No, you won't face any surprises.
For the same reason I used a 4K7 /A (linear) I had with dual pole power switch.
Really a robust pot from another era.
Naturally, the AF IC was toasted, but this has nothing to do with the pot.
Replaced it with an equivalent type and works ok since.
I also hooked up an RCA terminated audio cable at the extremes of this pot in order to connect my ADC sound converter at a fixed audio level for digital work. The ADC is high impedance input, but none the less it is in parallel with the 4,7KOhms of the pot.
No loading problem to the preceding stages, Cleaner audio signal is a bonus.
73 Nikos
|
|
|
Re: The new uBITX boards are here
Hi,
There are references to 'New code' by various members of this group but the links all seem just descriptive. Can't see any 'Download Ver_xx here' on the sites.
I have mine built and tested as standard with the WX chip, but audio sounds good on earphones.
?
Peter Paul Fox G8HAV
Mid-Cheshire Amateur Radio Society
5 Llandovery Close
Winsford
Cheshire CW7 1NA?
Group Controller
Dane Valley?RAYNET?
Tel: 01606553401 (H)
Tel: 07919315547 (M)
toggle quoted message
Show quoted text
Peeps,?
HF Signals has rolled out the new (r4) version of the PCBs. Here are the changes:
1. A new, low distortion audio amplifier made from discrete transistors. This is one is optimized for head-phones and connecting to PCs for digital modes. It does work with the small speakers as well. Builders with the earlier versions can try this audio
amplifier as an outboard amplifier.
2. The audio thump issue during T/R switching has been fixed.
3. At 28 Mhz, the output is about 4 watts. (this involves a single capacitor change from the earlier PCB).
4. I have included some 'jump' points to add interesting stuff like CW filters to the board. There are a large number of test points to help you debug and understand the board.?
All in all, the changes are 'backward compatible' . That is, you can hack these changes to the previous boards to get in the new functionality. I have updated the circuit diargrams on
. The earlier board's circuit diagram has moved to?
The bad news is that we had to bump up the price of the board by 20 dollars. We fought long and hard to keep the price down. My personal ambition was to keep the price inside (or at) $100. This is price rise has to do with three things : The recent changes
in the Indian import duty and sales tax; Our own increasing costs to preorder the parts. Lastly, we also increased our payout to those who wind the coils, assemble and test the boards. They were working at the same rate for the last two years. It was about
time.?
The new boards cost $129 USD with shipping. $139 USB with DHL option.?
The good news is that from now on, these boards will be available on order. The waiting queue is gone.
On a personal note, I am happy with the new audio. It is so much sweeter and cleaner on the headphones.? Far less fatigue after hours of CW work. I am also using the FT8 extensively, I have bagged almost twenty countries, testing the new firmware.
- f
|
Re: RF power chain mods and improvements..
Sorry for the late reply (was traveling).? The MPSH10¡¯s give a very flat profile up to about 60 MHz and beyond.? I¡¯m struggling with the pre-driver(s) choice at the moment¡ Q92,Q93, Q96, Q97.? I¡¯m waiting to hear how the 2N5109¡¯s pan out.? They have a favorable fte for this service, and can make enough power to drive the RD parts in the PA fine.? I¡¯m spending some time on the interstage transformer (T10) because I don¡¯t believe it¡¯s designed properly.? I replaced T11 with a BN61-002¡ a little overkill but extremely efficient.
?
?
Dr. William J. Schmidt - K9HZ
?
From: [email protected] [mailto:[email protected]] On Behalf Of Nick VK4PLN
Sent: Thursday, May 24, 2018 9:08 PM
To: [email protected]
Subject: Re: [BITX20] RF power chain mods and improvements..
?
Hi Dr William,
How is your radio performing with the mpsh10 and rd16hff1 ?
73.
?
|
Glad it went smoothly, and worked so well. I still have thousands
of parts left, so I probably can give the parts out for a few
years.
Howard
On 5/26/2018 2:07 PM, RowlandA wrote:
toggle quoted message
Show quoted text
I did the mod
(thanks Howard for the parts!) and here's what I got:
80M? 11W before 13W after
40M? 11W? ? ? ? ? ? ?14W
20M? 7.8W? ? ? ? ? ? 11W
17M? 4.7W? ? ? ? ? ? 6.8W
15M? 4.0W? ? ? ? ? ? 5.6W
12M? 3.0W? ? ? ? ? ? 5W
10M? 2.5W? ? ? ? ? ? 4.3W
My test was using the Tune button in WSJT-X, and a dummy load.
I applied the parts the same way the Nigel G4ZAL did, including
the tee-pee'd inductor to R86.? This was my first excursion into
SMD soldering; I used a headband with a drop-down magnifier and
LED light, and seeing the parts was easy.? Actually the whole
process was a lot easier than I expected.??
73,
Rowland K4XD
|
Re: The new uBITX boards are here
I just picked one up thanks, wanted a second ubitx anyway.
Still the best value @129.00 absolutely.
Thank you!!
Laurence
toggle quoted message
Show quoted text
On Sat, May 26, 2018 at 3:19 PM, Ashhar Farhan <farhanbox@...> wrote: Peeps,
HF Signals has rolled out the new (r4) version of the PCBs. Here are the
changes:
1. A new, low distortion audio amplifier made from discrete transistors.
This is one is optimized for head-phones and connecting to PCs for digital
modes. It does work with the small speakers as well. Builders with the
earlier versions can try this audio amplifier as an outboard amplifier.
2. The audio thump issue during T/R switching has been fixed.
3. At 28 Mhz, the output is about 4 watts. (this involves a single capacitor
change from the earlier PCB).
4. I have included some 'jump' points to add interesting stuff like CW
filters to the board. There are a large number of test points to help you
debug and understand the board.
All in all, the changes are 'backward compatible' . That is, you can hack
these changes to the previous boards to get in the new functionality. I have
updated the circuit diargrams on www.hfsignals.com. The earlier board's
circuit diagram has moved to
The bad news is that we had to bump up the price of the board by 20 dollars.
We fought long and hard to keep the price down. My personal ambition was to
keep the price inside (or at) $100. This is price rise has to do with three
things : The recent changes in the Indian import duty and sales tax; Our own
increasing costs to preorder the parts. Lastly, we also increased our payout
to those who wind the coils, assemble and test the boards. They were working
at the same rate for the last two years. It was about time.
The new boards cost $129 USD with shipping. $139 USB with DHL option.
The good news is that from now on, these boards will be available on order.
The waiting queue is gone.
On a personal note, I am happy with the new audio. It is so much sweeter and
cleaner on the headphones. Far less fatigue after hours of CW work. I am
also using the FT8 extensively, I have bagged almost twenty countries,
testing the new firmware.
- f
|
Re: The new uBITX boards are here
Ashhar, I will be buying that new one ?soon. i have a recent one that i built and i love it. for 120- 140 dollars, you?can't touch another allbander like this in that price range,. you are?truly an inspiration to all Ham operators out here. Yes you can modify ,add, or just leave it stock. the design is beautiful .shows what can be done with minimal parts ?. You and your radio should be an example to all ?to renew the amateur radio community as a whole.
73s
David
ka9koj ?
On Saturday, May 26, 2018 3:19 PM, Ashhar Farhan <farhanbox@...> wrote:
Peeps,?
HF Signals has rolled out the new (r4) version of the PCBs. Here are the changes:
1. A new, low distortion audio amplifier made from discrete transistors. This is one is optimized for head-phones and connecting to PCs for digital modes. It does work with the small speakers as well. Builders with the earlier versions can try this audio amplifier as an outboard amplifier. 2. The audio thump issue during T/R switching has been fixed. 3. At 28 Mhz, the output is about 4 watts. (this involves a single capacitor change from the earlier PCB). 4. I have included some 'jump' points to add interesting stuff like CW filters to the board. There are a large number of test points to help you debug and understand the board.?
All in all, the changes are 'backward compatible' . That is, you can hack these changes to the previous boards to get in the new functionality. I have updated the circuit diargrams on . The earlier board's circuit diagram has moved to?
The bad news is that we had to bump up the price of the board by 20 dollars. We fought long and hard to keep the price down. My personal ambition was to keep the price inside (or at) $100. This is price rise has to do with three things : The recent changes in the Indian import duty and sales tax; Our own increasing costs to preorder the parts. Lastly, we also increased our payout to those who wind the coils, assemble and test the boards. They were working at the same rate for the last two years. It was about time.?
The new boards cost $129 USD with shipping. $139 USB with DHL option.?
The good news is that from now on, these boards will be available on order. The waiting queue is gone.
On a personal note, I am happy with the new audio. It is so much sweeter and cleaner on the headphones.? Far less fatigue after hours of CW work. I am also using the FT8 extensively, I have bagged almost twenty countries, testing the new firmware.
- f
|
Ha this is golden. You managed to dig a hole for yourself, fall in and then dig yourself out. I wish I was so skilled.
73
Joe
KD2NFC
toggle quoted message
Show quoted text
On May 26, 2018, at 3:18 PM, Vince Vielhaber <vev@...> wrote:
Yep. If it ain't broke, keep fixin it till it is broke.
Vince - K8ZW.
On 05/26/2018 11:17 AM, w1eat via Groups.Io wrote:
Well, I got my uBITX working just fine for me and decided it was a
keeper, so I ordered some TDA2822 spares on Ebay and they came a couple
of days ago, maked with the dreaded "WX". The part which came in the
socket on my board was not marked "WX" and gave me no trouble, but I
just couldn't help wondering if those spares were OK or not. So, I
replaced the known good, problem free part with one of the spares.
No problems. Every thing sounded fine and there was no loud pop or
acrid magic smoke. Great. I'm ready for trouble. Using my trusty chip
puller I removed the "WX" part and put the known good, problem free,
original IC back in the socket, facing the right way, all the legs in
their correct holes, and turned on the power.
In 3 seconds or so there was a loud pop and acrid magic smoke escaped
into the room. Somehow, the "WX" part managed to teach the known good,
problem free part how to be a bad boy, or maybe it just booby-trapped
the circuit somehow.
But there is more. I tried to key the transmitter, which has nothing to
do with the TDA2822 audio amp, and there was a single blip and then all
quiet. No TX voltage, but the RX voltage was fine. Thankfully, I'm
retired and I was able to spend many hours removing parts, testing and
replacing them. I traced out all the circuit I could and found one bad
solder joint of my own doing. I removed the IRF510 finals and the TX
voltage returned, so something is sick in the PA. I built an outboard
LM380 audio amp and wired it in using the TDA2822 solder pads. Nothing
heard, so I removed all the old AF amp parts from the board and cut some
traces to isolate the AF amp wiring. Attaching the LM380 amp
differently, the receiver came to life and the TX voltage returned. I
jumpered the TX driver output to the low pass filters and isolated the
PA wiring, giving me 1.1 watts out. FWIW, the output is about 1.1 from
160 thru 10m.
So, now I have a QRPp rig, some solder burns and an unproved theory that
the current surge that popped the IC also fried or shorted a land on PA
part of the board that I haven't found yet. I also have a renewed
appreciation for the LM380 because the audio is now much cleaner and CW
sounds more "bell like". If I can get the PA back into action I will be
ahead of where i was when the magic smoke escaped.
Tom W1EAT --
Michigan VHF Corp.
|
Re: The new uBITX boards are here
Ashhar,
thank you for the new board..removing the audio thump and increasing the output at 28Mhz are great...including breakout points for additional items (like my collection of CW filters) is excellent
again, a great job, I'll be ordering one...I'll add a 20x4 Parallel LCD display!
Bill Franzwa K6SIK
On Saturday, May 26, 2018 12:19 PM, Ashhar Farhan <farhanbox@...> wrote:
Peeps,?
HF Signals has rolled out the new (r4) version of the PCBs. Here are the changes:
1. A new, low distortion audio amplifier made from discrete transistors. This is one is optimized for head-phones and connecting to PCs for digital modes. It does work with the small speakers as well. Builders with the earlier versions can try this audio amplifier as an outboard amplifier. 2. The audio thump issue during T/R switching has been fixed. 3. At 28 Mhz, the output is about 4 watts. (this involves a single capacitor change from the earlier PCB). 4. I have included some 'jump' points to add interesting stuff like CW filters to the board. There are a large number of test points to help you debug and understand the board.?
All in all, the changes are 'backward compatible' . That is, you can hack these changes to the previous boards to get in the new functionality. I have updated the circuit diargrams on . The earlier board's circuit diagram has moved to?
The bad news is that we had to bump up the price of the board by 20 dollars. We fought long and hard to keep the price down. My personal ambition was to keep the price inside (or at) $100. This is price rise has to do with three things : The recent changes in the Indian import duty and sales tax; Our own increasing costs to preorder the parts. Lastly, we also increased our payout to those who wind the coils, assemble and test the boards. They were working at the same rate for the last two years. It was about time.?
The new boards cost $129 USD with shipping. $139 USB with DHL option.?
The good news is that from now on, these boards will be available on order. The waiting queue is gone.
On a personal note, I am happy with the new audio. It is so much sweeter and cleaner on the headphones.? Far less fatigue after hours of CW work. I am also using the FT8 extensively, I have bagged almost twenty countries, testing the new firmware.
- f
|
Tom, great troubleshooting. probably shorted fet ?outputs if the tx voltage returned after removing them.You could just build an outboard rf amp using the drive level from the board after the filters. I m thinking of doing that later on this winter. only reason is those particular fets are nice but in other qrp rig kits i have bought ,they have a high failure rate do to the bias settings.and they are quick to pop if u see the control too much.the voltage had to be set at such and such point and u would have plenty of output. i was using a fluke meter and the circuit voltage started jumping around. finally i replaced them with another type of fet and it stabilized permanently.ohhh the early days of using tube finals  ?.you could drive those boogers until the cows came home. But really i would stock up on the fets.there are some fellows here on the fourm that has replace these with other fets.u might try checking their posts.
good hunting Tom
73s
ka9koj ?
On Saturday, May 26, 2018 11:17 AM, w1eat via Groups.Io <w1eat@...> wrote:
Well, I got my uBITX working just fine for me and decided it was a keeper, so I ordered some TDA2822 spares on Ebay and they came a couple of days ago, maked with the dreaded "WX". ?The part which came in the socket on my board was not marked "WX" and gave me no trouble, but I just couldn't help wondering if those spares were OK or not. So, I replaced the known good, problem free part with one of the spares.
No problems. ?Every thing sounded fine and there was no loud pop or acrid magic smoke. ?Great. ?I'm ready for trouble. ?Using my trusty chip puller I removed the "WX" part and put the known good, problem free, original IC back in the socket, facing the right way, all the legs in their correct holes, and turned on the power.
In 3 seconds or so there was a loud pop and acrid magic smoke escaped into the room. ?Somehow, the "WX" part managed to teach the?known good, problem free part how to be a bad boy, or maybe it just booby-trapped the circuit somehow.
But there is more. ?I tried to key the transmitter, which has nothing to do with the TDA2822 audio amp, and there was a single blip and then all quiet. ?No TX voltage, but the RX voltage was fine. ?Thankfully, I'm retired and I was able to spend many hours removing parts, testing and replacing them. ?I traced out all the circuit I could and found one bad solder joint of my own doing. ?I removed the IRF510 finals and the TX voltage returned, so something is sick in the PA. ?I built an outboard LM380 audio amp and wired it in using the TDA2822 solder pads. ?Nothing heard, so I removed all the old AF amp parts from the board and cut some traces to isolate ?the AF amp wiring. ?Attaching the LM380 amp differently, the receiver came to life and the TX voltage returned. ?I jumpered the TX driver output to the low pass filters and isolated the PA wiring, giving me 1.1 watts out. ?FWIW, the output is about 1.1 from 160 thru 10m.
So, now I have a QRPp rig, some solder burns and an unproved theory that the current surge that popped the IC also fried or shorted a land on PA part of the board that I haven't found yet. ?I also have a renewed appreciation for the LM380 because the audio is now much cleaner and CW sounds more "bell like". ?If I can get the PA back into action I will be ahead of where i was when the magic smoke escaped.
Tom W1EAT
|
I was planning on doing that when my uB showed up, but by the time it did the concensus was the WX had a lower max voltage. I was thinking it might have been a voltage spike doing it at power up since most folks were reporting fire and brimstone when they turned it on.
Vince.
toggle quoted message
Show quoted text
On 05/26/2018 12:25 PM, Arv Evans wrote: It might be interesting if someone would work up a test jig for
evaluating and stress-testing the
"WX" series of amplifier chips. Could be revealing to see just what the
failure mode really is.
Arv
_._
On Sat, May 26, 2018 at 10:22 AM Mike aka KC2WVB
<rb5363@... <mailto:rb5363@...>> wrote:
Nice problem solving. Too bad it had to happen.
On Sat, May 26, 2018, 11:17 AM w1eat via Groups.Io
<w1eat@... <mailto:[email protected]>> wrote:
Well, I got my uBITX working just fine for me and decided it was
a keeper, so I ordered some TDA2822 spares on Ebay and they came
a couple of days ago, maked with the dreaded "WX". The part
which came in the socket on my board was not marked "WX" and
gave me no trouble, but I just couldn't help wondering if those
spares were OK or not. So, I replaced the known good, problem
free part with one of the spares.
No problems. Every thing sounded fine and there was no loud pop
or acrid magic smoke. Great. I'm ready for trouble. Using my
trusty chip puller I removed the "WX" part and put the known
good, problem free, original IC back in the socket, facing the
right way, all the legs in their correct holes, and turned on
the power.
In 3 seconds or so there was a loud pop and acrid magic smoke
escaped into the room. Somehow, the "WX" part managed to teach
the known good, problem free part how to be a bad boy, or maybe
it just booby-trapped the circuit somehow.
But there is more. I tried to key the transmitter, which has
nothing to do with the TDA2822 audio amp, and there was a single
blip and then all quiet. No TX voltage, but the RX voltage was
fine. Thankfully, I'm retired and I was able to spend many
hours removing parts, testing and replacing them. I traced out
all the circuit I could and found one bad solder joint of my own
doing. I removed the IRF510 finals and the TX voltage returned,
so something is sick in the PA. I built an outboard LM380 audio
amp and wired it in using the TDA2822 solder pads. Nothing
heard, so I removed all the old AF amp parts from the board and
cut some traces to isolate the AF amp wiring. Attaching the
LM380 amp differently, the receiver came to life and the TX
voltage returned. I jumpered the TX driver output to the low
pass filters and isolated the PA wiring, giving me 1.1 watts
out. FWIW, the output is about 1.1 from 160 thru 10m.
So, now I have a QRPp rig, some solder burns and an unproved
theory that the current surge that popped the IC also fried or
shorted a land on PA part of the board that I haven't found
yet. I also have a renewed appreciation for the LM380 because
the audio is now much cleaner and CW sounds more "bell like".
If I can get the PA back into action I will be ahead of where i
was when the magic smoke escaped.
Tom W1EAT
--
Michigan VHF Corp.
|
The new uBITX boards are here
Peeps,?
HF Signals has rolled out the new (r4) version of the PCBs. Here are the changes:
1. A new, low distortion audio amplifier made from discrete transistors. This is one is optimized for head-phones and connecting to PCs for digital modes. It does work with the small speakers as well. Builders with the earlier versions can try this audio amplifier as an outboard amplifier. 2. The audio thump issue during T/R switching has been fixed. 3. At 28 Mhz, the output is about 4 watts. (this involves a single capacitor change from the earlier PCB). 4. I have included some 'jump' points to add interesting stuff like CW filters to the board. There are a large number of test points to help you debug and understand the board.?
All in all, the changes are 'backward compatible' . That is, you can hack these changes to the previous boards to get in the new functionality. I have updated the circuit diargrams on . The earlier board's circuit diagram has moved to?
The bad news is that we had to bump up the price of the board by 20 dollars. We fought long and hard to keep the price down. My personal ambition was to keep the price inside (or at) $100. This is price rise has to do with three things : The recent changes in the Indian import duty and sales tax; Our own increasing costs to preorder the parts. Lastly, we also increased our payout to those who wind the coils, assemble and test the boards. They were working at the same rate for the last two years. It was about time.?
The new boards cost $129 USD with shipping. $139 USB with DHL option.?
The good news is that from now on, these boards will be available on order. The waiting queue is gone.
On a personal note, I am happy with the new audio. It is so much sweeter and cleaner on the headphones.? Far less fatigue after hours of CW work. I am also using the FT8 extensively, I have bagged almost twenty countries, testing the new firmware.
- f
|
Yep. If it ain't broke, keep fixin it till it is broke.
Vince - K8ZW.
toggle quoted message
Show quoted text
On 05/26/2018 11:17 AM, w1eat via Groups.Io wrote: Well, I got my uBITX working just fine for me and decided it was a
keeper, so I ordered some TDA2822 spares on Ebay and they came a couple
of days ago, maked with the dreaded "WX". The part which came in the
socket on my board was not marked "WX" and gave me no trouble, but I
just couldn't help wondering if those spares were OK or not. So, I
replaced the known good, problem free part with one of the spares.
No problems. Every thing sounded fine and there was no loud pop or
acrid magic smoke. Great. I'm ready for trouble. Using my trusty chip
puller I removed the "WX" part and put the known good, problem free,
original IC back in the socket, facing the right way, all the legs in
their correct holes, and turned on the power.
In 3 seconds or so there was a loud pop and acrid magic smoke escaped
into the room. Somehow, the "WX" part managed to teach the known good,
problem free part how to be a bad boy, or maybe it just booby-trapped
the circuit somehow.
But there is more. I tried to key the transmitter, which has nothing to
do with the TDA2822 audio amp, and there was a single blip and then all
quiet. No TX voltage, but the RX voltage was fine. Thankfully, I'm
retired and I was able to spend many hours removing parts, testing and
replacing them. I traced out all the circuit I could and found one bad
solder joint of my own doing. I removed the IRF510 finals and the TX
voltage returned, so something is sick in the PA. I built an outboard
LM380 audio amp and wired it in using the TDA2822 solder pads. Nothing
heard, so I removed all the old AF amp parts from the board and cut some
traces to isolate the AF amp wiring. Attaching the LM380 amp
differently, the receiver came to life and the TX voltage returned. I
jumpered the TX driver output to the low pass filters and isolated the
PA wiring, giving me 1.1 watts out. FWIW, the output is about 1.1 from
160 thru 10m.
So, now I have a QRPp rig, some solder burns and an unproved theory that
the current surge that popped the IC also fried or shorted a land on PA
part of the board that I haven't found yet. I also have a renewed
appreciation for the LM380 because the audio is now much cleaner and CW
sounds more "bell like". If I can get the PA back into action I will be
ahead of where i was when the magic smoke escaped.
Tom W1EAT
--
Michigan VHF Corp.
|
Sorry for not making it clear. I can upload to it by usb just like arduino. Now I need to compile some larger programs other than blink to make sure all is working. In the past I had problems with error in EEPROM ?when compiling ?I found some very new changes by Roger Clark and have them downloaded to give them a try . ?Thanks for the help and have a great and safe vacation .?
73's ?kn4ud ?
--
Allen ?Merrell
|
Re: uBITX Firmware CEC Version 1.08 Release
#ubitx
Ivo,
You need to look at the links Dr. Ian gives on his blog or download the manual.
|
I did the mod (thanks Howard for the parts!) and here's what I got:
80M? 11W before 13W after
40M? 11W? ? ? ? ? ? ?14W
20M? 7.8W? ? ? ? ? ? 11W
17M? 4.7W? ? ? ? ? ? 6.8W
15M? 4.0W? ? ? ? ? ? 5.6W
12M? 3.0W? ? ? ? ? ? 5W
10M? 2.5W? ? ? ? ? ? 4.3W
My test was using the Tune button in WSJT-X, and a dummy load.
I applied the parts the same way the Nigel G4ZAL did, including the tee-pee'd inductor to R86.? This was my first excursion into SMD soldering; I used a headband with a drop-down magnifier and LED light, and seeing the parts was easy.? Actually the whole process was a lot easier than I expected.??
73,
Rowland K4XD
|
Allen,
Please clarify "working OK just on USB"
|
Harbor Freight once again has the small Apache case on sale for $10, versus $15. They also have a special 25% off coupon if you buy something on Monday, May 28th. The case is virtually waterproof and very sturdy and would make a good case for any small project that might be used portable.
Jack, W8TEE
|
Re: 2 meter bitx possible?
It is BFG591 transistor. Check out hmc482 and bga612 mmics. = f
On Sat, 26 May 2018, 19:52 David Arthur, < mumrah@...> wrote: I'm also really curious about an inexpensive VHF/UHF MMIC. Searching around " BGA" takes me to NXP which has a wide selection of parts, but?no hits for?BGA591
-David
On Fri, May 25, 2018 at 3:34 PM Jerry Gaffke via Groups.Io <jgaffke= [email protected]> wrote: No hits for BGA591, can you give a link?
In some other forum, I recall a conversation between Ashhar and Allison regarding low noise mmic's for a VHF receiver front end.
Can't find it anymore.? Allison had a favorite, quite cheap, extremely low noise figure.
What was that part?
Jerry
On Fri, May 25, 2018 at 11:36 am, Ashhar Farhan wrote:
As an architecture, the ubitx is quite suitable upto 432 MHz. The changes needed would be as follows:
?
1. The front-end mixer would have to be an ADE-1 or and SBL-1. The current tranformers and BAT54s would cut it.
2. We will need a good band pass filter. Above 146 Mhz, stripline/coax filters are more likely candidates.
3. The LNA and power chain will need MMICs. they are cheap and easily ordered from . A pair of BGA591 can easily provide the obligatory 5 watts.
?
- f
--
David K4DBZ
Unofficial bitx chatroom:?
|
Re: ND6T AGC implementation for uBIT-X
Sorry phone replaced Kees with Lee's Thank you for your prompt reply
Sent from my Samsung Galaxy smartphone.
toggle quoted message
Show quoted text
-------- Original message -------- From: Kees T <windy10605@...> Date: 26/05/2018 17:56 (GMT+00:00) Subject: Re: [BITX20] ND6T AGC implementation for uBIT-X
Here it is 73 Kees K5BCQ
|
K9HZ
