Keyboard Shortcuts
ctrl + shift + ? :
Show all keyboard shortcuts
ctrl + g :
Navigate to a group
ctrl + shift + f :
Find
ctrl + / :
Quick actions
esc to dismiss
Likes
Search
8562E adventures
|
So my adventures in restoring this instrument continue.
The YTO I got from ebay had a definite intermittent short between one side of the FM coil and the -5 volt pin. I cut it open and this was a manufacturing defect. The ebay seller sent me another unit, which is fine.? He didn't give me a hard time at all, very honorable. So I mounted it in the instrument with the adapter plate I had made, hooked up the -5 volt regulator and everything else, and tried the YTO adjustments. I could set the low to the 3.200 GHz but I couldn't get the high to go to 6.010 GHz.? Not enough range in the adjustment pot.? In the circuit there are R44 and R126, each 100 ohm 0.1% resistors, in parallel, in the current sense part of the current source circuit. I found that an added 1K resistor in parallel would give me enough range so I added a high quality 1% 1K resistor there. I was then able to go back and forth on the low and high adjustments until they were right. However, that resistor might not be the right value even though I could get the adjustments to work, because I am getting an error 319, which is a warning that the coarse YTO tune DAC is near its limit. I will have to look at the DAC output to see if this is for the lower or upper limit and go from there. This is promising.? It looks like this substitute YTO might just end up working out. Peter |
|
An update.
toggle quoted message
Show quoted text
The Avantek YTO requires a lot more current to tune to the required frequencies than the HP YTO it replaces.? I was running into trouble because I was actually measuring the 2nd harmonic, which explained why it showed weak on the bench 8566A.? I was seeing minus some odd dBm where I would expect the 1st LO output should be around +10 dBm.? This is why I was having difficulties.? I needed to look lower in frequency than I thought for the strongest output. Tho get the Avantek to run at the needed frequencies required some circuit modifications. Bottom line, it required adding some extra resistors in parallel to the current sense resistors in the Q301 and Q302 circuits.? In each case, the two parallel 100 ohm resistors had to have added two each precision 76.8 ohm low TC resistors.? This moved the 50 ohm sense resistor to 21.72 ohms.? Once this was done, I was able to get the YTO tuning alignment completed successfully at 3.200 and 6.050 GHz per the manual. The Avantek main coil is 10 ohms while the HP coil was 39 ohms.? To limit dissipation in the drive transistors and sense resistors, I added a 20 ohm 5 watt resistor in series with the main coil, at the YTO.? At the 305 mA required at 6.050 GHz, it dissipates 1.8 watts. The power dissipation in components is calculated to be within limits. The analyzer errors disappeared and I can work further on it. I did notice that the drive transistor for the YTF is running VERY hot.? I will need to look into that. Peter On 3/18/2024 6:33 PM, Peter Gottlieb via groups.io wrote:
So my adventures in restoring this instrument continue. |
|
Now that I got that Avantek YTO to operate properly in the unit, I would like to once again see if I can find an outer case and handle for this thing.
toggle quoted message
Show quoted text
Due to insane international shipping costs I will want it to be in the USA. Anyone have any leads? Peter On 3/20/2024 11:23 AM, Peter Gottlieb via groups.io wrote:
An update. |
¿ªÔÆÌåÓý
Hello Peter what about drift I tried to mod a avantek YIG of the same type but I always end up with the drift of the YIG beeing greater than the Loop will handle and with occational you can choose between cold and hot for it to throw a Err301 YIG loop unlock.
maybe you have done something I have not mastered.
73 Peter OZ1LPR
Fra: [email protected] <[email protected]> p? vegne af Peter Gottlieb <hpnpilot@...>
Sendt: 20. marts 2024 23:44 Til: [email protected] <[email protected]> Emne: Re: [HP-Agilent-Keysight-equipment] 8562E adventures ?
Now that I got that Avantek YTO to operate properly in the unit, I would like to
once again see if I can find an outer case and handle for this thing. Due to insane international shipping costs I will want it to be in the USA. Anyone have any leads? Peter On 3/20/2024 11:23 AM, Peter Gottlieb via groups.io wrote: > An update. > > The Avantek YTO requires a lot more current to tune to the required > frequencies than the HP YTO it replaces.? I was running into trouble because I > was actually measuring the 2nd harmonic, which explained why it showed weak on > the bench 8566A.? I was seeing minus some odd dBm where I would expect the 1st > LO output should be around +10 dBm.? This is why I was having difficulties. I > needed to look lower in frequency than I thought for the strongest output. > > Tho get the Avantek to run at the needed frequencies required some circuit > modifications. > > Bottom line, it required adding some extra resistors in parallel to the > current sense resistors in the Q301 and Q302 circuits.? In each case, the two > parallel 100 ohm resistors had to have added two each precision 76.8 ohm low > TC resistors.? This moved the 50 ohm sense resistor to 21.72 ohms.? Once this > was done, I was able to get the YTO tuning alignment completed successfully at > 3.200 and 6.050 GHz per the manual. > > The Avantek main coil is 10 ohms while the HP coil was 39 ohms. To limit > dissipation in the drive transistors and sense resistors, I added a 20 ohm 5 > watt resistor in series with the main coil, at the YTO.? At the 305 mA > required at 6.050 GHz, it dissipates 1.8 watts. The power dissipation in > components is calculated to be within limits. > > The analyzer errors disappeared and I can work further on it. > > I did notice that the drive transistor for the YTF is running VERY hot.? I > will need to look into that. > > Peter > > > On 3/18/2024 6:33 PM, Peter Gottlieb via groups.io wrote: >> So my adventures in restoring this instrument continue. >> >> The YTO I got from ebay had a definite intermittent short between one side of >> the FM coil and the -5 volt pin. >> >> I cut it open and this was a manufacturing defect. >> >> The ebay seller sent me another unit, which is fine.? He didn't give me a >> hard time at all, very honorable. >> >> So I mounted it in the instrument with the adapter plate I had made, hooked >> up the -5 volt regulator and everything else, and tried the YTO adjustments. >> >> I could set the low to the 3.200 GHz but I couldn't get the high to go to >> 6.010 GHz.? Not enough range in the adjustment pot.? In the circuit there are >> R44 and R126, each 100 ohm 0.1% resistors, in parallel, in the current sense >> part of the current source circuit. I found that an added 1K resistor in >> parallel would give me enough range so I added a high quality 1% 1K resistor >> there. >> >> I was then able to go back and forth on the low and high adjustments until >> they were right. >> >> However, that resistor might not be the right value even though I could get >> the adjustments to work, because I am getting an error 319, which is a >> warning that the coarse YTO tune DAC is near its limit. >> >> I will have to look at the DAC output to see if this is for the lower or >> upper limit and go from there. >> >> This is promising.? It looks like this substitute YTO might just end up >> working out. >> >> Peter >> >> >> >> >> >> > > > > > > |
|
Did you connect up the internal PTC heater?
toggle quoted message
Show quoted text
On 3/21/2024 6:21 AM, Peter Hansen wrote:
Hello Peter what about drift I tried to mod a avantek YIG of the same type but I always end up with the drift of the YIG beeing greater than the Loop will handle and with occational you can choose between cold and hot for it to throw a Err301 YIG loop unlock. |
¿ªÔÆÌåÓý
hello Peter Yes of course The original one drift 2-3Mhz and the loop is designed for 10Mhz drift the Avantek drift 40Mhz due to heating of the YIG it self
but very interested in how you got it working. did you test cold and hot ?
best regards Peter
Fra: [email protected] <[email protected]> p? vegne af Peter Gottlieb <hpnpilot@...>
Sendt: 21. marts 2024 12:28 Til: [email protected] <[email protected]> Emne: Re: [HP-Agilent-Keysight-equipment] 8562E adventures ?
Did you connect up the internal PTC heater?
On 3/21/2024 6:21 AM, Peter Hansen wrote: > Hello Peter what about drift I tried to mod a avantek YIG of the same type but > I always end up with the drift of the YIG beeing greater than the Loop will > handle and with occational you can choose between cold and hot for it to throw > a Err301 YIG loop unlock. > maybe you have done something I have not mastered. > 73 Peter OZ1LPR > -------------------------------------------------------------------------------- > *Fra:* [email protected] > <[email protected]> p? vegne af Peter Gottlieb > <hpnpilot@...> > *Sendt:* 20. marts 2024 23:44 > *Til:* [email protected] > <[email protected]> > *Emne:* Re: [HP-Agilent-Keysight-equipment] 8562E adventures > Now that I got that Avantek YTO to operate properly in the unit, I would like to > once again see if I can find an outer case and handle for this thing. > > Due to insane international shipping costs I will want it to be in the USA. > > Anyone have any leads? > > Peter > > > > On 3/20/2024 11:23 AM, Peter Gottlieb via groups.io wrote: > > An update. > > > > The Avantek YTO requires a lot more current to tune to the required > > frequencies than the HP YTO it replaces.? I was running into trouble because I > > was actually measuring the 2nd harmonic, which explained why it showed weak on > > the bench 8566A.? I was seeing minus some odd dBm where I would expect the 1st > > LO output should be around +10 dBm.? This is why I was having difficulties. I > > needed to look lower in frequency than I thought for the strongest output. > > > > Tho get the Avantek to run at the needed frequencies required some circuit > > modifications. > > > > Bottom line, it required adding some extra resistors in parallel to the > > current sense resistors in the Q301 and Q302 circuits.? In each case, the two > > parallel 100 ohm resistors had to have added two each precision 76.8 ohm low > > TC resistors.? This moved the 50 ohm sense resistor to 21.72 ohms.? Once this > > was done, I was able to get the YTO tuning alignment completed successfully at > > 3.200 and 6.050 GHz per the manual. > > > > The Avantek main coil is 10 ohms while the HP coil was 39 ohms. To limit > > dissipation in the drive transistors and sense resistors, I added a 20 ohm 5 > > watt resistor in series with the main coil, at the YTO.? At the 305 mA > > required at 6.050 GHz, it dissipates 1.8 watts. The power dissipation in > > components is calculated to be within limits. > > > > The analyzer errors disappeared and I can work further on it. > > > > I did notice that the drive transistor for the YTF is running VERY hot.? I > > will need to look into that. > > > > Peter > > > > > > On 3/18/2024 6:33 PM, Peter Gottlieb via groups.io wrote: > >> So my adventures in restoring this instrument continue. > >> > >> The YTO I got from ebay had a definite intermittent short between one side of > >> the FM coil and the -5 volt pin. > >> > >> I cut it open and this was a manufacturing defect. > >> > >> The ebay seller sent me another unit, which is fine.? He didn't give me a > >> hard time at all, very honorable. > >> > >> So I mounted it in the instrument with the adapter plate I had made, hooked > >> up the -5 volt regulator and everything else, and tried the YTO adjustments. > >> > >> I could set the low to the 3.200 GHz but I couldn't get the high to go to > >> 6.010 GHz.? Not enough range in the adjustment pot.? In the circuit there are > >> R44 and R126, each 100 ohm 0.1% resistors, in parallel, in the current sense > >> part of the current source circuit. I found that an added 1K resistor in > >> parallel would give me enough range so I added a high quality 1% 1K resistor > >> there. > >> > >> I was then able to go back and forth on the low and high adjustments until > >> they were right. > >> > >> However, that resistor might not be the right value even though I could get > >> the adjustments to work, because I am getting an error 319, which is a > >> warning that the coarse YTO tune DAC is near its limit. > >> > >> I will have to look at the DAC output to see if this is for the lower or > >> upper limit and go from there. > >> > >> This is promising.? It looks like this substitute YTO might just end up > >> working out. > >> > >> Peter > >> > >> > >> > >> > >> > >> > > > > > > > > > > > > > > > > > > |
|
Depends what is meant by cold and hot.? I don't have an environmental chamber or anything like that.? It's around 15C in my lab and when "warmed up" from internal heater plus current through the main coil, which I think is the main source of heat in operation, it feels like it's about 40C.? So it's alright over that range.
toggle quoted message
Show quoted text
Is it the extra heat in the Avantek from coil resistance that makes more heat perhaps?? The Avantek has a 10 ohm coil compared to the HP's 39 ohm coil so it might outwardly seem like the HP would generate less heat, except that the HP only needs somewhere near 70 mA to hit the highest frequency while the Avantek needs over 300 mA.? Heat generation goes up linearly with resistance but as the square of current.? So the Avantek has roughly four times the coil loss heat generation than the HP. At some point HP bought Avantek which I find interesting.? Maybe someone here knows what the reasoning behind that business decision was. Peter P.S., I opened the old HP unit again and examined very carefully under a microscope.? There is no evidence of thermal or other damage to any of the semiconductor chips or bond wires internal to the unit.? I am going to verify the functionality of the external PCB components then try recentering the YIG sphere as I have seen posts by folks who have gotten this kind of oscillator working again (in other gear) by doing that.? Why?? Because it's a fun exercise. On 3/22/2024 3:45 AM, Peter Hansen wrote:
hello Peter Yes of course The original one drift 2-3Mhz and the loop is designed for 10Mhz drift the Avantek drift 40Mhz due to heating of the YIG it self |
|
HP bought Avantek because they used so many of their products (amp chips, transistors, yigs, packaged amps) and at that time military sales were good, esp. in the replacemnet part arena. I was in that world then. I guess it made good business sense to someone.
Jeff Kruth
In a message dated 3/22/2024 8:12:57 AM Eastern Standard Time, hpnpilot@... writes: ?
Depends what is meant by cold and hot.? I don't have an environmental chamber or anything like that.? It's around 15C in my lab and when "warmed up" from internal heater plus current through the main coil, which I think is the main source of heat in operation, it feels like it's about 40C.? So it's alright over that range. Is it the extra heat in the Avantek from coil resistance that makes more heat perhaps?? The Avantek has a 10 ohm coil compared to the HP's 39 ohm coil so it might outwardly seem like the HP would generate less heat, except that the HP only needs somewhere near 70 mA to hit the highest frequency while the Avantek needs over 300 mA.? Heat generation goes up linearly with resistance but as the square of current.? So the Avantek has roughly four times the coil loss heat generation than the HP. At some point HP bought Avantek which I find interesting.? Maybe someone here knows what the reasoning behind that business decision was. Peter P.S., I opened the old HP unit again and examined very carefully under a microscope.? There is no evidence of thermal or other damage to any of the semiconductor chips or bond wires internal to the unit.? I am going to verify the functionality of the external PCB components then try recentering the YIG sphere as I have seen posts by folks who have gotten this kind of oscillator working again (in other gear) by doing that.? Why?? Because it's a fun exercise. On 3/22/2024 3:45 AM, Peter Hansen wrote:
> hello Peter Yes of course The original one drift 2-3Mhz and the loop is > designed for 10Mhz drift the Avantek drift 40Mhz due to heating of the YIG it self > but very interested in how you got it working. did you test cold and hot ? > best regards Peter > -------------------------------------------------------------------------------- > *Fra:* [email protected] > <[email protected]> p? vegne af Peter Gottlieb > <hpnpilot@...> > *Sendt:* 21. marts 2024 12:28 > *Til:* [email protected] > <[email protected]> > *Emne:* Re: [HP-Agilent-Keysight-equipment] 8562E adventures > Did you connect up the internal PTC heater? > > > On 3/21/2024 6:21 AM, Peter Hansen wrote: > > Hello Peter what about drift I tried to mod a avantek YIG of the same type but > > I always end up with the drift of the YIG beeing greater than the Loop will > > handle and with occational you can choose between cold and hot for it to throw > > a Err301 YIG loop unlock. > > maybe you have done something I have not mastered. > > 73 Peter OZ1LPR > > -------------------------------------------------------------------------------- > > *Fra:* [email protected] > > <[email protected]> p? vegne af Peter Gottlieb > > <hpnpilot@...> > > *Sendt:* 20. marts 2024 23:44 > > *Til:* [email protected] > > <[email protected]> > > *Emne:* Re: [HP-Agilent-Keysight-equipment] 8562E adventures > > Now that I got that Avantek YTO to operate properly in the unit, I would like to > > once again see if I can find an outer case and handle for this thing. > > > > Due to insane international shipping costs I will want it to be in the USA. > > > > Anyone have any leads? > > > > Peter > > > > > > > > On 3/20/2024 11:23 AM, Peter Gottlieb via groups.io wrote: > > > An update. > > > > > > The Avantek YTO requires a lot more current to tune to the required > > > frequencies than the HP YTO it replaces.? I was running into trouble because I > > > was actually measuring the 2nd harmonic, which explained why it showed weak on > > > the bench 8566A.? I was seeing minus some odd dBm where I would expect the 1st > > > LO output should be around +10 dBm.? This is why I was having difficulties. I > > > needed to look lower in frequency than I thought for the strongest output. > > > > > > Tho get the Avantek to run at the needed frequencies required some circuit > > > modifications. > > > > > > Bottom line, it required adding some extra resistors in parallel to the > > > current sense resistors in the Q301 and Q302 circuits.? In each case, the two > > > parallel 100 ohm resistors had to have added two each precision 76.8 ohm low > > > TC resistors.? This moved the 50 ohm sense resistor to 21.72 ohms.? Once this > > > was done, I was able to get the YTO tuning alignment completed successfully at > > > 3.200 and 6.050 GHz per the manual. > > > > > > The Avantek main coil is 10 ohms while the HP coil was 39 ohms. To limit > > > dissipation in the drive transistors and sense resistors, I added a 20 ohm 5 > > > watt resistor in series with the main coil, at the YTO.? At the 305 mA > > > required at 6.050 GHz, it dissipates 1.8 watts. The power dissipation in > > > components is calculated to be within limits. > > > > > > The analyzer errors disappeared and I can work further on it. > > > > > > I did notice that the drive transistor for the YTF is running VERY hot.? I > > > will need to look into that. > > > > > > Peter > > > > > > > > > On 3/18/2024 6:33 PM, Peter Gottlieb via groups.io wrote: > > >> So my adventures in restoring this instrument continue. > > >> > > >> The YTO I got from ebay had a definite intermittent short between one side of > > >> the FM coil and the -5 volt pin. > > >> > > >> I cut it open and this was a manufacturing defect. > > >> > > >> The ebay seller sent me another unit, which is fine.? He didn't give me a > > >> hard time at all, very honorable. > > >> > > >> So I mounted it in the instrument with the adapter plate I had made, hooked > > >> up the -5 volt regulator and everything else, and tried the YTO adjustments. > > >> > > >> I could set the low to the 3.200 GHz but I couldn't get the high to go to > > >> 6.010 GHz.? Not enough range in the adjustment pot.? In the circuit there are > > >> R44 and R126, each 100 ohm 0.1% resistors, in parallel, in the current sense > > >> part of the current source circuit. I found that an added 1K resistor in > > >> parallel would give me enough range so I added a high quality 1% 1K resistor > > >> there. > > >> > > >> I was then able to go back and forth on the low and high adjustments until > > >> they were right. > > >> > > >> However, that resistor might not be the right value even though I could get > > >> the adjustments to work, because I am getting an error 319, which is a > > >> warning that the coarse YTO tune DAC is near its limit. > > >> > > >> I will have to look at the DAC output to see if this is for the lower or > > >> upper limit and go from there. > > >> > > >> This is promising.? It looks like this substitute YTO might just end up > > >> working out. > > >> > > >> Peter > > >> > > >> > > >> > > >> > > >> > > >> > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > |
to navigate to use esc to dismiss