Re: DR7 fitting partial success.
In my experience the only area of the DR7 that is prone to shorting is the left rear corner where a set on Moolex pins reside. It's possible to push it down too far. I solved that problem with some flat stick-on rubber feet on the bottom of the board. 73 -Jim NU0C On Sun, 21 Mar 2021 10:53:55 -0700 "Mike Davidsohn G3ZCC" <mike@...> wrote: Hi Gary
Funnily enough I made a strip out of clear acrylic which I put on the shelf where the? bulb clips on.
Also put one over the lower level cover and cut out holes for the wires etc.
By bad foil do you mean a strip of printed circuit that is ground?
Will check those out too.
Thanks for the tips.
Kind Regards
Mike G3ZCC
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Re: DR7 fitting partial success.
More likely it is a broken trace than anything else. The display board is a nasty bugger to unsolder. The LEDs are a standard off the shelf pinout, you could replace them if bad. Not that I am discouraging you from sending DF4NW some money, he is a good guy. I bought the first blue display in the original LED size from him. Since I had already changed the ALC lamp to blue I had the first all blue TR7 in the world, a claim that has not been challenged to this day! 73 -Jim NU0C On Sun, 21 Mar 2021 10:49:07 -0700 "Mike Davidsohn G3ZCC" <mike@...> wrote: Hi Jim
Managed to repair one of the spare PTO's all fitted back and seems to be? working ok.
Not putting the front back as I am changing the bulbs to blue LED's.
Then to the DR7 will check through again, thanks for the tip on checking the segments, will do that tomorrow.
If those LED's have a problem I will check out DF4NW to see if I can get a replacement.
Hoping it's just a solder joint.
Kind Regards
Mike
G3ZCC
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Re: DR7 fitting partial success.
Thanks Joe
By multiplexed do you mean the bank of resistors (I think 100k) going between the KHz segment and the Mhz?
Will look at those as well.
?
Kind Regards?
Mike
G3ZCC
|
My Murch is green. But it's not a "B" model. Someone had butchered it with cheapo verniers that were worn out. I actually found a pair of period correct knobs molded in green plastic to restore it with. It looks ... interesting. :) And I really don't care that it doesn't match the rigs. It should be noted that early designs did not have a bypass switch, which is not a big deal for a single band use antenna that needs it. 73 -Jim NU0C On Sun, 21 Mar 2021 10:22:00 -0700 "VE7PS" <ve7ps@...> wrote: Someone mentioned the Murch tuner - it's black - wouldn't look bad at
all next to a 4-line.
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Re: DR7 fitting partial success.
Hi Gary
Funnily enough I made a strip out of clear acrylic which I put on the shelf where the? bulb clips on.
Also put one over the lower level cover and cut out holes for the wires etc.
By bad foil do you mean a strip of printed circuit that is ground?
Will check those out too.
Thanks for the tips.
Kind Regards
Mike G3ZCC?
|
I ment the MN-4C, I don't know why I said the MN-2000C......
I've looked at the Murch tuners as well.
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Re: DR7 fitting partial success.
Hi Jim
Managed to repair one of the spare PTO's all fitted back and seems to be? working ok.
Not putting the front back as I am changing the bulbs to blue LED's.
Then to the DR7 will check through again, thanks for the tip on checking the segments, will do that tomorrow.
If those LED's have a problem I will check out DF4NW to see if I can get a replacement.
Hoping it's just a solder joint.
?
Kind Regards
Mike
G3ZCC
|
I was just thinking the same thing. I have a Murch sitting atop my MN2700. And a second homebrew knockoff awaiting cleanup. Spent less money than a night on the town for both combined. 73 -Jim NU0C On Sun, 21 Mar 2021 16:45:41 +0000 "Dick" <w1ksz@...> wrote: Look for a Mutch UT-2000B (not the A). They go for short money
and will load up the proverbial bedspring.
73, Dick, W1KSZ
________________________________
From: [email protected] <[email protected]> on behalf of Billy Pickering KO4INE <pickeringw@...>
Sent: Sunday, March 21, 2021 9:16 AM
To: [email protected] <[email protected]>
Subject: Re: [DRAKE-RADIO] MN2000
We have a huge hamfest coming up this next Saturday in Sevierville that I'm going to keep an eye out there and see what I can find. Thanks everyone.
|
Billy:
An MN-2000C?? Never heard of this one and I thought I knew of all
the Drakes including the commercial marine reserve gear.? There is
an MN-4C for sure (have one) which looks like an MN-7, but matches
the 4-line, though not as well as the MN-4/MN-2000.
Someone mentioned the Murch tuner - it's black - wouldn't look bad
at all next to a 4-line.
73
Peter
VE7PS
On 2021-03-21 9:14 a.m., Billy
Pickering KO4INE wrote:
toggle quoted message
Show quoted text
I've been looking at the MN-2700 but like said, it doesn't really
match, would love to find an MN-2000C which is an MN-2700 in the 4
line colors which are a little harder to find. I do actually have
a 550ish ft. horizontal loop up already that I'm currently using a
Yaesu FT-1000MP with but it has a built in tuner. I want to use my
Drake, but don't want to mess anything up with it.
|
Re: DR7 fitting partial success.
I have 4 TR7As, one of them I purchased new and none of them have
anything glued to the top of the? PTO can. I also currently have 3
TR7s with serial numbers in the 9000s and none of them have any thing
glued to the PTO. On the DR7 the LEDs are multiplexed, all of the
segments of each digit are in parallel with the segments of all of the
other digits, all the A segments are connected to all of the other A
segments etc. If a single digit segment is missing then it's either the
connection or a bad LED itself.
73, Joe Pyles KC9LAD
At 12:00 PM 3/21/2021, you wrote:
toggle quoted message
Show quoted text
Did you check that there is an
insulting strip loin top of the PTO mechanism? There is a very close fit
between the bottom of the DR7 solder? and the grounded metal below
the DR7 just below the display elements. This often results in dead
segments.
Drake,? in later radios, glued a grey piece of high voltage
cardboard on top the PTO assembly. Your radio looks like a pretty early
one so may not have this.
Also, the notion suggested by another, a bad foil, makes sense because
the same segments are dead on both the MHz displays.
Gary
W0DVN
On Mar 21, 2021, at 7:19 AM,
Steve Wedge, W1ES/4 via
<
w1es@...> wrote:
The second digit is missing two segments. It looks like a display or
driver issue to me (assuming the etches and soldering are okay).
I can?�?t remember if the display drivers are open collector or not.
Check the output of the display driver for each digit.
73,
Steve Wedge, W1ES/4
Time flies like an arrow.? Fruit flies like a banana.
Sent from ProtonMail Mobile
On Sun, Mar 21, 2021 at 06:34, Mike Davidsohn G3ZCC
<mike@...>
wrote:
Hi Everyone, hope you are safe and well.
I have fitted the rebuilt DR7 and the up/down and jumper works just
fine.
The first two digits seen to be missing the same part of the display
which is a lovely blue colour.
I have also knocked the PTO calibration so I will have to fix
that.
The fact that the first two digits are missing the same segments leads me
to believe that it is not the display itself.
I have attached a picture of the TR7 on 28.888
Any thoughts
Kind Regards
Mike
G3ZCC
|
Look for a Mutch UT-2000B (not the A). They go for short money
and will load up the proverbial bedspring.
73, Dick, W1KSZ
toggle quoted message
Show quoted text
We have a huge hamfest coming up this next Saturday in Sevierville that I'm going to keep an eye out there and see what I can find. Thanks everyone.
|
We have a huge hamfest coming up this next Saturday in Sevierville that I'm going to keep an eye out there and see what I can find. Thanks everyone.
|
Re: DR7 fitting partial success.
Interesting. I don't recall having seen this. Fish paper maybe? 73 -Jim NU0C On Sun, 21 Mar 2021 11:00:19 -0500 "Gary Follett" <xntrick1948@...> wrote: Drake, in later radios, glued a grey piece of high voltage cardboard on top the PTO assembly. Your radio looks like a pretty early one so may not have this.
|
I've been looking at the MN-2700 but like said, it doesn't really match, would love to find an MN-2000C which is an MN-2700 in the 4 line colors which are a little harder to find. I do actually have a 550ish ft. horizontal loop up already that I'm currently using a Yaesu FT-1000MP with but it has a built in tuner. I want to use my Drake, but don't want to mess anything up with it.
|
I agree ?with Peter. ?In fact, I use my MN-2000 for 40 meter operation but use my MN-2700 for all other ?bands due to ?the wide matching range. ?Once you find the sweet spot for each band, logging the settings (including the extra capacity lever switch controls) makes tune up very easy.
73,
Evan, K9SQG
-----Original Message-----
From: VE7PS <ve7ps@...>
To: [email protected]
Sent: Sun, Mar 21, 2021 11:34 am
Subject: Re: [DRAKE-RADIO] MN2000
Billy:
Indeed, the MN-2700 might be a better choice for 160m than trying to
convert an MN-2000.? 160M coverage is already built into the 2700.
It won't quite match your 4-line for sure.....but there's your
excuse to add a 7-line to the shack, if not there now!
73
Peter
VE7PS
On 2021-03-21 8:12 a.m., Mike Davidsohn
G3ZCC wrote:
Hi Billy
I would think it near impossible to add 160 to the MN 2000.
It looks like a high Q circuit and I read somewhere that it
performs best when using antennas of near resonance and is
tetchy on 80m.
As has been said, you would have to add inductance, probably to
the 80m section of the coil and also parallel capacitance as a
minimum.
Look at the tuning capacitors in the schematic, way too small
for Topband.
You would have to fit some kind of switch, not a good idea imo.
Simplest thing is to to put up a Topband quarter wave antenna
and use the MN 2000 in direct mode.
Better still make a separate ATU for Topband and paint the case
the same colour as the MN 2000.
How about one of the MFJ Autotuners?
Back in the 60's when I got licensed, we were limited to ten
watts , I used a 132 ft long wire with an ATU, in those days
built on wood.
Topband can be very forgiving, I have worked over 200 countries
now and also a member of the Topband Hall of Fame.? ??
It is my favourite band my first DX was Stew W1BB and Ralph
W1HGT, that really whetted my appetite.
Good luck with it Billy , hope you sort something out.
?Kind Regards
Mike
G3ZCC
|
Joe – W7RKN ? ? Billy:
Indeed, the MN-2700 might be a better choice for 160m than trying to convert an MN-2000.? 160M coverage is already built into the 2700. Better looking too!
It won't quite match your 4-line for sure.....but there's your excuse to add a 7-line to the shack, if not there now!
|
Re: DR7 fitting partial success.
Did you check that there is an insulting strip loin top of the PTO mechanism? There is a very close fit between the bottom of the DR7 solder ?and the grounded metal below the DR7 just below the display elements. This often results in dead segments.
Drake, ?in later radios, glued a grey piece of high voltage cardboard on top the PTO assembly. Your radio looks like a pretty early one so may not have this.
Also, the notion suggested by another, a bad foil, makes sense because the same segments are dead on both the MHz displays.
Gary
toggle quoted message
Show quoted text
On Mar 21, 2021, at 7:19 AM, Steve Wedge, W1ES/4 via < w1es@...> wrote:
The second digit is missing two segments. It looks like a display or driver issue to me (assuming the etches and soldering are okay).?
I can’t remember if the display drivers are open collector or not. Check the output of the display driver for each digit.?
73,
Steve Wedge, W1ES/4
Time flies like an arrow.? Fruit flies like a banana.
Sent from ProtonMail Mobile
On Sun, Mar 21, 2021 at 06:34, Mike Davidsohn G3ZCC <mike@...> wrote:Hi Everyone, hope you are safe and well. I have fitted the rebuilt DR7 and the up/down and jumper works just fine. The first two digits seen to be missing the same part of the display which is a lovely blue colour. I have also knocked the PTO calibration so I will have to fix that. The fact that the first two digits are missing the same segments leads me to believe that it is not the display itself. I have attached a picture of the TR7 on 28.888 Any thoughts Kind Regards Mike G3ZCC
|
Billy:
Indeed, the MN-2700 might be a better choice for 160m than trying to
convert an MN-2000.? 160M coverage is already built into the 2700.
It won't quite match your 4-line for sure.....but there's your
excuse to add a 7-line to the shack, if not there now!
73
Peter
VE7PS
On 2021-03-21 8:12 a.m., Mike Davidsohn
G3ZCC wrote:
toggle quoted message
Show quoted text
Hi Billy
I would think it near impossible to add 160 to the MN 2000.
It looks like a high Q circuit and I read somewhere that it
performs best when using antennas of near resonance and is
tetchy on 80m.
As has been said, you would have to add inductance, probably to
the 80m section of the coil and also parallel capacitance as a
minimum.
Look at the tuning capacitors in the schematic, way too small
for Topband.
You would have to fit some kind of switch, not a good idea imo.
Simplest thing is to to put up a Topband quarter wave antenna
and use the MN 2000 in direct mode.
Better still make a separate ATU for Topband and paint the case
the same colour as the MN 2000.
How about one of the MFJ Autotuners?
Back in the 60's when I got licensed, we were limited to ten
watts , I used a 132 ft long wire with an ATU, in those days
built on wood.
Topband can be very forgiving, I have worked over 200 countries
now and also a member of the Topband Hall of Fame.? ??
It is my favourite band my first DX was Stew W1BB and Ralph
W1HGT, that really whetted my appetite.
Good luck with it Billy , hope you sort something out.
?Kind Regards
Mike
G3ZCC
|
Hi Billy
I would think it near impossible to add 160 to the MN 2000.
It looks like a high Q circuit and I read somewhere that it performs best when using antennas of near resonance and is tetchy on 80m.
As has been said, you would have to add inductance, probably to the 80m section of the coil and also parallel capacitance as a minimum.
Look at the tuning capacitors in the schematic, way too small for Topband.
You would have to fit some kind of switch, not a good idea imo.
Simplest thing is to to put up a Topband quarter wave antenna and use the MN 2000 in direct mode.
Better still make a separate ATU for Topband and paint the case the same colour as the MN 2000.
How about one of the MFJ Autotuners?
Back in the 60's when I got licensed, we were limited to ten watts , I used a 132 ft long wire with an ATU, in those days built on wood.
Topband can be very forgiving, I have worked over 200 countries now and also a member of the Topband Hall of Fame.? ??
It is my favourite band my first DX was Stew W1BB and Ralph W1HGT, that really whetted my appetite.
Good luck with it Billy , hope you sort something out.
?Kind Regards
Mike
G3ZCC
|
Re: DR7 fitting partial success.
It looks like you have an aftermarket LED board from DF4NW. Nice! However that suggests that someone botched the install and gave up on it. The display is strobed. One set of segment drivers drives all the digits, and the data is clocked through to each digit fast enough that you see no flicker. Since most of the digits show all segments that means your segment drivers are good. That leaves you with the segment driver connections to the bad digits and the digit LEDs themselves. You can check the LED segments individually using an Ohmmeter as you would any diode. These are common anode displays, the pinout can be found online or you can trace it out from the schematic. You can tilt the front panel down for easy PTO access by following the procedure in section 2-18 of the service manual. Be careful with step 5, go slowly and watch for any band switch sections that may want to stick to the shaft. Check soldering in the PTO. 73 -Jim NU0C On Sun, 21 Mar 2021 07:25:15 -0700 "Mike Davidsohn G3ZCC" <mike@...> wrote: Thanks Steve.
Both digit one and two are missing the two segments I think..
You may be right about the soldering, it was a mess so I re did it .
Will check again? and also look at the drivers.
I am wondering if it is something to do with the connections on the 100k? resistors that go between the? four and two displays.
Have had to pull the board out as I have a PTO issue to sort first.
Both my spares are not working so have to fix the one in the TR7.
The lamp holder has damaged the cog on the adjuster so trying to solve this before moving back to the board.
Kind Regards
Mike
G3ZCC
|
Jim Shorney
Mike Davidsohn G3ZCC
Dick
