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Re: Simpler spur fix
¿ªÔÆÌåÓýdue to the high current capability i assume that this choke is to
be used in DC DC converters and not at RF i.e. 45 MHz! Am 14.10.2018 um 18:36 schrieb Gary
Hanson:
Here is a part number for 680 nh smd inductor from Arrow electronics. ?Data sheet available on product page. ?Looks like the size is a 1212. ?I have not tried it yet, but specs look about right |
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Simpler spur fix
¿ªÔÆÌåÓýHere is a part number for 680 nh smd inductor from Arrow electronics. ?Data sheet available on product page. ?Looks like the size is a 1212. ?I have not tried it yet, but specs look about rightASPI-M3015-R68M-T? |
| EU RoHS | Supplier Unconfirmed? |
| ECCN (US) | EAR99 |
| Type | Power |
| Technology | Wirewound |
| Inductance (H) | 680n |
| Tolerance | 20% |
| Inductance Test Frequency (Hz) | 100K |
| Maximum DC Current (A) | 4.1 |
| Maximum Saturation Current (A) | 8 |
| Maximum DC Resistance (Ohm) | 35m |
| Number of Terminals | 2 |
| Case Size | 1212 |
| Minimum Operating Temperature (¡ãC) | -40 |
| Maximum Operating Temperature (¡ãC) | 125 |
| Mounting | Surface Mount |
| Product Length (mm) | 3.2 |
| Product Depth (mm) | 3.2 |
| Product Height (mm) | 1.5 |
Gary, KJ5VW
Re: Harmonics and Relay Replacement
Jim Sheldon
Raj,
Rather than just using double shielded coax from the 2 pin RF plug on the uBITX to the BNC, I carefully installed gold plated female SMA connector and that should help some but I'm just using the SMA on my test rig. The other ones are faring well enough and legal so I'm leaving them as-is. I changed my mind on the machined pin sockets and modified some old Mica filled DIP sockets I had on hand from many years ago. I pulled the unused contacts out so have Mica dielectric between pins and these sit up about 2mm off the board. Should be interesting to see the results. Be Wednesday before all the parts get here so I'll report the results in a few days.
I will add the SMA inductors in place of L5 and L7 though and found the Murata 1206 ones at Mouser. 10 on order and that will cover the 5 rigs I have.
Jim - W0EB
toggle quoted message
Show quoted text
Rather than just using double shielded coax from the 2 pin RF plug on the uBITX to the BNC, I carefully installed gold plated female SMA connector and that should help some but I'm just using the SMA on my test rig. The other ones are faring well enough and legal so I'm leaving them as-is. I changed my mind on the machined pin sockets and modified some old Mica filled DIP sockets I had on hand from many years ago. I pulled the unused contacts out so have Mica dielectric between pins and these sit up about 2mm off the board. Should be interesting to see the results. Be Wednesday before all the parts get here so I'll report the results in a few days.
I will add the SMA inductors in place of L5 and L7 though and found the Murata 1206 ones at Mouser. 10 on order and that will cover the 5 rigs I have.
Jim - W0EB
------ Original Message ------
From: "Raj vu2zap" <rajendrakumargg@...>
To: [email protected]
Sent: 10/14/2018 7:57:58 AM
Subject: Re: [BITX20] Harmonics and Relay Replacement
From: "Raj vu2zap" <rajendrakumargg@...>
To: [email protected]
Sent: 10/14/2018 7:57:58 AM
Subject: Re: [BITX20] Harmonics and Relay Replacement
GM Jim,
At 14/10/2018, you wrote:Raj,400mW is 33mA that should be OK for the transistors. I will try lower current one when I find a cheaper source or a vendor who will send
I thought the same thing, but maybe, even using sockets, just for the experiment, I could get some relative comparisons between the types to see if any were better than others. I suspect the 500mw version, Arrow part# V23105A5503A201 will be the best because they have the lowest coil resistance, fewest turns on the coil. The only thing that worries me using that relay is it's current draw - I'm hoping it won't be too much for the switching transistors in the uBITX. The 400mW relays are working and switching OK but the additional current from the lower coil resistance may become a problem and I'm not sure yet.
me by USPS.I don't want to risk ruining the board by soldering and unsoldering the relays several times so planned on using sockets but ONLY on the one board I'm planning on setting up as a test station. I'll build it up on a board but use double shielded Teflon insulated COAX from the uBITX boards 2 pin connector to the BNC output and make all digital and audio wires twisted pair to the front panel jacks, encoder and switch. The construction will be open, no case but the uBITX board will be mounted on a 16 gauge aluminum plate to give a good underside ground plane and good low Z grounds for all connections.Thats sensible, I put in sockets for the same reason. That board with L5/7 changed had spurs below -50dbm and its put to rest.
I was thrilled with Mike Doty's find (Remember Roy Doty ? - PopSci). I ordered the same 400mW relays as I thought that lower
power ones MAY be a little different in construction. Just KT1,2,3 change should do the trick. The other two don't play much
of a part in harmonics leaking through.
I tried a lot of mods, most gave a few dbs of improvement while others made things worse. The fix that makes dramatic improvement is
the root of the problem. For spurs the TX signal leaking into the first mixer was cured with TX losses with a 45MHz filter.. further thinking
led me to L5 and its position made a difference but not a fix.. the SMD for L5 made a big difference. Sort of a eureka moment!
High Q inductor in this board layout is not in best interest of impedance matching.. we are only stepping up 50 to 650 Ohms and back.
I need to experiment with a tapped toroid 2:7 without the caps and see - that might also fix the spurs issue. I wish someone would try
that and report - I am at my farm.I have some good, gold plated machined pin socket strips that are very low profile and will use those to create the sockets. Again, for these tests I will only look for which of the 4 relay types gives the best harmonic attenuation between types and then I will solder that set into a uBITX for the final results. Only way I know to test all 4 types without possibly ruining a good board from too much soldering/de-soldering of relays. A repaired trace would negate the original test results as it's characteristics would be different.I read you! I added the same pins. With a collaboration like this group we will make a great and simple exciter / QRP rig!
Hope people can understand what I'm trying to say here.Jim
Raj------ Original Message ------
From: "Raj vu2zap" <rajendrakumargg@...>
To: [email protected]
Sent: 10/14/2018 1:06:47 AM
Subject: Re: [BITX20] Harmonics and Relay ReplacementJim,
My take on this relay business is that both contacts are being inductively coupled.
Imagine the NC contacts on one side - it is a loop and will be inductive. The same goes
for the other pair on the other side..
By adding a socket we may not get the best rejection from Axicom relays. I have also
socketed KT1/2/3 .. the relays have arrived and I am at the farm.. so a week more
of suspense.
If someone with a SA like 815 can feed in the tracking gen through a 47 ohm resistor
to one NC contacts in/out and take the Analyser input from the other NC contact set
and then sweep say up to 100MHz, we get some enlightenment. I am eagerly waiting
to try for myself.
Raj
At 13/10/2018, you wrote:Looking at the differences between the original Hongfa relays -S (for sensitive) version in my uBITX boards and the Axicom relays Mike Doty and I installed in place of them, the Axicom had lower coil resistance in the 400 mW coils vs the 200 mW coils fot the Hongfa relays. That means fewer turns of wire in the Axicoms and subsequently less inductance. That may be a huge factor in the isolation between the two types. The coil resistance for the Axicom that matches the Hongfa in DC spec aldo has the exact same listed coil resistance.
I'm going to order 5 each of the 150mW, 200 mW and 500 mW versions, put sockets on my 3rd V4 board and see how much difference there is between the 3 other types relative to the already installed 400 mw version. Hopefully that will give us some definitive answers. Be Monday before I can order them so it will be a few days before any testing can be done.
Jim Sheldon, W0EB
_Dave_ AD0B
Re: Harmonics and Relay Replacement
Raj vu2zap
GM Jim,
At 14/10/2018, you wrote:
me by USPS.
I was thrilled with Mike Doty's find (Remember Roy Doty ? - PopSci). I ordered the same 400mW relays as I thought that lower
power ones MAY be a little different in construction. Just KT1,2,3 change should do the trick. The other two don't play much
of a part in harmonics leaking through.
I tried a lot of mods, most gave a few dbs of improvement while others made things worse. The fix that makes dramatic improvement is
the root of the problem. For spurs the TX signal leaking into the first mixer was cured with TX losses with a 45MHz filter.. further thinking
led me to L5 and its position made a difference but not a fix.. the SMD for L5 made a big difference. Sort of a eureka moment!
High Q inductor in this board layout is not in best interest of impedance matching.. we are only stepping up 50 to 650 Ohms and back.
I need to experiment with a tapped toroid 2:7 without the caps and see - that might also fix the spurs issue. I wish someone would try
that and report - I am at my farm.
Raj
At 14/10/2018, you wrote:
Raj,400mW is 33mA that should be OK for the transistors. I will try lower current one when I find a cheaper source or a vendor who will send
I thought the same thing, but maybe, even using sockets, just for the experiment, I could get some relative comparisons between the types to see if any were better than others. I suspect the 500mw version, Arrow part# V23105A5503A201 will be the best because they have the lowest coil resistance, fewest turns on the coil. The only thing that worries me using that relay is it's current draw - I'm hoping it won't be too much for the switching transistors in the uBITX. The 400mW relays are working and switching OK but the additional current from the lower coil resistance may become a problem and I'm not sure yet.
me by USPS.
I don't want to risk ruining the board by soldering and unsoldering the relays several times so planned on using sockets but ONLY on the one board I'm planning on setting up as a test station. I'll build it up on a board but use double shielded Teflon insulated COAX from the uBITX boards 2 pin connector to the BNC output and make all digital and audio wires twisted pair to the front panel jacks, encoder and switch. The construction will be open, no case but the uBITX board will be mounted on a 16 gauge aluminum plate to give a good underside ground plane and good low Z grounds for all connections.Thats sensible, I put in sockets for the same reason. That board with L5/7 changed had spurs below -50dbm and its put to rest.
I was thrilled with Mike Doty's find (Remember Roy Doty ? - PopSci). I ordered the same 400mW relays as I thought that lower
power ones MAY be a little different in construction. Just KT1,2,3 change should do the trick. The other two don't play much
of a part in harmonics leaking through.
I tried a lot of mods, most gave a few dbs of improvement while others made things worse. The fix that makes dramatic improvement is
the root of the problem. For spurs the TX signal leaking into the first mixer was cured with TX losses with a 45MHz filter.. further thinking
led me to L5 and its position made a difference but not a fix.. the SMD for L5 made a big difference. Sort of a eureka moment!
High Q inductor in this board layout is not in best interest of impedance matching.. we are only stepping up 50 to 650 Ohms and back.
I need to experiment with a tapped toroid 2:7 without the caps and see - that might also fix the spurs issue. I wish someone would try
that and report - I am at my farm.
I have some good, gold plated machined pin socket strips that are very low profile and will use those to create the sockets. Again, for these tests I will only look for which of the 4 relay types gives the best harmonic attenuation between types and then I will solder that set into a uBITX for the final results. Only way I know to test all 4 types without possibly ruining a good board from too much soldering/de-soldering of relays. A repaired trace would negate the original test results as it's characteristics would be different.I read you! I added the same pins. With a collaboration like this group we will make a great and simple exciter / QRP rig!
Hope people can understand what I'm trying to say here.
Jim
Raj
------ Original Message ------
From: "Raj vu2zap" <rajendrakumargg@...>
To: [email protected]
Sent: 10/14/2018 1:06:47 AM
Subject: Re: [BITX20] Harmonics and Relay ReplacementJim,
My take on this relay business is that both contacts are being inductively coupled.
Imagine the NC contacts on one side - it is a loop and will be inductive. The same goes
for the other pair on the other side..
By adding a socket we may not get the best rejection from Axicom relays. I have also
socketed KT1/2/3 .. the relays have arrived and I am at the farm.. so a week more
of suspense.
If someone with a SA like 815 can feed in the tracking gen through a 47 ohm resistor
to one NC contacts in/out and take the Analyser input from the other NC contact set
and then sweep say up to 100MHz, we get some enlightenment. I am eagerly waiting
to try for myself.
Raj
At 13/10/2018, you wrote:Looking at the differences between the original Hongfa relays -S (for sensitive) version in my uBITX boards and the Axicom relays Mike Doty and I installed in place of them, the Axicom had lower coil resistance in the 400 mW coils vs the 200 mW coils fot the Hongfa relays. That means fewer turns of wire in the Axicoms and subsequently less inductance. That may be a huge factor in the isolation between the two types. The coil resistance for the Axicom that matches the Hongfa in DC spec aldo has the exact same listed coil resistance.
I'm going to order 5 each of the 150mW, 200 mW and 500 mW versions, put sockets on my 3rd V4 board and see how much difference there is between the 3 other types relative to the already installed 400 mw version. Hopefully that will give us some definitive answers. Be Monday before I can order them so it will be a few days before any testing can be done.
Jim Sheldon, W0EB
Re: Simpler spur fix
That is 680nH or 68 followed by one 0 - uH would have been 684 marking IMHO - like resistors.
I measured them and they were exact 680nH.
In some places the discussion relating to 680uH is about relays.
While people are buying 680nH, please also buy 331 = 330nH (10 Nos) for replacing the 30MHz LP filter
which also helped. L1 is very sensitive to surroundings causes ringing when touched.
Raj
toggle quoted message
Show quoted text
I measured them and they were exact 680nH.
In some places the discussion relating to 680uH is about relays.
While people are buying 680nH, please also buy 331 = 330nH (10 Nos) for replacing the 30MHz LP filter
which also helped. L1 is very sensitive to surroundings causes ringing when touched.
Raj
At 14/10/2018, you wrote:
Am 14.10.2018 um 03:34 schrieb Joe Puma:This popped up on Amazon when I searched for 1210 680nhIn some postings are mentioned 680uH inductors in some 680nH. uH or nH?? I had a look at the picture in Raj's posting #60465 and read there 681K. This would mean 680uH 10%. Inductor values in nH should be marked with N according to standart.On Oct 12, 2018, at 11:27 PM, Raj vu2zap <rajendrakumargg@...> wrote:Been looking around for the 1210 680nh inductors and cannot find a source yet.
73 Matthias, DD7NT
Re: Harmonics and Relay Replacement
Raj,
I thought the same thing, but maybe, even using sockets, just for the experiment, I could get some relative comparisons between the types to see if any were better than others. I suspect the 500mw version, Arrow part# V23105A5503A201 will be the best because they have the lowest coil resistance, fewest turns on the coil. The only thing that worries me using that relay is it's current draw - I'm hoping it won't be too much for the switching transistors in the uBITX. The 400mW relays are working and switching OK but the additional current from the lower coil resistance may become a problem and I'm not sure yet.
I don't want to risk ruining the board by soldering and unsoldering the relays several times so planned on using sockets but ONLY on the one board I'm planning on setting up as a test station. I'll build it up on a board but use double shielded Teflon insulated COAX from the uBITX boards 2 pin connector to the BNC output and make all digital and audio wires twisted pair to the front panel jacks, encoder and switch. The construction will be open, no case but the uBITX board will be mounted on a 16 gauge aluminum plate to give a good underside ground plane and good low Z grounds for all connections.
I have some good, gold plated machined pin socket strips that are very low profile and will use those to create the sockets. Again, for these tests I will only look for which of the 4 relay types gives the best harmonic attenuation between types and then I will solder that set into a uBITX for the final results. Only way I know to test all 4 types without possibly ruining a good board from too much soldering/de-soldering of relays. A repaired trace would negate the original test results as it's characteristics would be different.
Hope people can understand what I'm trying to say here.
Jim
toggle quoted message
Show quoted text
I thought the same thing, but maybe, even using sockets, just for the experiment, I could get some relative comparisons between the types to see if any were better than others. I suspect the 500mw version, Arrow part# V23105A5503A201 will be the best because they have the lowest coil resistance, fewest turns on the coil. The only thing that worries me using that relay is it's current draw - I'm hoping it won't be too much for the switching transistors in the uBITX. The 400mW relays are working and switching OK but the additional current from the lower coil resistance may become a problem and I'm not sure yet.
I don't want to risk ruining the board by soldering and unsoldering the relays several times so planned on using sockets but ONLY on the one board I'm planning on setting up as a test station. I'll build it up on a board but use double shielded Teflon insulated COAX from the uBITX boards 2 pin connector to the BNC output and make all digital and audio wires twisted pair to the front panel jacks, encoder and switch. The construction will be open, no case but the uBITX board will be mounted on a 16 gauge aluminum plate to give a good underside ground plane and good low Z grounds for all connections.
I have some good, gold plated machined pin socket strips that are very low profile and will use those to create the sockets. Again, for these tests I will only look for which of the 4 relay types gives the best harmonic attenuation between types and then I will solder that set into a uBITX for the final results. Only way I know to test all 4 types without possibly ruining a good board from too much soldering/de-soldering of relays. A repaired trace would negate the original test results as it's characteristics would be different.
Hope people can understand what I'm trying to say here.
Jim
------ Original Message ------
From: "Raj vu2zap" <rajendrakumargg@...>
To: [email protected]
Sent: 10/14/2018 1:06:47 AM
Subject: Re: [BITX20] Harmonics and Relay Replacement
From: "Raj vu2zap" <rajendrakumargg@...>
To: [email protected]
Sent: 10/14/2018 1:06:47 AM
Subject: Re: [BITX20] Harmonics and Relay Replacement
Jim,
My take on this relay business is that both contacts are being inductively coupled.
Imagine the NC contacts on one side - it is a loop and will be inductive. The same goes
for the other pair on the other side..
By adding a socket we may not get the best rejection from Axicom relays. I have also
socketed KT1/2/3 .. the relays have arrived and I am at the farm.. so a week more
of suspense.
If someone with a SA like 815 can feed in the tracking gen through a 47 ohm resistor
to one NC contacts in/out and take the Analyser input from the other NC contact set
and then sweep say up to 100MHz, we get some enlightenment. I am eagerly waiting
to try for myself.
Raj
At 13/10/2018, you wrote:Looking at the differences between the original Hongfa relays -S (for sensitive) version in my uBITX boards and the Axicom relays Mike Doty and I installed in place of them, the Axicom had lower coil resistance in the 400 mW coils vs the 200 mW coils fot the Hongfa relays. That means fewer turns of wire in the Axicoms and subsequently less inductance. That may be a huge factor in the isolation between the two types. The coil resistance for the Axicom that matches the Hongfa in DC spec aldo has the exact same listed coil resistance.
I'm going to order 5 each of the 150mW, 200 mW and 500 mW versions, put sockets on my 3rd V4 board and see how much difference there is between the 3 other types relative to the already installed 400 mw version. Hopefully that will give us some definitive answers. Be Monday before I can order them so it will be a few days before any testing can be done.
Jim Sheldon, W0EB
Re: High Frequency Choke for Bitx40
David Wilcox K8WPE
¿ªÔÆÌåÓý
The learning module referenced is an excellent source for ALL electronics theory. ?Add it to your home page. ?This winter when it is too nasty to go outside and you are tired of making contacts you can sit by the fire and update your electronics knowledge.?
Thanks to DaveT.
Dave K8WPE
On Oct 13, 2018, at 7:11 PM, davedt1e@... wrote:
Here's my obligatory "I'm no expert, but.." statement.? ?I'm no expert but I bet what's being done here is an "LC" filter or "Inductance / Capacitance" filter.? Or perhaps an enhancement of the existing one.? This circuit is commonly used to smooth out ripples and other such nasties in A/C or varying D/C current.? The choke filters out higher frequencies above some certain value, and the capacitor allows lower frequencies that you want thru and smooths them out.
Here's a pretty well written overview.
Re: Simple spur fix
Lev, Any experiments on this ?
At 05/09/2018, you wrote:
toggle quoted message
Show quoted text
At 05/09/2018, you wrote:
Would that be a good solution to make the IF amplifier tuned? Like this? Also, change the transistors to BFS17P, this is more suited to RF.
73s de HA5OGL
On Wed, Sep 5, 2018 at 10:46 AM Raj vu2zap < rajendrakumargg@...> wrote:
- This fix reduced the spurs by up to 10 db?? and requires ONLY ONE part to be added.
- There is big change above 10MHz in the board. There is some improvement below also.
Re: Something not right 24V PA BITX40
Tim,
Looks like you 12V is not OK. Increase to 15V and see. I have run my boards on 15V with much better output.
If the power goes up and then settles back down, I suspect your 12V not sustaining current. I am not sure
how you are supplying power before and after boxing.. that should give you a clue.
Raj
toggle quoted message
Show quoted text
Looks like you 12V is not OK. Increase to 15V and see. I have run my boards on 15V with much better output.
If the power goes up and then settles back down, I suspect your 12V not sustaining current. I am not sure
how you are supplying power before and after boxing.. that should give you a clue.
Raj
At 11/10/2018, you wrote:
I have my BITX40 up and running. Just got on the air for the first time a month ago. Lots of FT8 contacts and a few other digital contacts. I just put it in a case with a switch for the PA power section.
I can run the PA with the 12 volts or switch to an external source. Before boxing it I was able 13 Watts on 24.5volts. Currently I only get 7 Watts on 24.5 volts.
On 12 volts I get 5.5 Watts with 1.2 amps draw with a loud hello and 97 mA idle
On 24.5 volts I get 7 Watts with 1.5 amp draw with a loud hello and 103 mA idle.
Did I break something or am I doing something wrong? Using Lipo batteries for the PA and they sit idle at 24.5 volts and drop to 24.1 during the transmit. I tried increasing the drive on RV136. Seems I might get more output momentary then it settles back down to 7 Watts.
Any thoughts are appreciated.