In light of the discussion regarding the shipment of transmitting tubes vs the apes at the shipping companies, I have a pair of Eimac 3-500Z's available for pickup only in the Greensboro/Raleigh-Durham area.? I had these in my L7 recently and wanted to make sure that they were good before offering them.? I had no trouble getting over a kW out of them in my L7.
I don't need two sets of tubes, so I'm offering these at $250 for the pair.? I will meet you within 50 miles or so of my home QTH in Graham, NC.
73,
Steve Wedge, W1ES/4
Time flies like an arrow.? Fruit flies like a banana.
Sent with secure email.
|
Re: Another TR7 Journey begins
Hi Jim,
I really appreciate your help.? I was loking at the wrong PDF and the ALC board pic was so blurry I didn't see the label.? I was able to get the voltage down to around 0.5 VDC on a multimeter.? I don't have a VTVM but I'm pretty sure these new meters work OK for this.? The AC control on the ALC board is still extremely touchy and the Forward/Reflected power adjustments do nothing.? In both Forward and Reflected as selected by the pushbotton the panel the meter actually goes below zero.? I was able to get the S-meter set so I know the meter is OK.??
So as far as I can tell the ALC is still not working properly.? Still think that control could be the problem.? I do have a can of the old Radio Shack control/contact cleaner and lubricant - wopuld that be OK to use on that control?
73, Bill NZ0T
|
Re: Another TR7 Journey begins
Look for the High Pass Filter Module schematic, Fig. 2-28. There is a list of illustrations in the front of the SM, page V. Page 2-80 is correct for the 1978 manual that I am looking at. I am aware that different revision manuals may have some slight variations in page numbering. I have no intent of researching that. You have all the information you need to find it. 73, -Jim NU0C On Mon, 12 Feb 2024 09:53:58 -0800 "Dale Parfitt" <PARINC1@...> wrote: Hi Jim,
Page 2-80 is a blank "Notes" page in my original Service manual notebook.
Dale W4OP
|
Re: Another TR7 Journey begins
Hi Jim,
Page 2-80 is a blank "Notes" page in my original Service manual notebook.
Dale W4OP
|
Re: All bent out of shape (3-500z)
The plate structures in all of these type tubes are fairly massive.? It was probably a side acceleration that actually moved it but I'm thinking that the plate "pin" might not be bent.? The plate structure appears to be tightly crimped and/or spot" welded to the pin
If the side acceleration was sufficient to break that spot weld or cause the crimped connection to loosen,? you could probably give it a little acceleration in the other direction to center the plate structure, but it would be forever "loose"?? (hence the "noise)
If it was enough acceleration to actually "bend" the pin, you could probably (carefully) "accelerate" it in the other direction to straighten it.?
It would be worth a try since the tube is now a science project anyway! Not much to lose here. (or "loose",? if you're in Rio Linda!!)
On Sat, Feb 10, 2024 at 07:37 PM, Jim Shorney wrote:
OK guys, have a look at this close-up pic of a 3-500z. This was found in an L7 (not mine). That's not lens distortion or an optical illusion, it really looks like that. makes noise when you pick it up and move it around. This LOOKS like brand new tube. As does its partner. 93xx date codes, paint that looks fresh and not burned. I can't figure how this got out of the factory this way but it doesn't look like shipping damage to me. The wonky tube has a yellow dot sticker on top like someone knew... Wow. The moral of this story is always give unknown tubes a good look before you power them up. I hate to think of what would have happened if I had hit this one with full HV.
--
73
-Jim
NU0C
? --
73/Rick
W4XA
*Every post is created using Linux
|
Re: All bent out of shape (3-500z)
Yup..I forgot to add that to the message! Thanks Jim!
Joe- W7RKN
toggle quoted message
Show quoted text
-----Original Message----- From: [email protected] [mailto: [email protected]] On Behalf Of Jim Shorney Subject: Re: [DRAKE-RADIO] All bent out of shape (3-500z) You must ship with signature required. Otherwise they just drop the package on your porch and run. 73 -Jim NU0C
|
Re: TR-7 ALC Board Schematic
/g/DRAKE-RADIO/message/7607673 -Jim NU0C On Mon, 12 Feb 2024 08:47:22 -0800 "Dale Parfitt" <PARINC1@...> wrote: The service manual appears to skip over the ALC board schematic- or at least I am unable to find it.
Anyone enlighten me?
Tnx,
Dale W4OP
|
The service manual appears to skip over the ALC board schematic- or at least I am unable to find it.
Anyone enlighten me?
Tnx,
Dale W4OP
|
Re: All bent out of shape (3-500z)
You must ship with signature required. Otherwise they just drop the package on your porch and run. 73 -Jim NU0C On Mon, 12 Feb 2024 08:31:20 -0800 "Joe - W7RKN" <w7rkn.7@...> wrote: I just tell the receiver that if the sensor is missing, video the opening of the carton, *while the delivery person* is still there, making sure he/she is in the vid. -- 73 -Jim NU0C
|
Re: Another TR7 Journey begins
The ALC board is part of the High Pass Filter module. You will find the schematic on page 2-80. The inputs are clearly labeled. ALC photo is page 2-73. There is a very early ALC board that is a little different but I have only heard of one confirmed in the field so I have no data on when the final version was put in production. 73 -Jim NU0C On Mon, 12 Feb 2024 07:58:28 -0800 "Bill NZ0T" <nz0tham@...> wrote: I am attempying to do the wattmeter null adjustment.? The service manual that I downloded from the files section says to connect a VTVM to the refected power input on the ALC board (see section 2-15).? I have read the description of the ALC board there several times but I can't figure out where that input is.? There is no schematic or photo of the board that I can look at - maybe a page is missing?? Anyone know where that point is on the ALC board?
73, Bill NZ0T
-- 73 -Jim NU0C
|
Re: All bent out of shape (3-500z)
Shock sensors on and in the shipment would have removed any and all resistance to the claim by FedEx. Anything of value I ship, has shock sensors, inside and outside the box/shipping container.? To prevent the removal of the sensor, I put it on, outline it with a marks-a-lot then tape over it.? Then take a picture of it on the box.? I have had them removed.? The one inside shows what really happened.? I just tell the receiver that if the sensor is missing, video the opening of the carton, *while the delivery person* is still there, making sure he/she is in the vid.? If the inside sensor has been violated, and is missing on the outside of the box, the shipper will cringe at what will happen to them if the claim ever goes to court. ? Joe ¨C W7RKN ? ? As a side note, insurance claims via FedEx for damaged tubes may or may not be honored. ? Why? ?With an amp and some tubes (packed separately, double boxed, well packed) that I sent out, there was damage. ?Come to find out that "what we don't ship" did not exclude vacuum tubes, only x-ray tubes and a few others. ?However, I also found out that vacuum tubes were listed under "what we don't insure", on their website. ?It was a battle and with the support of the shipper, pictures, specs about g forces for the 3-500Z, etc. the insurance claim was finally honored by FedEx. ?
|
Re: Another TR7 Journey begins
I am attempying to do the wattmeter null adjustment.? The service manual that I downloded from the files section says to connect a VTVM to the refected power input on the ALC board (see section 2-15).? I have read the description of the ALC board there several times but I can't figure out where that input is.? There is no schematic or photo of the board that I can look at - maybe a page is missing?? Anyone know where that point is on the ALC board?
73, Bill NZ0T
|
Re: All bent out of shape (3-500z)
As a side note, insurance claims via FedEx for damaged tubes may or may not be honored. ? Why? ?With an amp and some tubes (packed separately, double boxed, well packed) that I sent out, there was damage. ?Come to find out that "what we don't ship" did not exclude vacuum tubes, only x-ray tubes and a few others. ?However, I also found out that vacuum tubes were listed under "what we don't insure", on their website. ?It was a battle and with the support of the shipper, pictures, specs about g forces for the 3-500Z, etc. the insurance claim was finally honored by FedEx. ?
73,
Evan, K9SQG
On Monday, February 12, 2024 at 03:51:44 AM EST, Jim VE7RF <jim.thom@...> wrote:
<This is a common problem of rough handling.? That is why it was ALWAYS said to never lay the Eimac tubes on the side, always standing up and to treat them like fine crystal.
<Vince N8MQV
Tell that to UPS, Fedex,? USPS? etc.?
|
Re: All bent out of shape (3-500z)
<This is a common problem of rough handling.? That is why it was ALWAYS said to never lay the Eimac tubes on the side, always standing up and to treat them like fine crystal.
<Vince N8MQV
Tell that to UPS, Fedex,? USPS? etc.?
|
Drake Technical Net - 11 February 2024
The Drake Technical Net met at 21:00z on Sunday, 11 February 2024 ? There were 39 stations checking in with us, today. The Drake radios used included the following: ? >> Drake Twins (all models): 12 ? >> Drake TR-3 Transceivers: 0 ? >> Drake TR-4 Transceivers (all models): 10 ? >> Drake TR5 Transceivers: 1 ? >> Drake TR7 / TR7A Transceivers: 9 ? The net operated under fairly good conditions and did not close until 22:19z. ? Join us again on Sunday, 18 February 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 11 February 2024 W9MXQ@... ? ?
|
Re: Another TR7 Journey begins
If you plan on doing CW you may want to also take a look at the article here by Floyd K8AC: 73 -Jim NU0C On Sun, 11 Feb 2024 11:22:56 -0800 "Bill NZ0T" <nz0tham@...> wrote: After fining the much better PDF copy of the sevice manual in the files here I have a plan to try tomorrow.
1.? Very low sidetone volume:? Check R1152 a 330 ohm on the IF/audio board to see if it's shorted, way out of tolerance or has been replaced with a different vvalue to lower the volume.? Maybe a PO wanted to use his keyer sidetone instead of the rig and with no sidetone adjutment in the rig that is how the PO soved it.
2.? Perform the null adjustment of C1901 on the rear LP assembly before I try adjusting the forward and reflected pots.? Maybe thats way out of adjustement and causing the other adjustments to not work which is affecting the ALC adjustment?? Worth a try.
I'll report back tomorrow.? But now it's time to cheer on my Chiefs!
73, Bill NZ0T
|
Re: Drake TR-7 - A repair journey
Mark, On Sun, 11 Feb 2024 11:02:15 -0800 "atlasstuff" <g4fph@...> wrote: @Mike: Thanks for you post. I hope you are in good health. I will send you an e-mail regarding the power supply board. TI and others have some amazing switching regulator IC's available these days. If I had time for a design challenge, it would be to have a go at replacing all of the linear regulators with them. The +24 and -5 Volt rails must run hardly any current. Has anyone measured the current draw on the +10 and +5 Volt rails. In any case, must be less than 5-Amp and 1-Amp respectively. The +24 supplies a boost voltage to the PLL for faster lock. The -5 back-biases the PIN diodes on the IF filter board and typically measures arounf -3 to -4. Not very critical it seems. I wouldn't go nuts about replacing the regulators. The original design is very good. There was a blurb in QST years ago about adding some bypass caps to the regulators to reduce noise. It may be in the group file section but if not I can probably dig it up. @Group: I now have the TR-7 transmitter working OK. The Drake 7077 mic that came with the radio sounded somewhat average, so I plugged in the Shure 444 that I use on my other TR-7. It didn't work - what!? The reason was that this low s/n TR-7 did not have the 470k resistor installed between pins 1 & 4 on the rear of the microphone socket. It now has, and the 444 sounds good. I was going to mention that eventually. I have a 7077. Not impressed with it. Most any other mic sounds better in my experience. The transmitter produces 100 W RF out up to and including 20 metres. On 15 metres, it's down to around 85 W. On 10 metres, it's down to about 25 W, so some work to do. Despite having a low s/n of just over 1000, this TR-7 has the MkII pre-driver board in the PA, whic I guess is a good thing. The ALC threshold is lowered by a pair of resistors on the band switch for 15 and 10 meters due to lower gain of the transistors at higher frequencies. A good PA deck should easily do 140+ on 20m and very close to 100 0n 15/10 when adjusted to service manual spec. The version 2 predriver was a standard upgrade by Drake service. Apparently they had a lot of trouble with the original. I have some 'talkback' / low-level undemodulated SSB getting back into the speaker when I transmit. Think I read somewhere that the early models were prone to this and that separating out the Hi- and Lo- Amps lines in the DC power lead (like Atlas did!) helps. I will try this. Any other tips for getting rid? That somewhere is probably here: Also check that you have a 470uF capacitor on the bottom side from pin 10 of the Power Supply board to chassis. I did have a nice find when I went digging to do the transmit carrier balance - an AUX 7 card installed, with the three Drake diode modules fitted for full 0 - 1.5 MHz receive coverage, plus a previous owner had made some, Christmas-tree style, modules for 30, 17 and 12 metres. So, I did have a bit of luck after all the pain! Lucky score! -- 73 -Jim NU0C
|
Re: Another TR7 Journey begins
After fining the much better PDF copy of the sevice manual in the files here I have a plan to try tomorrow.
1.? Very low sidetone volume:? Check R1152 a 330 ohm on the IF/audio board to see if it's shorted, way out of tolerance or has been replaced with a different vvalue to lower the volume.? Maybe a PO wanted to use his keyer sidetone instead of the rig and with no sidetone adjutment in the rig that is how the PO soved it.
2.? Perform the null adjustment of C1901 on the rear LP assembly before I try adjusting the forward and reflected pots.? Maybe thats way out of adjustement and causing the other adjustments to not work which is affecting the ALC adjustment?? Worth a try.
I'll report back tomorrow.? But now it's time to cheer on my Chiefs!
73, Bill NZ0T
|
Re: Drake TR-7 - A repair journey
@Tom: Thanks for those fixes. I will remember to go grab the updated version. Coming to the radio with zero practical experience of what was inside, just finding where to put the probe was a real challenge until I found your document.
@Mike: Thanks for you post. I hope you are in good health. I will send you an e-mail regarding the power supply board. TI and others have some amazing switching regulator IC's available these days. If I had time for a design challenge, it would be to have a go at replacing all of the linear regulators with them. The +24 and -5 Volt rails must run hardly any current. Has anyone measured the current draw on the +10 and +5 Volt rails. In any case, must be less than 5-Amp and 1-Amp respectively.
@Group: I now have the TR-7 transmitter working OK. The Drake 7077 mic that came with the radio sounded somewhat average, so I plugged in the Shure 444 that I use on my other TR-7. It didn't work - what!? The reason was that this low s/n TR-7 did not have the 470k resistor installed between pins 1 & 4 on the rear of the microphone socket. It now has, and the 444 sounds good.
The transmitter produces 100 W RF out up to and including 20 metres. On 15 metres, it's down to around 85 W. On 10 metres, it's down to about 25 W, so some work to do. Despite having a low s/n of just over 1000, this TR-7 has the MkII pre-driver board in the PA, whic I guess is a good thing.
I have some 'talkback' / low-level undemodulated SSB getting back into the speaker when I transmit. Think I read somewhere that the early models were prone to this and that separating out the Hi- and Lo- Amps lines in the DC power lead (like Atlas did!) helps. I will try this. Any other tips for getting rid?
I got to try out my jumper board, when I went to balance out the carrier. Would have been nice if Drake had put a suitable hole in the DR-7 board so the pot on the transmit exciter that needs adjusting was easily accessible <grumpy face>. I did have a nice find when I went digging to do the transmit carrier balance - an AUX 7 card installed, with the three Drake diode modules fitted for full 0 - 1.5 MHz receive coverage, plus a previous owner had made some, Christmas-tree style, modules for 30, 17 and 12 metres. So, I did have a bit of luck after all the pain!
Regards,
Mark.
|
FS-TR7 Transmit Exciter Board
I have a TR7 transmit exciter board for sale that be of use to someone.
I purchased it from K3ICH some time ago but no longer need it as I am selling the TR7, serial 4566.
If interested please contact me off line at? hpolkscw@....
Harold
N3HP
|
Jim Shorney
