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Re: I'm really stuck! No Xmit Pwr.
#ubitx
¿ªÔÆÌåÓýChip?? It is possible to use your oscilloscope to trace signal flow, but the scope needs to have adequate bandwidth for the signal being viewed.? A diode detector (1N4148 diodes work fine for all but very low level testing) is faster and more convevient for transmit side signal tracing.?? Arv _-_ Sent from my Verizon, Samsung Galaxy smartphone -------- Original message -------- From: "Latham, Chip" <clatham@...> Date: 6/20/18 8:35 AM (GMT-07:00) Subject: Re: [BITX20] I'm really stuck! No Xmit Pwr. #ubitx I do have a digital storage o'scope... trying . Pay day is a ways off and I am tapped out so no more orders to the parts place this week. but have a wealth of junk just will take a bit.? I appreciate everything that everyone is suggesting. Thank you Frustrated Ham N5FJK Chip? |
Re: Understanding Spurious Emissions
¿ªÔÆÌåÓýMost who have performed detailed tests seem to indicate that unwanted spurs are a problem only if AF or RF drive levels are set too high.? On CW the uBITX does not use modulation and thus has low spurious output. Arv _-_ Sent from my Verizon, Samsung Galaxy smartphone -------- Original message -------- From: Howard Fidel <sonic1@...> Date: 6/20/18 8:36 AM (GMT-07:00) Subject: [BITX20] Understanding Spurious Emissions (d) For transmitters installed after January 1, 2003, the mean power of any spurious emission from a station transmitter or external RF power amplifier transmitting on a frequency below 30 MHz must be at least 43 dB below the mean power of the fundamental emission. For transmitters installed on or before January 1, 2003, the mean power of any spurious emission from a station transmitter or external RF power amplifier transmitting on a frequency below 30 MHz must not exceed 50 mW and must be at least 40 dB below the mean power of the fundamental emission. For a transmitter of mean power less than 5 W installed on or before January 1, 2003, the attenuation must be at least 30 dB. A transmitter built before April 15, 1977, or first marketed before January 1, 1978, is exempt from this requirement.? The first interesting thing about these regulations is that they are not consistent across time. If you have a transmitter that was installed before April 15, 1977 it is not even regulated for spurious emissions. Before 2003, the spurs were limited to 50 mW max and must be at least 40 dB below the carrier power. Today, the constraint is -43 dB below the carrier power. So if you have a 1 KW transmitter, you are allowed to have spurs that do not exceed 50 mW, hence the earlier 50 mW limit. To keep things in perspective, if your uBitx puts out 5 watts of power on 15 meters, 50 mW of energy would be only 20 dB down from your carrier.? So if you use your uBitx barefoot (i.e without a linear amp) although you may exceed the allowed spur amplitude on the 15 and 10 meter bands, your radiated power level will be so low that it is virtually impossible for it to interfere with other services, and that your radiated emissions maybe in line with what other ham operators are radiating legally. Also, I might add that these spurs are not consistent in amplitude? from unit to unit. I measured mine as being in compliance, but right at the -43 dB limit. Furthermore, the testing is done into a dummy load. When connected to an antenna, your SWR at the spur frequency is probably high, so you are radiating even less energy.? My personal take away from this is that although the uBitx may at times not be in technical compliance with the regulations, operating at frequencies above 21 MHz, it is in compliance with the intent of the law, which is to prevent interference with other services. You can help your uBitx stay in-compliance by not over driving your audio, and by only operating it barefoot above 21 MHz.? So, the bottom line is you should not use the uBitx above 21 MHz if you are concerned with the letter of the law, but you may use it if you are concerned with complying with the intent of the law. Howard |
Re: Output power
On Wed, Jun 20, 2018 at 08:36 am, ajparent1/KB1GMX wrote:
You need a load (10W) such as six 300 ohm 2 watt metal film resistors in parallelIf anyone is looking for a kit here what I have ? sure you could piece together the parts for a little less but I didn't have everything on hand. ? -- |
Re: uBITX Version 4 first attempt
#ubitx-help
#ubitx
I am reading this thread. I really have no comments except that there is no objective measurement or audio clip that i can comment upon. Hence let me make some general comments. As old timers will testify, i never recommend, leave alone ship a circuit that i havent built at least twice and operated them on air for at least three or four mornings. I did extensive on-air tests as well as distortion measurements on the new? audio amplifier before shipping it out. The thing that I have been unhappy about is that I had to reduce the overall gain. I took a decision to not revise the circuit too much but fix the excessive gain that can distort without the AGC. If we had the luxury of AGC, we could have lived with higher gain. The radio is now optimised to work well into 21 mhz. At 28 mhz, the gain is enough for headphone operations but speaker output will work only in a quite room.? I continue to use the v4 regularly with FT8 as well as local ragchew on 40 meters. I have asked production to ship me a latest batch board to test it out. This is just in case there has been a mistake in terms of change of component values. I will report. This back in a day.? - f On Wed, 20 Jun 2018, 20:54 Jack Purdum via Groups.Io, <jjpurdum=[email protected]> wrote:
|
Re: RF power chain mods and improvements..
On Wed, Jun 20, 2018 at 08:38 am, M Garza wrote:
2N5770I took a look at the datasheet.? It might be a good part to try.? I'd be curious to hear if they work for you. Hint if you go with 2n5109s due to their size its easier to put on on the top and the other on the bottom. Despite its oddities its an interesting radio to work with. Allison |
Re: RF power chain mods and improvements..
M Garza
I have to agree with Allison.? I tried KSP10s (TO-92)? and a KST10s? (SOT-23).? These are exactly the same as the MPSH10s.? Things went backwards.? They only dissipate 350mw.? The FT is higher but it doesn't compensate for the lack of power out.? I will be installing a BFR106 for Q90 and will try some 2N5770s for the pre-drivers.? I am just playing with what I have.? I will probably end up ordering some 2N5109s to put in as pre-drivers and drivers.? I don't know yet.? I am having too much fun playing around with this little radio. Marco - KG5PRT? On Wed, Jun 20, 2018, 10:21 AM ajparent1/KB1GMX <kb1gmx@...> wrote: Nick, |
Re: Output power
You don't need an Arduino to measure power.
You need a load (10W) such as six 300 ohm 2 watt metal film resistors in parallel and a 1n5711 diode to rectify the RF.? ? Look around the net as that is an easy build. Read the voltage with a voltmeter (analog or digital). I built mine a large fraction of a century ago small box, connector, load as described, and a diode with binding posts for connecting the meter.?? Calibration, the easy was is apply known DC voltages across the load and note the? DC meter reading after the diode.? Do this for many points and make a chart of? power in for voltage out. Calculate power in: The power is: DCin^2/50=? (DC applied voltage squared then divide by 50).? That works well enough to get to better than 5% accurate at least. No need to use a microprocessor unless you have time to burn. as then you need a opamp to linearize the diode and scale the input. Allison |
Re: uBITX Version 4 first attempt
#ubitx-help
#ubitx
I haven't assembled my v4 kit I received a few weeks ago yet, but have been reading and planning for an upcoming build and am really excited.? I was hesitant at first about ordering the kit as I recognized it wouldn't be the same as going out and buying a FT-817 or something similar, but the passion and activity around this project brought me in.? I'm guessing I will have a working radio at the end of assembly if I do everything right and it might put out some power everywhere, might have decent audio, but overall that isn't the goal for me.? The goal for me is to understand more about radio and eventually customize the uBitx into the radio I want to use.? I haven't seen excitement around building a piece of electronics since the late 90's early 2000's when I jumped in to the guitar tube amp building community and started out not really understanding anything and ended up being reasonably competent at building, repairing, and even designing some amps over time.? I hope to understand the radio side of the uBitx through experimenting with my build and this discussion group and hope to hack a little with the Arduino side as I have a little experience there as well.? It is really an elegant design and I kind of like the simplicity of using mostly the same transistor throughout the circuit in rf and audio.
BTW, I have a FT-817 as well and it doesn't work out of the box either.? You might turn it on and hit a local repeater on 2 or 440 with the stock antenna, but to work HF you have to figure out antennas, tuners, power supplies, interface cabling for digital modes, etc.? I have had a blast with that used FT-817 as well and it cost way more than the uBitx even though I purchased it used. |
Re: uBITX Version 4 first attempt
#ubitx-help
#ubitx
Jack Purdum
"...that it will be required by the builder to almost replace every component to make the rig work." Bullcrap, and you know it! "No one can expect a builder to rip out components and bodge the pcb to
get it to work. This is not a user friendly board as it is all surface
mounted and if you dont have good eye sight and the correct equipment
then it will end up as a bin job!!" More bullcrap. First, all 5 of mine worked "out of the box" and, add about three or four thousand more buyers who also have it working without mods, and I'm pretty sure you screwed something up. Second, I'm 75 with a sad excuse for eyesight, yet with a headset of magnifying lens, I've found that I can solder a 10-pin Si5351 chip the size of a match head onto a PCB. Have you even tried working with SMD parts? You knew before you bought the two rigs that they contained SMD parts and that many mods have been made. Sounds to me like you ignored your own research. Whose fault is that? "I paid good money for a Bitx 40 and a Ubitx V3 and both were received
damaged, a replacement Bitx was sent and that was also received damaged." Evidently you didn't learn your lesson on the first one and should have paid the DHL fee on the second. I've purchase 5 units and everyone of them arrived in good shape, and the US is farther away the the UK. As someone once said: "Insanity is doing the same thing over and over and expecting different results". Seems to me to be sort of a "fool-me-once" situation on your part. Jack, W8TEE
On Wednesday, June 20, 2018, 9:57:33 AM EDT, Ray Koster via Groups.Io <raykoster@...> wrote:
I think that Andy is correct in thinking why he should have to do all these mods to this kit!! I also have purchased and built several kits in the past and have never had to do the scale of modifications that are now required to get this kit to work correctly. It was never disclosed on the HF signals website that it will be required by the builder to almost replace every component to make the rig work and be legal on the air. Why are you Guy's sticking up for Farhan, when he does not come forward and hold his hands up and say that the kit should have never gone to market.If this was UK produced ,then Trading Standards would have closed HF Signals down long ago!!! No one can expect a builder to rip out components and bodge the pcb to get it to work. This is not a user friendly board as it is all surface mounted and if you dont have good eye sight and the correct equipment then it will end up as a bin job!! Also most builders do not have the correct test equipment to make tests to insure that after all these mod's, they are legal when on the air with this kit My biggest beef about all this is that HF Signals cannot deliver a kit to me that is not damaged in the post and please dont tell me I have pissed of the postman, My postman is a nice guy and so are the staff at the sorting office and India to the UK is a very long way I paid good money for a Bitx 40 and a Ubitx V3 and both were received damaged, a replacement Bitx was sent and that was also received damaged. When I pay good money, I expect to receive the goods in a usable state and then I do not expect to have to then remove and replace most of the components at my expense, and?probably?have to wait weeks for these new components to come in, just to get it to work correctly Firmware updates are acceptable as the nature of the code can led to bugs creeping in and this is a very easy thing to do and does not require butchery of the pcb Ray Koster G7BHQ |
Re: RF power chain mods and improvements..
Nick,
The biggest difference is the BFR106 has a FT of 5GHZ minimum and the MMBTh10 its 650 (typical). That is the starting point.? ?That should stand out for a application that requires a lot of gain at upper HF and VHF.? Actually I did try them (MPSH10 is the same part in TO92 plastic) for the predriver and driver, they sucked compared to the 2n2222A(to18). You can certainly try the other and likely it will help some. You are on your own.? Allison |
Re: uBITX Version 4 first attempt
#ubitx-help
#ubitx
RICHARD
¿ªÔÆÌåÓýMine works fine as advertised.? It¡¯s people like you that killed Heathkit and other inexpensive radios . The radio works fine and legal, ?if used properly.? If you don¡¯t like them go buy a Kenwood. I bought 2 of the radios and mine worked as advertised and arrived in the US mail with no damage. K6KWQ?? A ham for 55 years. ? Sent from for Windows 10 ? From: [email protected] <[email protected]> on behalf of Ray Koster via Groups.Io <raykoster@...>
Sent: Wednesday, June 20, 2018 6:57:27 AM To: [email protected] Subject: Re: [BITX20] uBITX Version 4 first attempt #ubitx-help #ubitx ?
I think that Andy is correct in thinking why he should have to do all these mods to this kit!! I also have purchased and built several kits in the past and have never had to do the scale of modifications that are now required to get this kit to work correctly.
It was never disclosed on the HF signals website that it will be required by the builder to almost replace every component to make the rig work and be legal on the air.
Why are you Guy's sticking up for Farhan, when he does not come forward and hold his hands up and say that the kit should have never gone to market.If this was UK produced ,then Trading Standards would have closed HF Signals down long ago!!! No one can expect a builder to rip out components and bodge the pcb to get it to work. This is not a user friendly board as it is all surface mounted and if you dont have good eye sight and the correct equipment then it will end up as a bin job!! Also most builders do not have the correct test equipment to make tests to insure that after all these mod's, they are legal when on the air with this kit My biggest beef about all this is that HF Signals cannot deliver a kit to me that is not damaged in the post and please dont tell me I have pissed of the postman, My postman is a nice guy and so are the staff at the sorting office and India to the UK is a very long way I paid good money for a Bitx 40 and a Ubitx V3 and both were received damaged, a replacement Bitx was sent and that was also received damaged. When I pay good money, I expect to receive the goods in a usable state and then I do not expect to have to then remove and replace most of the components at my expense, and?probably?have to wait weeks for these new components to come in, just to get it to work correctly Firmware updates are acceptable as the nature of the code can led to bugs creeping in and this is a very easy thing to do and does not require butchery of the pcb Ray Koster G7BHQ |
Re: RF power chain mods and improvements..
Because the part in the to92 package is not the same especially the pn2222.
Its not blind do it its the result of testing.? ?There are two parts that use the? same die, 2n22222(a) and 2n2219(a).? the differnce between them is power dissipation of the 2n2219 is higher (TO5 case). The TO92 part cannot stand the same peak current and also has a lower power dissipation. Some are not even made with the same process.? Changing process invokes a change in performance. Keep in mind its not the BEST choice but by actual testing in several units a better one. Allison |
Re: uBITX Version 4 first attempt
#ubitx-help
#ubitx
Brian L. Davis
There are literally thousands of these radios in the hands of users and only a very, very few have had any problems.
They work as advertised if built in a reasonable fashion, something Farhan has no control over. As far as delivery, I am in Oklahoma, USA and mine arrived in pristine condition as have nearly all others. You DO NOT have to replace any components. You DO NOT have to rip out components and bodge the pcb to get it to work. You DO NOT have to make any modifications to make it work. If you have a postal delivery problem, complain to them, Farhan did not damage your mail. This is a very, very inexpensive radio and you can modify it if you want but YOU DON'T HAVE TO. If you would read the posts here you would find that you are nearly alone in your complaints and criticisms! There? is an old saying that some people would complain about being hung with a new rope. I believe that would be appropriate in this instance. |
Understanding Spurious Emissions
There have been a few threads discussing how the uBitx has spurs that may exceed the spur amplitude allowed by law. Ham radio is regulated by Part 97 of the FCC regulations. The allowed spur amplitude for frequencies below 30 MHz is in section 307. I have reproduced paragraph D below:
(d) For transmitters installed after January 1, 2003, the mean power of any spurious emission from a station transmitter or external RF power amplifier transmitting on a frequency below 30 MHz must be at least 43 dB below the mean power of the fundamental emission. For transmitters installed on or before January 1, 2003, the mean power of any spurious emission from a station transmitter or external RF power amplifier transmitting on a frequency below 30 MHz must not exceed 50 mW and must be at least 40 dB below the mean power of the fundamental emission. For a transmitter of mean power less than 5 W installed on or before January 1, 2003, the attenuation must be at least 30 dB. A transmitter built before April 15, 1977, or first marketed before January 1, 1978, is exempt from this requirement.? The first interesting thing about these regulations is that they are not consistent across time. If you have a transmitter that was installed before April 15, 1977 it is not even regulated for spurious emissions. Before 2003, the spurs were limited to 50 mW max and must be at least 40 dB below the carrier power. Today, the constraint is -43 dB below the carrier power. So if you have a 1 KW transmitter, you are allowed to have spurs that do not exceed 50 mW, hence the earlier 50 mW limit. To keep things in perspective, if your uBitx puts out 5 watts of power on 15 meters, 50 mW of energy would be only 20 dB down from your carrier.? So if you use your uBitx barefoot (i.e without a linear amp) although you may exceed the allowed spur amplitude on the 15 and 10 meter bands, your radiated power level will be so low that it is virtually impossible for it to interfere with other services, and that your radiated emissions maybe in line with what other ham operators are radiating legally. Also, I might add that these spurs are not consistent in amplitude? from unit to unit. I measured mine as being in compliance, but right at the -43 dB limit. Furthermore, the testing is done into a dummy load. When connected to an antenna, your SWR at the spur frequency is probably high, so you are radiating even less energy.? My personal take away from this is that although the uBitx may at times not be in technical compliance with the regulations, operating at frequencies above 21 MHz, it is in compliance with the intent of the law, which is to prevent interference with other services. You can help your uBitx stay in-compliance by not over driving your audio, and by only operating it barefoot above 21 MHz.? So, the bottom line is you should not use the uBitx above 21 MHz if you are concerned with the letter of the law, but you may use it if you are concerned with complying with the intent of the law. Howard |
Re: I'm really stuck! No Xmit Pwr.
#ubitx
I will see if I can come up with a?germanium diode.?
I do have a digital storage o'scope... trying . Pay day is a ways off and I am tapped out so no more orders to the parts place this week. but have a wealth of junk just will take a bit.? I appreciate everything that everyone is suggesting. Thank you Frustrated Ham N5FJK Chip? |
Re: uBITX Version 4 first attempt
#ubitx-help
#ubitx
¿ªÔÆÌåÓýGroup, I have 5 bitX transceivers, 2 Hendricks and 3 from Ashar. I really like my units (allof them). I have to admit that I did have problems with my bitX40 but that was my fault. My meter was defective and when I went to adjust the bias my meter read zero so I cranked up the drive and burned out my final. I fixed it and all is well. I have to admit that the audio can be improved by adding an agc circuit but that is not really necessary if you just adjust the volume control to suit the strong or weak signal coming in. My last purchase was the original uBitX and this time I did nothing to it. Yes, it can be improved but I haven't done that yet. I am having too much fun using it. I am in Iowa and my first contact was in California and since then I have logged about 15 States. On 40 I spent 10 minutes trying to get through a pile up of stations calling a station in Spain. I think that I could have logged him if I only had a little more time, he was 20 over on 40. I say all this just to prove one point, this transceiver works out of the box without any mods and all you have to supply is power and a case. If I'm getting over 5 watts, I'm happy. If I need more power I have my 100 watt rig and if that doesn't do it I use my Dentron amp for 1600 watts out. Its more fun doing it with 5 watts. Ashar has done a great job getting this unit out to us and we shouldn't complain about his excellent work. Ive seen it all (ham for 64 years) Ed W0OIC On 6/20/2018 7:49 AM, Jack Purdum via
Groups.Io wrote:
|
Re: uBITX Version 4 first attempt
#ubitx-help
#ubitx
¿ªÔÆÌåÓýRay G7BHQ None of those mods are required for the transceiver to operate properly. The audio was not an issue until someone who did not understand push-pull follower circuit biasing proclaimed that the circuit would never work. Arv k7hkl _-_ Sent from my Verizon, Samsung Galaxy smartphone -------- Original message -------- From: "Ray Koster via Groups.Io" <raykoster@...> Date: 6/20/18 7:57 AM (GMT-07:00) Subject: Re: [BITX20] uBITX Version 4 first attempt #ubitx-help #ubitx Why are you Guy's sticking up for Farhan, when he does not come forward and hold his hands up and say that the kit should have never gone to market.If this was UK produced ,then Trading Standards would have closed HF Signals down long ago!!! No one can expect a builder to rip out components and bodge the pcb to get it to work. This is not a user friendly board as it is all surface mounted and if you dont have good eye sight and the correct equipment then it will end up as a bin job!! Also most builders do not have the correct test equipment to make tests to insure that after all these mod's, they are legal when on the air with this kit My biggest beef about all this is that HF Signals cannot deliver a kit to me that is not damaged in the post and please dont tell me I have pissed of the postman, My postman is a nice guy and so are the staff at the sorting office and India to the UK is a very long way I paid good money for a Bitx 40 and a Ubitx V3 and both were received damaged, a replacement Bitx was sent and that was also received damaged. When I pay good money, I expect to receive the goods in a usable state and then I do not expect to have to then remove and replace most of the components at my expense, and?probably?have to wait weeks for these new components to come in, just to get it to work correctly Firmware updates are acceptable as the nature of the code can led to bugs creeping in and this is a very easy thing to do and does not require butchery of the pcb Ray Koster G7BHQ |
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