Hello All,
My "ebay-INOP" TR-7 is mostly working. The problems were mostly in the connectors. The remaining problem is
occasional loss of lock. It happens at random times, a few times a day. A quick poke on the "RCV FIX" button fixes it. An appropriately named button!
I still haven't cleaned the connectors on the cards under the shield panel that is under the DR-7 display board. Maybe that will fix it up.
Also planning to do a full alignment, starting with the 10V - which I suspect is now 9V. At least, that's what's reaching the fan, from a pair of homebrew-added wires departing into the guts of the radio. Preparatory
to that, I discovered I needed a frequency counter. And it had to be reasonably sensitive. So I ordered - and
received about an hour ago - an HP 5385A. Supposed to be good down to 15mV RMS. Not wanting to pull out serious
instruments to check it out, I grabbed my Millen grid dip oscillator off the shelf, wound a clip lead around the coil and patched it up to a BNC. Yup, it's plenty sensitive. It measured the RF on my clip lead with the loop about an inch away from the GDO coil. And the Millen is well calibrated....for a GDO.
Another item that the manual says I need to do an alignment is a VTVM. Don't have one of those. Well, I'm
pretty sure there's an HP410B hiding in the junk somewhere, but darned if I can find it. Pretty sure I can
manage with an oscilloscope. But just for yuks, I ordered a Heathkit V7B on Ebay.
I replaced the trim pots on the power supply board with 10-turn units. The original pots had their pins in a triangular pattern; the 10-turn ones in my junkbox had the three pins all in a row. No problem - bend these that way a bit, and bend the middle one the other way, and they plug right in, tilted up a bit for easy tweaking. But the pots are sort of in mid-air hanging off their pins. And when you fuss with it - plugging the board in & out - they get bent out of position. Then you put them back, but you don't get to do that too many times before the pin breaks off - especially the leftmost pot. Reinforcement? I cut a strip of phenolic perfboard to a size just right to lay across the sides of
all the pots. Applied accelerant to the pots, cyanoacrylate cement to the perfboard and glued it to the pots. Now they're still hanging in midair, but in order to push one out of line, you have to push all of them, and it's a lot stronger.
I obtained a 450Hz CW filter from Noble Radio and installed it. Now we have viable CW! I decided to also get a 2.7 kHz SSB filter for better intelligibility. Also got a patch card and extender cards.
I'm planning to build an AUX7 card. There is ample information on the Web and in the TR7 service manual to do that. It will get me full WARC band coverage without cutting the "transmit anywhere" trace. Ebay yielded up
three baggies of 4-pin female Molex connectors ( P/N 09-62-3041 ). These are higher quality connectors than what Drake used - they have selective gold plating on the connection. More than I need, but I always get spares.
Also got some Augat machine sockets to connect & make the individual band modules. Plan to wire it up with 30gauge Kynar "wire wrap" wire, of which I have a good supply.
I did the mod to control the SSB power with the carrier level pot. Seems to work. I still can't use it with
my linear though; Need to figure a way to get band data out of the transceiver, OR - modify the linear to have its own bandswitch. I have resisted doing that because the LDMOS device is expensive and would be a genuine
PITA to replace. But it is protected; the linear has two tandem matches, one before its LPF, the other after.
- Jerry, KF6VB
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I had found that R50 (the 15M RF GAIN pot) in 2-B No. 2 read 26M.? I checked the pot in 2-B No 1 (the parts receiver) and it was 20M.? No. 3 also reads 20M and adjusts easily, to I decided to pull the pot from the parts rig and install it into No.2.
NOTHING WORKED RIGHT.
Traced wires and triple-checked all connections.? The RF GAIN control was doing nothing.
Long story short (for I'm being called to supper!), the wiper of the pot from the parts rig had a high resistance short to the case (and thus, to ground).
I cleared it with contact cleaner and it's okay now.? Meanwhile, I put the original pot back in with a 22M resistor in parallel with the terminals.? Receiver No. 2 is now aligned and ready for its bath tomorrow.
73,
Steve Wedge, W1ES/4
Time flies like an arrow.? Fruit flies like a banana.
Sent with secure email.
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Re: TUning on the lower bands with the MN-2000?
The Reactive is the large knob on the Left and the Restive is the large knob on the Right.? The band switch is in the middle of those knobs. So after setting to the correct band which would be middle knob counter clockwise for 80 meters start with the right knob for a dip and the left knob for a slight rise and repeat.
I am not real sure as I do not have the low power version to check now but the large knobs may be reversed on it.??
Ralph ku4pt
On Monday, May 8, 2023 at 05:06:28 PM EDT, Justin Mann via groups.io <w9fyi@...> wrote:
I¡¯m assuming the resistive tuning knob is the large knob on the left, and the reactive tuning knob is on the right, with the band switch in the middle? ?
On May 8, 2023, at 3:58 PM, Ralph Mowery via groups.io <ku4pt@...> wrote:
You are at a big disadvantage trying to tune this tuner..? Here is the way it needs to be done.
After setting the band switch tune the Resistive Tuning for a SWR dip. Then turn the Reactive Tuning to the Right a slight amount.? The SWR will increase.? Then tune the Restive tuning for a dip in the SWR.? If lower then repeat the process.? If higher , tune the Reactive tuning to the left and then tune the Resistive tuning for the lowest SWR.? Repeat the process several times if needed.
This seems to be similar to the way a tube transmitter tunes up.
The low power version tunes the same way.
Very different than most tuners I have used.
Ralph ku4pt
On Monday, May 8, 2023 at 04:15:49 PM EDT, Justin Mann via groups.io <w9fyi@...> wrote:
HI Ralph, I don¡¯t have an accessible manual for some one who is blind to use that tuner, so I¡¯ve been tuning for maximum noise, and using my audible tuning aid, a TW-1 made by LDG to try and get the SWR down. ?Can you give me some kind of a synopasys on what I should do? ?The pdfs are scanned, so they are difficult for me to get text extracted from the dockuments.
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I have 4 pieces of index card stock painted with Rustoleum "Satin Black, 7777" cut to fit each upper surface of the final cage.? Installed a computer fan on the back panel, exhausting out.? This pulls air up through the perforated metal bottom of the T4X-C final compartment, past the tube pin seals and around both tubes then out the back of the radio.?
It works wonderfully!? Have had the same set of finals in the radio for 15 years + and it still puts 140W to the antenna.
The T4X-C fan switches on with the radio.? On the TR4-CW, it turns on manually.? With the extra final and higher output, cooling the pin seals and envelope with everything off, including the filaments is a feature noted on every tube (and some solid-state) AM or FM broadcast transmitter I've ever come across.? Plus, when in the USCGR, we must have had 70 Collins HF-80's in various COMMSTA's and they were worked extremely hard, making several 3-1/2 hour-long WEFAX transmissions.
Chuck Rippel K8HU
-- Chuck Rippel, K8HU
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Re: TUning on the lower bands with the MN-2000?
I¡¯m assuming the resistive tuning knob is the large knob on the left, and the reactive tuning knob is on the right, with the band switch in the middle? ?
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On May 8, 2023, at 3:58 PM, Ralph Mowery via groups.io <ku4pt@...> wrote:
You are at a big disadvantage trying to tune this tuner..? Here is the way it needs to be done.
After setting the band switch tune the Resistive Tuning for a SWR dip. Then turn the Reactive Tuning to the Right a slight amount.? The SWR will increase.? Then tune the Restive tuning for a dip in the SWR.? If lower then repeat the process.? If higher , tune the Reactive tuning to the left and then tune the Resistive tuning for the lowest SWR.? Repeat the process several times if needed.
This seems to be similar to the way a tube transmitter tunes up.
The low power version tunes the same way.
Very different than most tuners I have used.
Ralph ku4pt
On Monday, May 8, 2023 at 04:15:49 PM EDT, Justin Mann via groups.io <w9fyi@...> wrote:
HI Ralph, I don¡¯t have an accessible manual for some one who is blind to use that tuner, so I¡¯ve been tuning for maximum noise, and using my audible tuning aid, a TW-1 made by LDG to try and get the SWR down. ?Can you give me some kind of a synopasys on what I should do? ?The pdfs are scanned, so they are difficult for me to get text extracted from the dockuments.
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Re: TUning on the lower bands with the MN-2000?
You are at a big disadvantage trying to tune this tuner..? Here is the way it needs to be done.
After setting the band switch tune the Resistive Tuning for a SWR dip. Then turn the Reactive Tuning to the Right a slight amount.? The SWR will increase.? Then tune the Restive tuning for a dip in the SWR.? If lower then repeat the process.? If higher , tune the Reactive tuning to the left and then tune the Resistive tuning for the lowest SWR.? Repeat the process several times if needed.
This seems to be similar to the way a tube transmitter tunes up.
The low power version tunes the same way.
Very different than most tuners I have used.
Ralph ku4pt
On Monday, May 8, 2023 at 04:15:49 PM EDT, Justin Mann via groups.io <w9fyi@...> wrote:
HI Ralph, I don¡¯t have an accessible manual for some one who is blind to use that tuner, so I¡¯ve been tuning for maximum noise, and using my audible tuning aid, a TW-1 made by LDG to try and get the SWR down. ?Can you give me some kind of a synopasys on what I should do? ?The pdfs are scanned, so they are difficult for me to get text extracted from the dockuments.
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So I have picked up a Turner Plus Three microphone. It looks like the one they made for Drake with the 7075 except it is amplified. I remember seeing somewhere that all that can by bypassed and use as a non-amplified microphone. I'm wanting to put it with my TR7 or possibly change out the plug to use with my T-4XC and TR-4C. Does anyone know about doing this?
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Re: FS - TR-7 parts radios
I am interested What do you think shipping would be?? Perhaps if I knew the dims and weight I could send a shipping label?
Marty KL7AM
From: "George Maier via groups.io" <georgew1lsb@...> To: "DRAKE-RADIO" < [email protected]> Sent: Monday, May 8, 2023 12:37:34 PM Subject: [DRAKE-RADIO] FS - TR-7 parts radios
I have two TR-7 parts radios for sale. S/N 2794 is complete but inoperative; some previous owner unsuccessfully attempted repairs. It is missing a few knobs and also needs a serious cleaning.? S/N 8939 is quite clean but missing the following boards: digital display, NB bypass or NB, PBT, PA module. Photos are available.? Asking $150 each or both for $250 plus shipping. Thanks for looking & 73, George - W1LSB
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I have two TR-7 parts radios for sale. S/N 2794 is complete but inoperative; some previous owner unsuccessfully attempted repairs. It is missing a few knobs and also needs a serious cleaning.? S/N 8939 is quite clean but missing the following boards: digital display, NB bypass or NB, PBT, PA module. Photos are available.? Asking $150 each or both for $250 plus shipping. Thanks for looking & 73, George - W1LSB
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Re: TUning on the lower bands with the MN-2000?
HI Ralph, I don¡¯t have an accessible manual for some one who is blind to use that tuner, so I¡¯ve been tuning for maximum noise, and using my audible tuning aid, a TW-1 made by LDG to try and get the SWR down. ?Can you give me some kind of a synopasys on what I should do? ?The pdfs are scanned, so they are difficult for me to get text extracted from the dockuments.
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On May 8, 2023, at 3:13 PM, Ralph Mowery via groups.io <ku4pt@...> wrote:
Are you following the Drake tuning instructions ?? That tuner tunes up much different than most of the others that use a PI type network.
First time I tried to tune one I could not get it to match anything, but following instructions it works fine evn with my L4B amp on there is very little reflected power on my OCF or 80 meter dipole.
Ralph ku4pt
On Monday, May 8, 2023 at 04:06:56 PM EDT, Justin Mann via groups.io <w9fyi@...> wrote:
folks,
I¡¯ve been trying to use my MN-2000 with my off-center fed dipole, and my Parr end-fed antenna on the lower bands to tune up on 80 meters, and I notice that it¡¯s a challenge to get a 1:1 match.? If I use my heath kit 2060-A everything tunes up just fine.? Is there something I might do to make this tuner work better?? It seems as though it¡¯s in grate shape, so I¡¯m a bit puzzled.
Thanks,
Justin-ai5os
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Re: TUning on the lower bands with the MN-2000?
Are you following the Drake tuning instructions ?? That tuner tunes up much different than most of the others that use a PI type network.
First time I tried to tune one I could not get it to match anything, but following instructions it works fine evn with my L4B amp on there is very little reflected power on my OCF or 80 meter dipole.
Ralph ku4pt
On Monday, May 8, 2023 at 04:06:56 PM EDT, Justin Mann via groups.io <w9fyi@...> wrote:
folks,
I¡¯ve been trying to use my MN-2000 with my off-center fed dipole, and my Parr end-fed antenna on the lower bands to tune up on 80 meters, and I notice that it¡¯s a challenge to get a 1:1 match.? If I use my heath kit 2060-A everything tunes up just fine.? Is there something I might do to make this tuner work better?? It seems as though it¡¯s in grate shape, so I¡¯m a bit puzzled.
Thanks,
Justin-ai5os
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TUning on the lower bands with the MN-2000?
folks,
I¡¯ve been trying to use my MN-2000 with my off-center fed dipole, and my Parr end-fed antenna on the lower bands to tune up on 80 meters, and I notice that it¡¯s a challenge to get a 1:1 match. If I use my heath kit 2060-A everything tunes up just fine. Is there something I might do to make this tuner work better? It seems as though it¡¯s in grate shape, so I¡¯m a bit puzzled.
Thanks,
Justin-ai5os
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Re: Remove case from MN 2000
All put back together and tested on my TR7 station without and with an amplifier. Seems to work perfect and meter tracks with my WH7 and MN 2700 fine. Seems like I got it at a good price and it works. That is fine.
73? Bob K6OXN
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Re: Contacting K4OAH For Cd's
I just shake my head......
From this site:
And open a case with PayPal.
Still shaking my head in wonder...
Jim W7RY
On 5/8/2023 1:12 PM, Joe Wolfe wrote:
2 Months
ago, I sent 25 dollars, via PayPal, ?to K4OAH¡¯s sales site
for a set of ¡®C¡¯ cd¡¯s. via download. I have heard nothing?
from whomever administers to sales.
?
Can anyone
here direct me to a good contact number or site to get this
rectified?
?
Thanks..
?
Joe ¨C W7RKN
--
Thanks and 73, Jim W7RY
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Contacting K4OAH For Cd's
2 Months ago, I sent 25 dollars, via PayPal, ?to K4OAH¡¯s sales site for a set of ¡®C¡¯ cd¡¯s. via download. I have heard nothing? from whomever administers to sales. ? Can anyone here direct me to a good contact number or site to get this rectified? ? Thanks.. ? Joe ¨C W7RKN
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Notice: I have decided to turn over my supply of TR7 connectors, cable and crimp tool to Steve WA4F. Except for one local Colorado ham who may come by my house this week, Steve will supply these items at little or no charge. There would likely be a modest fee to cover shipping or USPS mailing cost.
I will now start a major downsizing of Drake R-4C "parts radios". Local pickup at this time only. Shipping costs for an R-4C has skyrocketed. If a ham would like to pickup these "parts radios" up and part them out, this would be great.
Rob Sherwood, NC0B
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-----Original Message----- From: Rob Sherwood. Sent: Friday, May 05, 2023 2:15 PM To: [email protected]Subject: RE: [DRAKE-RADIO] TR7 Connectors If anyone needs some of those tiny crimp-on RG-174 size connectors I have lots of them. Had to purchase 1000 of each for interfacing my 7-SP speech processor to the TR-7. (Product long out of production.) There is the chassis connector (called the lunar lander in some Drake documentation!), the coax tip female connector, and the coax crimp-on connector. I have the crimp-on tool, but I don't know how well a generic crimp tool would work. Rob, NC0B -----Original Message----- From: [email protected] [mailto: [email protected]] On Behalf Of Steve Wedge, W1ES/4 via groups.io Sent: Friday, May 05, 2023 2:07 PM To: [email protected]Subject: Re: [DRAKE-RADIO] TR7 Connectors I remember seeing them used on the clock boards for DECSystem 10 and 20. Million-dollar systems. The reasoning behind choosing them are the very small space requirements and the fact that these connectors were not designed to be disconnected/connected multiple times. 73, Steve Wedge, W1ES/4 Time flies like an arrow.? Fruit flies like a banana. Sent with Proton Mail secure email. ------- Original Message ------- On Friday, May 5th, 2023 at 3:57 PM, Gary Follett <xntrick1948@...> wrote: BTW: Even the ¡°great¡± Collins Radio Company used these junk connectors all over the very expensive KWM-380. All TenTec radios up through the Omni V, same deal.
Gary
W0DVN
On May 5, 2023, at 2:54 PM, sohosources kirk@... wrote:
Considering all of the innovations that went into the TR-series, I too have always wondered why they used those weird, probably failure-prone coax connectors... :)
--Kirk, NT0Z
Those connectors are REALLY chintzy. I think the center pin is just the center conductor of the coax itself. I wonder if one could upgrade them to SMA connectors?
- Jerry, KF6VB
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Re: 2-B AGC voltage ¡ª possibly resolved
Thanks, Johni was going to do the calculations but it¡¯s not easy when in the passenger seat of a moving car. :-)
I figure that it took 61 years for the part to drift that far, so any corrections should outlast me.?
73,
Steve Wedge, W1ES/4
Time flies like an arrow. Fruit flies like a banana.
Sent from Proton Mail for iOS
On Mon, May 8, 2023 at 10:44, John Magliacane via groups.io < kd2bd@...> wrote:
On Sunday, May 7, 2023, 09:17:51 PM EDT, Steve Wedge, W1ES/4 via groups.io <w1es@...> wrote:
> I checked into the Sunday net today and Jeff, WA8SAJ, suggested that I check the RF GAIN pot. This is a 15M (!) pot and is not very easy to find, these days.
>
> I measured the pot across the entire part, since there¡¯s one end that isn¡¯t connected to anything.
>
> The pot measured 26M ohms.
If you can shunt your pot (fixed end to fixed end) with a made-up series combination of fixed resistors that yields about 35 megohms, you'lll be able to bring your 26 meg pot down to 15 megs.
73 de John, KD2BD
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Re: 2-B AGC voltage ¡ª possibly resolved
On Sunday, May 7, 2023, 09:17:51 PM EDT, Steve Wedge, W1ES/4 via groups.io <w1es@...> wrote:
> I checked into the Sunday net today and Jeff, WA8SAJ, suggested that I check the RF GAIN pot. This is a 15M (!) pot and is not very easy to find, these days.
>
> I measured the pot across the entire part, since there¡¯s one end that isn¡¯t connected to anything.
>
> The pot measured 26M ohms.
If you can shunt your pot (fixed end to fixed end) with a made-up series combination of fixed resistors that yields about 35 megohms, you'lll be able to bring your 26 meg pot down to 15 megs.
73 de John, KD2BD
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Re: Remove case from MN 2000
Bob:
Glad you got it out.? The MN-2000 and MN-4 can be a bear to remove from the cabinet.? Same with the C-4 console, especially if someone has replaced the inner cover screws with round head screws, or screws with damaged?heads.
Per WB4HFN's serial number database the MN-2000 was made from at least 1968 to 1978 with over 10,000 units produced.? They are quite common to find at fleamarkets here in Canada, usually for about $200-$250.
In Version 2, Drake made a slight change to the wattmeter calibration circuit.? In version?1, it looks like you had to calibrate the 200w scale first, then the 2000w scale, in that order.? In version 2, the calibrations of the two scales should be independent.? A simple wiring change would correct version 1 if you wanted to do that.??I have not checked?for other changes between the two versions.
73 Peter VE7PS
On Sun, May 7, 2023 at 9:10?PM K6OXN Bob < bobk6oxn@...> wrote: And yes it is built like a sherman tank
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It could, if you use a large piece.?
Steve Wedge, W1ES/4
Time flies like an arrow. Fruit flies like a banana.
Sent from Proton Mail for iOS
On Mon, May 8, 2023 at 09:23, Jim Linsenbardt < jim.linsenbardt@...> wrote: Hi Gary,
Does the paper on top of the finals affect their cooling?
73's
Jim
KD0WF
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Chuck Rippel - K8HU and ex - NMN
Rob Sherwood