Re: Wanted: 1500 Hz filter
Makes me wonder if Frank could produce a new 48.050-MHz filter for the TR7.?
Bob K9JU
On Saturday, December 21, 2024 at 07:54:23 PM EST, Floyd - K8AC via groups.io <floydsense@...> wrote:
Frank made up a 1500 Hz filter for me and just received it today.? Works perfectly.? I highly recommend Noble Radio for filters.
?
73, Floyd - K8AC
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Re: TR7 Digital Display +300Hz.
First check the??check the 10.0 volt supply. It needs to be dead on before any other adjustments.
Then check the 40 MHz reference oscillator. That controls all operating frequencies, including the display reading, in the TR7.
There are not a lot of other things that can cause a small error in frequency.?
The TR7 is a true frequency counter, unlike most radios. That means it takes the premix to the first mixer and subtracts it From the 48.05 MHz IF to give actual operating frequency. Only an error in the timebase (the 40 MHz reference) can cause errant display readings.
Gary
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On Dec 21, 2024, at 7:49?PM, Robin K4IDC via groups.io <RobinK4IDC@...> wrote:
A certain TR7 shows 300Hz. high on the digital display; tuning to the known correct frequency?for several nets such that the received audio sounds correct always results in a 300Hz. indication to the high side. Received reports confirm the same; transmitted audio sounds great when the digi display is?+300. Is there an easy solution? Google search isn't much help.
Thanks,
Robin Midgett K4IDC
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TR7 Digital Display +300Hz.
A certain TR7 shows 300Hz. high on the digital display; tuning to the known correct frequency?for several nets such that the received audio sounds correct always results in a 300Hz. indication to the high side. Received reports confirm the same; transmitted audio sounds great when the digi display is?+300. Is there an easy solution? Google search isn't much help.
Thanks,
Robin Midgett K4IDC
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Re: Wanted: 1500 Hz filter
Frank made up a 1500 Hz filter for me and just received it today.? Works perfectly.? I highly recommend Noble Radio for filters.
?
73, Floyd - K8AC
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Re: T4XB/R4B Transceive problem
Tony, AK4K Crystals has the 5.595-MHz crystal available as a stock item. Taking into inflation, the $32.00 price tag isn't "that" bad!
Bob K9JU
Maryville, TN
On Saturday, December 21, 2024 at 12:50:43 PM EST, kg9hfrank@... via groups.io <kg9hfrank@...> wrote:
I used to use Motorola Crystal Ovens from T43-GGV, etc, 6VDC, 2 in series run off of 12VDC to do that. ? ? ?Frank Krozel Life Member, ARRL ? ? (630) 924-1600 kg9hfrank@...
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If you have good 500 kHz on the board make sure the protection circuit is working properly. Q9011 should be biased on to provide GND to the LED's. If not, none of them will work.
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Re: R4C need PCB foil diagram
On 2024-12-21 06:13, Jay W6CJ via groups.io wrote: Throw away radios.. just like cell phones and all new gadgets.
I am sure loving my old ancient Kenwoods and Drakes... easy and
cheap to fix, modify and enjoy!
*** Indeed. I had a QSO on one of the forever discussion groups on 40M. The net control was flabbergasted that I had managed to fix a Signal/One. I tried to explain that it was really a fairly straightforward radio, and nowhere near the same ballpark of difficulty as the modern stuff, which generally consists of: 1 big board... with a giant 200-pin ASIC in the middle. - Jerry, KF6VB
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Scratch that. I just looked at the schematic again (since I just finished stitching the three scanned images back into a single schematic) and the Full Coverage section (U9001 through U9008) gets its 5V from the Digital Control board underneath the DR7. This would not make the counter go dark. Look for the 500 KHz reference signal as was suggested in another post. You may have some Parent Board Molexia going on somewhere. Thinking about that schematic after I went to the trouble of stitching it, it occurs to me that it might be sensible to also break it up into four distinct sections: Full Coverage Input Counter (dividers and timebase) LED Display and Drive That's a project for another day as I just know I would feel compelled to clean up some areas that have poor readability. Right now I need to go play with some RF. On Sat, 21 Dec 2024 13:44:35 -0600 "Jim Shorney via groups.io" <jimNU0C@...> wrote: the common 5V rail coming from U9033. -- 73 -Jim NU0C
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Just as a side note, 9001 through 9008 are not related to the frequency counter. They deal with PLL N codes that are passed from the Digital Control Board to the Translator Board. That's not discount the possibility that you might have an open trace somewhere in the common 5V rail coming from U9033. My rule with boards this old is "never trust a via". That includes pass-throughs at the Molex male pins and IC pins. On Sat, 21 Dec 2024 15:16:41 -0400 "Jim Harris via groups.io" <radiove1rb@...> wrote: Okay, I have been working on the DR7 board and I found that the following
I.C's do not have any Plus 5 volts DC on them. They are U9001, U0002,
U9003, U9004, U9005, U9006, U9007, and U9008. -- 73 -Jim NU0C
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Okay, I have been working on the DR7 board and I found that the following I.C's do not have any Plus 5 volts DC on them. They are U9001, U0002, U9003, U9004, U9005, U9006, U9007, and U9008. I do have the service manual but the schematic does not show me where the 5 VDC is coming?from and what it is going through. I do have 5 VDC coming out of the 2 7805 regulators okay. All of the other I.C's have the 5VDC on them okay. I will remove the DR7 board?for a third?time today and try to follow the line back from resistors?R9003 R9004 R9005 and R9006 as they do not have any 5VDC either. Thanks guys for the help. Any further suggestions are always welcome.
73, Jim VE1RB
[Edited Message Follows]
"withe the NORM/EXT set in EXT, the display should be on, and showing 00000"?
mike wb8vge
?
Actually, EXT mode with no sample port input, DR-7 should blank with only the 100hz dot illuminated.
All zeroes display would only occur when EXT input signal is exactly 100MHz.??
Jim WA9Z?
?
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Re: T4XB/R4B Transceive problem
I used to use Motorola Crystal Ovens from T43-GGV, etc, 6VDC, 2 in series run off of 12VDC to do that.
? ? ?Frank Krozel Life Member, ARRL ? ? (630) 924-1600 kg9hfrank@...
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Re: T4XB/R4B Transceive problem
As good as they are, crystals "age" and tend to move down in frequency. I believe it is due to the little contamination inside the can that migrates to the blank, thus loading it to a lower frequency.?
I presume you have run the?"tweaking" capacitor of the R-4B through its entire range. If yes, then sometimes baking the crystal works. If I remember correctly, from this forum, 350 F to 375 F for 2 to 3 hours might get it back to nominal and within range of the tweaking capacitor.
If someone remembers the temperature and time for crystal baking, please chime in.
GL, Tony.
73, Bob K9JU
On Saturday, December 21, 2024 at 08:14:15 AM EST, Steve Wedge, W1ES/4 via groups.io <w1es@...> wrote:
I have seen crystals go off frequency. Just worked on an R-4C with the 5645 Xtal sitting at 5642. Crystals off by that much cannot be ¡°rubbered¡± to 5645. The solution with that receiver was to replace the Xtal.?
AF4K has them in stock for $25 plus shipping. They aren¡¯t HC-6 (they¡¯re quite small) but they are dead-on.?
You will need to find out which (tx or rx) is off and go from there.?
73,
Steve Wedge, W1ES
Time flies like an arrow. Fruit flies like a banana.
On Sat, Dec 21, 2024 at 01:46, Tony Sokol via groups.io < tony.sokol@...> wrote: ? ? Hey Bob, glad to hear that all is well in TN. Yeah, when I fudged the transmitter carrier frequency to net with the receiver is when things got snaky with the USB/LSB imbalance. Sooo¡I went back and adjusted the TX4B¡¯s carrier frequency so it is perfectly balanced between the filters. I used a VTVM to balance the audio output which made the job a little easier. The transmit audio sounds excellent now on both side bands but C61 is maxed out and can¡¯t quite make it on frequency. I tried padding it which didn¡¯t make much difference. Maybe I need more C or the rock has changed over time. I think I need to put it back on the bench and look at the actual frequency with my HP counter at this point.?
Have a Very Merry Christmas and a great New Year my friend. I¡¯ll keep you updated.?
? ? ? ? ?73
Tony - W9JXN?
Dundee, IL
On Dec 20, 2024, at 7:12?PM, Bob Loving via groups.io <bob.loving@...> wrote:
?
HI, Tony.
From your description of bassy on LSB and squeaky on USB, the carrier oscillator is not in the middle of the two sideband filters of the T-4XB. If I were you, I'd adjust the frequency of the carrier oscillator in the T-4XB first to get both sidebands to sound equal. This will be easier with an external receiver other than the R-4B. Then make the adjustment to the R-4B so that received signals sounds correct.
Hey, I have been in Dixie for 9-years and I love TN. I hope all is well in my birth state. Merry Christmas and Happy New Year, my friend.
73,
Bob Loving K9JU
Maryville, TN
On Friday, December 20, 2024 at 07:34:29 PM EST, Tony Sokol via groups.io <tony.sokol@...> wrote:
Thanks Steve.?
? ? ? I did try fudging the transmitter and got them to sync but it went too far. Had great base on LSB but on USB I was accused of having shorts that were too tight. ;-). I think need to check the receive crystal frequency and oscillator components. I noticed the crystal has a green dab of paint on it possibly meaning it was graded for certain circuit anomalies during final assembly.?
Tony
???
On Dec 20, 2024, at 6:41?AM, Steve Wedge, W1ES/4 via groups.io <w1es@...> wrote:
?
Tony, there is a chance that either the CO crystal in either the TX or RX has drifted or that one of the passband filters in the tx has drifted. I have a set of B Twins that suffered the same problem and I adjusted the CO in the tx just a little bit to allow everything to meet up. Only a very small change of the tx CO is needed.?
C61 only changes the frequency by about 450 Hz. I used the spectrum display in my modern rig (an Elecraft P3 at the time) to watch where the oscillator was via a piece of wire placed near the CO of each unit. A spectrum analyser can do the same thing.?
73,
Steve Wedge, W1ES
Time flies like an arrow. Fruit flies like a banana.
On Thu, Dec 19, 2024 at 19:11, Tony Sokol via groups.io <
tony.sokol@...> wrote:
Hi Gang,
I have a problem using C61 to net the R4B to the T4XB. The T4XB is perfectly centered in the filter passband according to the alignment instructions in the manual but it doesn¡¯t quite make it. Before I pull the receiver off the shelf and check the IF Xtal frequency I thought I'd run it by the group for ideas. I did try paddling C61 but it didn¡¯t seem to move much. Maybe not enough C paddling? Thoughts before I give K4AX Crystals a call?
Tony - W9JXN
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"withe the NORM/EXT set in EXT, the display should be on, and showing 00000"?
mike wb8vge
?
Actually, EXT mode with no sample port input, DR-7 should blank with only the 100hz dot illuminated.
All zeroes display would only occur when EXT input signal is exactly 100MHz.??
Jim WA9Z?
?
|
Check for the 500 kHz signal coming from the PBT/Reference board. There is a protection circuit in the DR7 that shuts off the LEDs when the 500 kHz is missing.
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Re: R4C need PCB foil diagram
You ship your brand E, I, K, or Y radio for repair and they charge you just to look at it. Guess what they are going to tell you after charging you to look at it: (A) non-repairable (B) parts availability issue Nice scam.
73 de? W6CJ
On Fri, Dec 20, 2024 at 06:24 PM, jerry-KF6VB wrote:
I consulted with Tim at Yaesu support - they don't fix'em either. Just
replace. About a grand...kaChing!
OMG!? Those aren't HAM radios anymore.? Aren't those only about $1200 new (with a warantee)?
Throw away radios.. just like cell phones and all new gadgets.
I am sure loving my old ancient Kenwoods and Drakes...? easy and cheap to fix, modify and enjoy!
?
73,
Gary
WB6OGD
?
|
Re: T4XB/R4B Transceive problem
I have seen crystals go off frequency. Just worked on an R-4C with the 5645 Xtal sitting at 5642. Crystals off by that much cannot be ¡°rubbered¡± to 5645. The solution with that receiver was to replace the Xtal.?
AF4K has them in stock for $25 plus shipping. They aren¡¯t HC-6 (they¡¯re quite small) but they are dead-on.?
You will need to find out which (tx or rx) is off and go from there.?
73,
Steve Wedge, W1ES
Time flies like an arrow. Fruit flies like a banana.
On Sat, Dec 21, 2024 at 01:46, Tony Sokol via groups.io < tony.sokol@...> wrote: ? ? Hey Bob, glad to hear that all is well in TN. Yeah, when I fudged the transmitter carrier frequency to net with the receiver is when things got snaky with the USB/LSB imbalance. Sooo¡I went back and adjusted the TX4B¡¯s carrier frequency so it is perfectly balanced between the filters. I used a VTVM to balance the audio output which made the job a little easier. The transmit audio sounds excellent now on both side bands but C61 is maxed out and can¡¯t quite make it on frequency. I tried padding it which didn¡¯t make much difference. Maybe I need more C or the rock has changed over time. I think I need to put it back on the bench and look at the actual frequency with my HP counter at this point.?
Have a Very Merry Christmas and a great New Year my friend. I¡¯ll keep you updated.?
? ? ? ? ?73
Tony - W9JXN?
Dundee, IL
On Dec 20, 2024, at 7:12?PM, Bob Loving via groups.io <bob.loving@...> wrote:
?
HI, Tony.
From your description of bassy on LSB and squeaky on USB, the carrier oscillator is not in the middle of the two sideband filters of the T-4XB. If I were you, I'd adjust the frequency of the carrier oscillator in the T-4XB first to get both sidebands to sound equal. This will be easier with an external receiver other than the R-4B. Then make the adjustment to the R-4B so that received signals sounds correct.
Hey, I have been in Dixie for 9-years and I love TN. I hope all is well in my birth state. Merry Christmas and Happy New Year, my friend.
73,
Bob Loving K9JU
Maryville, TN
On Friday, December 20, 2024 at 07:34:29 PM EST, Tony Sokol via groups.io <tony.sokol@...> wrote:
Thanks Steve.?
? ? ? I did try fudging the transmitter and got them to sync but it went too far. Had great base on LSB but on USB I was accused of having shorts that were too tight. ;-). I think need to check the receive crystal frequency and oscillator components. I noticed the crystal has a green dab of paint on it possibly meaning it was graded for certain circuit anomalies during final assembly.?
Tony
???
On Dec 20, 2024, at 6:41?AM, Steve Wedge, W1ES/4 via groups.io <w1es@...> wrote:
?
Tony, there is a chance that either the CO crystal in either the TX or RX has drifted or that one of the passband filters in the tx has drifted. I have a set of B Twins that suffered the same problem and I adjusted the CO in the tx just a little bit to allow everything to meet up. Only a very small change of the tx CO is needed.?
C61 only changes the frequency by about 450 Hz. I used the spectrum display in my modern rig (an Elecraft P3 at the time) to watch where the oscillator was via a piece of wire placed near the CO of each unit. A spectrum analyser can do the same thing.?
73,
Steve Wedge, W1ES
Time flies like an arrow. Fruit flies like a banana.
On Thu, Dec 19, 2024 at 19:11, Tony Sokol via groups.io <
tony.sokol@...> wrote:
Hi Gang,
I have a problem using C61 to net the R4B to the T4XB. The T4XB is perfectly centered in the filter passband according to the alignment instructions in the manual but it doesn¡¯t quite make it. Before I pull the receiver off the shelf and check the IF Xtal frequency I thought I'd run it by the group for ideas. I did try paddling C61 but it didn¡¯t seem to move much. Maybe not enough C paddling? Thoughts before I give K4AX Crystals a call?
Tony - W9JXN
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Re: R4C need PCB foil diagram
I have resorted to disconnecting the board by removing the wires and leads., rather than have to navigate a 700¡ã iron down to the bottom.?
The design was still, overall, 1950s/60s. With circuit boards that were hard-wired together.?
It is less work to remove the board that try and repair all of the melted wires.?
73,
Steve Wedge, W1ES
Time flies like an arrow. Fruit flies like a banana.
On Fri, Dec 20, 2024 at 19:01, mike bryce via groups.io < prosolar@...> wrote: This is one of the reasons why I don¡¯t care to work on the R4C. I know space was a premium, but damn, getting to the bottom of most of those boards even to make voltage checks is a PITA!
mike wb8vge
The Heathkit Shop
On Dec 20, 2024, at 3:28 PM, Evan via
<
k9sqg@...> wrote:
Jay,
You might want to id which of the three production runs/models you have in case this board is one of the "variables".
73,
Evan, K9SQG
Looking for a PC board foil diagram that shows the connections to, and around the R55 bias pot.??
Thanks & 73
Jay
W6CJ
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Re: T4XB/R4B Transceive problem
? ? Hey Bob, glad to hear that all is well in TN. Yeah, when I fudged the transmitter carrier frequency to net with the receiver is when things got snaky with the USB/LSB imbalance. Sooo¡I went back and adjusted the TX4B¡¯s carrier frequency so it is perfectly balanced between the filters. I used a VTVM to balance the audio output which made the job a little easier. The transmit audio sounds excellent now on both side bands but C61 is maxed out and can¡¯t quite make it on frequency. I tried padding it which didn¡¯t make much difference. Maybe I need more C or the rock has changed over time. I think I need to put it back on the bench and look at the actual frequency with my HP counter at this point.?
Have a Very Merry Christmas and a great New Year my friend. I¡¯ll keep you updated.? ? ? ? ? ?73 Tony - W9JXN? Dundee, IL
toggle quoted message
Show quoted text
On Dec 20, 2024, at 7:12?PM, Bob Loving via groups.io <bob.loving@...> wrote:
?
HI, Tony.
From your description of bassy on LSB and squeaky on USB, the carrier oscillator is not in the middle of the two sideband filters of the T-4XB. If I were you, I'd adjust the frequency of the carrier oscillator in the T-4XB first to get both sidebands to sound equal. This will be easier with an external receiver other than the R-4B. Then make the adjustment to the R-4B so that received signals sounds correct.
Hey, I have been in Dixie for 9-years and I love TN. I hope all is well in my birth state. Merry Christmas and Happy New Year, my friend.
73, Bob Loving K9JU
Maryville, TN
On Friday, December 20, 2024 at 07:34:29 PM EST, Tony Sokol via groups.io <tony.sokol@...> wrote:
Thanks Steve.? ? ? ? I did try fudging the transmitter and got them to sync but it went too far. Had great base on LSB but on USB I was accused of having shorts that were too tight. ;-). I think need to check the receive crystal frequency and oscillator components. I noticed the crystal has a green dab of paint on it possibly meaning it was graded for certain circuit anomalies during final assembly.?
Tony ??? On Dec 20, 2024, at 6:41?AM, Steve Wedge, W1ES/4 via groups.io <w1es@...> wrote:
? Tony, there is a chance that either the CO crystal in either the TX or RX has drifted or that one of the passband filters in the tx has drifted. I have a set of B Twins that suffered the same problem and I adjusted the CO in the tx just a little bit to allow everything to meet up. Only a very small change of the tx CO is needed.?
C61 only changes the frequency by about 450 Hz. I used the spectrum display in my modern rig (an Elecraft P3 at the time) to watch where the oscillator was via a piece of wire placed near the CO of each unit. A spectrum analyser can do the same thing.?
73,
Steve Wedge, W1ES
Time flies like an arrow. Fruit flies like a banana.
On Thu, Dec 19, 2024 at 19:11, Tony Sokol via groups.io < tony.sokol@...> wrote: Hi Gang,
I have a problem using C61 to net the R4B to the T4XB. The T4XB is perfectly centered in the filter passband according to the alignment instructions in the manual but it doesn¡¯t quite make it. Before I pull the receiver off the shelf and check the IF Xtal frequency I thought I'd run it by the group for ideas. I did try paddling C61 but it didn¡¯t seem to move much. Maybe not enough C paddling? Thoughts before I give K4AX Crystals a call?
Tony - W9JXN
|
Re: R4C need PCB foil diagram
On Fri, Dec 20, 2024 at 06:24 PM, jerry-KF6VB wrote:
I consulted with Tim at Yaesu support - they don't fix'em either. Just
replace. About a grand...kaChing!
OMG!? Those aren't HAM radios anymore.? Aren't those only about $1200 new (with a warantee)?
Throw away radios.. just like cell phones and all new gadgets.
I am sure loving my old ancient Kenwoods and Drakes...? easy and cheap to fix, modify and enjoy!
?
73,
Gary
WB6OGD
?
|
On 2024-12-20 18:41, Jim Shorney via groups.io wrote: 5W ) is another suspect. Side note, there is no "backwards" for the
four pin Molex. Drake cleverly wired it so it will work either way. *** AND, they put all four pins. I replaced the female Molex with a new one, and wired up all the pins. It still works either way. - Jerry, KF6VB
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Robin K4IDC
Floyd - K8AC
Jeff W7KNX
Jim Shorney
Jay W6CJ
Gary WB6OGD