bright LED with light pipes to the LCD.
I don’t believe, and I haven’t looked, that the R8 uses the glowing electro thingiee (yes, that is a correct technical term!)
I think you can replace the illuminator in this display. It’s been a while but I recall having done it once.
Gary
W0DVN On Dec 27, 2024, at 9:05?AM, Mike Bryce via < prosolar@...> wrote:
骋补苍驳…
I have a R8 sitting on my desk I got from a local ham. He went through it and replaced several handfuls of capacitors. The encoder was shot so he machined a new coupling to fit an off the shelf new encoder. Radio works great and looks good.
However!!
The LCD is so dim, it’s hard to see it.
Found the usual Google hits about cleaning contacts and so on. Nothing worked
is there a fix for the dim display? (other than a new LCD)
Mike, WB8VGE
SunLight Energy Systems
The Heathkit Shop
J e e p
o|||||||o?
A man with one clock knows what time it?is. A man with two clocks is never sure.
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One would assume that, since the DR7 gets the right answers on the low bands, that the DR7 is reading wha it sees on the high bands as well...
Gary
W0DVN
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On Dec 27, 2024, at 3:44?PM, Jim Shorney via groups.io <jimNU0C@...> wrote:
Of course that assumes that the counter is reading the signal correctly. Best to eliminate everything else before tearing in to the VCO board.
If extender boards are not available U502 checks can be made with the board on the bench by connecting a 10 Volt power source to pin 5/18.
On Fri, 27 Dec 2024 14:46:10 -0600
"Gary Follett via groups.io" <xntrick1948@...> wrote:
The math tells you that the VCO is operating at 100 MHz! No “N code” faults could produce that high frequency.
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73
-Jim
NU0C
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Of course that assumes that the counter is reading the signal correctly. Best to eliminate everything else before tearing in to the VCO board. If extender boards are not available U502 checks can be made with the board on the bench by connecting a 10 Volt power source to pin 5/18. On Fri, 27 Dec 2024 14:46:10 -0600 "Gary Follett via groups.io" <xntrick1948@...> wrote: The math tells you that the VCO is operating at 100 MHz! No “N code” faults could produce that high frequency. -- 73 -Jim NU0C
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Re: CW Filters and Passband Tuning?
If you happened to prefer a CW note that is, say, 400 Hz, it might be nice to center the PBT to optimize for a 400 Hz note. The same would be true if you preferred a 700 Hz tone.
In an old-fashioned receiver with tunable BFO, you did the same thing by placing the BFO to give you the tone you wanted when you were tuned to the proper frequency in the receiver.
This really only matters if you are using narrow CW filters...
Gary?
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On Dec 27, 2024, at 3:09?PM, Steve W1SRD via groups.io <w1srd@...> wrote:
What, if any, is the advantage of doing so?
Just curious.
73,
Steve
W1SRD
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Re: CW Filters and Passband Tuning?
What, if any, is the advantage of doing so?
Just curious.
73,
Steve
W1SRD
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Make the following check:
Then:
The math tells you that the VCO is operating at 100 MHz! No “N code” faults could produce that high frequency.
There can't be anything wrong with the circuit before R537 because all of that is shared with the low band VCO operation.
Next:
Just my humble observations…
Gary
W0DVN
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On Dec 27, 2024, at 1:16?PM, Jim Shorney via groups.io <jimNU0C@...> wrote:
N code info here:
/g/DRAKE-RADIO/files/TR-7/TR7%20PLL%20N%20Code%20and%20Digital%20Control%20Board%20Information
The Jumper Board logic chart is an early work by K4OAH (SK). It was hard to make sense of for me and I think contains some errors. I've been meaning to clean it up and verify but I forget about it every time I have a radio open.
On Fri, 27 Dec 2024 12:05:29 -0600
"Jim Shorney via groups.io" <jimNU0C@...> wrote:
There is an N code chart in the files section
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73
-Jim
NU0C
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Re: Drake L7 10m modification
Mine didn't have that so I made my own. Now I wished I had just ran another piece of coax.
Sent from my T-Mobile 5G Device
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-------- Original message -------- From: "Jim Shorney via groups.io" <jimNU0C@...> Date: 12/27/24 2:22 PM (GMT-05:00) Subject: Re: [DRAKE-RADIO] Drake L7 10m modification
The shorting trace would be obvious if you have the later circuit board. A single wide trace running from front to back with a hole for a wire at each end. The idea was to unsolder the coax center conductor at each end and move them to the shorting trace. On Fri, 27 Dec 2024 14:08:36 -0500 "Roger KW4EMF via groups.io" <rogerlhill@...> wrote: > Do you remember where the shorting trace is? -- 73 -Jim NU0C
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Re: Drake L7 10m modification
Here it is. A screw with a plan head no slot or anything. Just some knurl around the outside and a nut.
Sent from my T-Mobile 5G Device
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-------- Original message -------- From: "Evan via groups.io" <k9sqg@...> Date: 12/23/24 10:59 PM (GMT-05:00) Subject: Re: [DRAKE-RADIO] Drake L7 10m modification
Roger,
To my knowledge Drake used 3 different schemes to lockout 10/11 meters from the CB crowd. ?The one you have sounds like the one where there is a round head screw with/without a nut, something like a cap screw, possibly with an Allen head. ?The best way to remove it, I've found, is to do it from the bottom. ? However, ?do be careful and stuff some painters tape, or kleenex, ?or something "below" where that screw/nut might fall. ?That way you can capture it before it gets into some known/unknown location that could cause further damage upon power up. ?For me, I've found that needle nose pliers worked well with high illumination.
But let's hear what the experts say.
Best of luck.
73,
Evan, K9SQG
I've looked down in the band switch from the bottom and see a small nut. I can't really see the head. What is the best way to get at it? Top or bottom? What type of tools did you use? Going in from the bottom is extremely tight.?
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Jim Shorney
Jay W6CJ
