Re: Buyer beware! RD16HHF1
Re-reading what you wrote, I see there's nothing said about IRF510 vs RD16HHF1.
Guess I was reading between the lines, as $0.50 has been given here as the price of the IRF510.
My apologies.
> I think it's false economy of both my time and money to blow up a few dozen $0.50 parts,
> chasing issues created by the selection of an inferior part from an unreliable source,
> when one appropriately selected and sourced $4.75 part will accomplish MY goal?
Jerry
toggle quoted message
Show quoted text
On Sun, May 13, 2018 at 10:16 am, Russ Hines wrote:
This reply is another reason I rarely post.? But thank you for your implication.? I was simply offering my opinion.? I now regret doing so.
|
Kees,
Please put me down for one each of the Click Fix and AGC boards.
I'd like a SWR board when it is available.
thank you,
Bill K6SIK
|
Re: Buyer beware! RD16HHF1
<sigh>
This reply is another reason I rarely post.? But thank you for your
implication.? I was simply offering my opinion.? I now regret doing
so.
73,
Russ Hines
WB8ZCC
--
Reply to: russ@...
On 5/13/2018 12:17, Jerry Gaffke via
Groups.Io wrote:
toggle quoted message
Show quoted text
Allison has quite a
few posts here.
None have discouraged experimentation with the IRF510's.
Quite the contrary.
She did however suggest you get your RF parts from reliable
vendors,
be they IRF510's or RD16HHF1's.
Jerry
On Sun, May 13, 2018 at 08:54 am, Russ Hines wrote:
Gents and ladies, I don't post much as I'm a busy
broadcast engineer.? But I try to read often.
Allison's post contains wisdom.
Education tends to be expensive.? If your goal is IRF R&D,
then knock yourselves out.? You will go through a lot of parts,
and likely as not, spend a lot more time and money in acquiring
the knowledge and experience.? In the end, you'll know what a
part can or cannot do.? If that's YOUR goal, great.
For myself, my time is worth something to me.? I think it's
false economy of both my time and money to blow up a few dozen
$0.50 parts, chasing issues created by the selection of an
inferior part from an unreliable source, when one appropriately
selected and sourced $4.75 part will accomplish MY goal - to use
a piece of equipment that I built.? The former is not worth the
hassle.
If you need a cliche, here's two:? I'd like to "not reinvent the
wheel," but would much rather "stand on the shoulders of
giants."
Two cents duly submitted.
73,
Russ Hines
WB8ZCC
--
Reply to: russ@.
|
Hi Jerry,
Yes you are right, some sound okay and others don't. At the cheap price of Electret elements, I order some from several different sources and just solder in one at a time and listen to myself on another receiver until I find the one that sounds best. Works for me.
Joel
N6ALT
|
Re: uBITX narrow IF filter mod for CW, anyone tried this?
Increasing the caps as Farhan pointed out elsewhere would fine but then you should adjust the BFO
to put the signals in the passband.? That mod however makes SSB really poor both RX and TX.
While I've not done this on a bitx because to me its primary SSB radio.? I have made CW filters?
for tests using that technique.? A good example of this however is Kitsandparts 1W, the crystal
filter is?optimized for CW and works well.
If one were really wishing to experiment replacing the caps with a smaller value and then putting
Varicap at each point results in an adjustable bandwidth filter [look up Jones Filter].? I've played
with this and it does work well.? ?It was applied in the Elecraft K2 receiver as a working example.
Allison
|
Though many report good performance from the mike element that comes with the kit.
At around $0.10 each, it's possible the quality might vary a bit between units
and between manufacturers.
Jerry
toggle quoted message
Show quoted text
On Sun, May 13, 2018 at 09:54 am, Joel Caulkins wrote:
"address the microphone audio"
Not sure what there is to address about the mic audio. I have built 5 BitXs including the uBitx and I get good audio reports on all of them, of course I'm using the same? two mics that I built my self and I think that is why my audio is good. I found that the electret capsules supplied with the bitxs sounded tinny and pinched, so I bought 10 from China for $1.00 US delivered to my door and found they sounded great, so try a different mic, you might be amazed rather than redesigning the circuit to fit those mic elements.
Joel
N6ALT
|
"address the microphone audio"
Not sure what there is to address about the mic audio. I have built 5 BitXs including the uBitx and I get good audio reports on all of them, of course I'm using the same? two mics that I built my self and I think that is why my audio is good. I found that the electret capsules supplied with the bitxs sounded tinny and pinched, so I bought 10 from China for $1.00 US delivered to my door and found they sounded great, so try a different mic, you might be amazed rather than redesigning the circuit to fit those mic elements.
Joel
N6ALT
|
Re: Buyer beware! RD16HHF1
?I don't know if y'all have already done that....but writing up a little "white paper"" and putting it on the web site about little bite-size improvement steps like going to the RD16HHF1 for example, would make very helpful little bite-sized projects.? ?
Again, you may have already done all that.
I'm submitting gerber files right now to get my cheap homebrew soundcard-interface done as prototype batch?--- it is very similar to the EasyDigi but includes gain potentiometer trimmers and a RELAY for the push to talk, LED ptt indicator.? ??If it works....it
will be freely available.? ?The previous (expensive-PCB-company-version) went through about 40 [expensive]??copies locally and elsewhere and many are 24/7/365 in service).? ? You guys have taught me a lot!!!!
gordon
toggle quoted message
Show quoted text
Also, keep in mind that if you plan to move from the IRF510 to the RD16HHF1,?
the uBitx final should have some adjustments to the transformer ratios and such.
The RD16HHF1 is not quite a drop in replacement.
Jerry
On Sun, May 13, 2018 at 09:17 am, Jerry Gaffke wrote:
Allison has quite a few posts here.
None have discouraged experimentation with the IRF510's.
Quite the contrary.
She did however suggest you get your RF parts from reliable vendors,
be they IRF510's or RD16HHF1's.
Jerry
. . .
?
On Sun, May 13, 2018 at 08:54 am, Russ Hines wrote:
Gents and ladies, I don't post much as I'm a busy broadcast engineer.? But I try to read often.
Allison's post contains wisdom.
Education tends to be expensive.? If your goal is IRF R&D, then knock yourselves out.? You will go through a lot of parts, and likely as not, spend a lot more time and money in acquiring the knowledge and experience.? In the end, you'll know what a part can
or cannot do.? If that's YOUR goal, great.
For myself, my time is worth something to me.? I think it's false economy of both my time and money to blow up a few dozen $0.50 parts, chasing issues created by the selection of an inferior part from an unreliable source, when one appropriately selected and
sourced $4.75 part will accomplish MY goal - to use a piece of equipment that I built.? The former is not worth the hassle.
If you need a cliche, here's two:? I'd like to "not reinvent the wheel," but would much rather "stand on the shoulders of giants."
Two cents duly submitted.
73,
Russ Hines
WB8ZCC
--
Reply to: russ@.
|
Re: Are the uBITX receivers ripe for improvement? -- And some other miscellaneous thoughts.
Receiver performance has many dimensions.
?Sensitivity
?Bandwidth
?Overload performance and dynamic range.
?Stability, Especially important in the days of VFOs.
?Spurious signals, birdies and unexpected signals.
?
?This one is unique to a new generation of simple radios with microcomputers to
?enhance and provide a user interface.
?From my perspecitive and work I've done the ITX 40 had too much gain and required
?an attenuator most nights.? An easy fix.? ?The ubitx I have as a RX only test bed from
?about 3-4 years ago ding the Minima development is a good receiver in the 1-10 mhz
?range but I prefer a bit of RF gain added for 10 through 30mhz.? ? As you go up there
?is more weak signal propagation and reduced manmade and approaches galactic noise
?floor.? That said at 40M a 1uV senstivity is plenty, at 28mhz .2uV is more useful.
?For selectivity, I prefer a tight filter.? 2.1 to 2.4khz is fine as the would of SSB is
?about that wide on transmit save for the ESSB people where a 3khz filter would
?be better.? I however prefer steeper skirts and that requires more crystals to do?
?with 5 crystals being the bare minimum and 7 seems to be approaching very good.
?Why is this important, strong signals down the skirts[edges] are audible of not suppressed
?enough and if the same filter is for TX it assures unwanted sideband is suppressed.
Overload, this is a big area for bitx40 users and same for bitx20 as there is a lot of RF gain
and those bands are known for big signals.? Attenuation or circuit changes help greatly.
The uBITX runs with out RF gain and was optimized for a decently high overload point.
So fewer people complain of overload but for both flavors AGC is a common wish list item.
Stability has been mostly solved by going with NCOs Si5351 and Si570.? The price is adding
an Arduino microprocessor, LCD display and a some form of encoder to tune.? ? The other prices
is there will be signals generates by the microprocessor and its communicating with external
devices like the display.? It does add and open a whole new arena of user interface that didn't
exist in earlier analog designs.? An example of this is KB1OIQ's version of uBitx that is blind
user friendly (speech synth output and keypad controls) as its really well thought out.
An aside, adding a Rpi or similar [STMFxx series] to do signal processing is on face a good idea?
but the cost is considerable software development, more sophisticated user interface and power.
The last item is important to a compact portable radio, many wish to use batteries and a Rpi eats?
about? 3-4watts.? Adding touch screen adds another 3-5 watts to that.? At some point its not a simple
radio nor inexpensive and has become battery unfriendly.? Some problems noted are analog in
nature and easily solved without resorting to?a computer.?
FYI look at working being done for the various SDR radios.? If you are going digital its smarter to
start with a new architecture and build in the computer rather than hang it on like a laptop on the side.
With all that said, yes a decent receiver.? Can it be improved?? Yes.? Define, improved first
as many have a different idea of what that may be and in some cases its not even a receiver issue.
Allison
|
Re: Buyer beware! RD16HHF1
Allison,??
Please don't get offended as this is just my 2 cents worth.
Of your list, only RFParts has the?RD16HHF1. Ordering 4 for $19.00 and a dollars worth of something else to meet the $20.00 minimum plus shipping?to me?is $9.50 is $29.50. Forgetting the dollars worth of something it works out to $7.12. No thanks, I'll buy elsewhere.
|
Re: Buyer beware! RD16HHF1
Also, keep in mind that if you plan to move from the IRF510 to the RD16HHF1,?
the uBitx final should have some adjustments to the transformer ratios and such.
The RD16HHF1 is not quite a drop in replacement.
Jerry
toggle quoted message
Show quoted text
On Sun, May 13, 2018 at 09:17 am, Jerry Gaffke wrote:
Allison has quite a few posts here.
None have discouraged experimentation with the IRF510's.
Quite the contrary.
She did however suggest you get your RF parts from reliable vendors,
be they IRF510's or RD16HHF1's.
Jerry
. . .
?
On Sun, May 13, 2018 at 08:54 am, Russ Hines wrote:
Gents and ladies, I don't post much as I'm a busy broadcast engineer.? But I try to read often.
Allison's post contains wisdom.
Education tends to be expensive.? If your goal is IRF R&D, then knock yourselves out.? You will go through a lot of parts, and likely as not, spend a lot more time and money in acquiring the knowledge and experience.? In the end, you'll know what a part can or cannot do.? If that's YOUR goal, great.
For myself, my time is worth something to me.? I think it's false economy of both my time and money to blow up a few dozen $0.50 parts, chasing issues created by the selection of an inferior part from an unreliable source, when one appropriately selected and sourced $4.75 part will accomplish MY goal - to use a piece of equipment that I built.? The former is not worth the hassle.
If you need a cliche, here's two:? I'd like to "not reinvent the wheel," but would much rather "stand on the shoulders of giants."
Two cents duly submitted.
73,
Russ Hines
WB8ZCC
--
Reply to: russ@.
|
Re: uBITX drive level..
#ubitx
Going to 150ma should be fine, so long as those IRF510 tabs are not getting so hot that it's uncomfortable to keep your finger on it. But those bias pots are very touchy once you get into the active region of the FET's, it's quite easy to turn it a bit too far and have 1500 ma instead of 150 ma. Here's a pertinent post: ? ? /g/BITX20/message/47871Jerry, KE7ER
On Sun, May 13, 2018 at 08:25 am, <docame12@...> wrote:
Hi Jerry,
What do you mean by "Be very careful about setting those pots to "a lot more" than 100ma,?
that's a good way to make the IRF510's pop from the heat." What's? a lot more? I found I needed to adjust my bias to 150mA each just to get the PO to be on par with most others. By your formula above I would get? 12v*0.150A=1.8 watt. Am I correct??
Do you - or anyone here - have suggested maximum bias mA's? (BTW, I have a rather large computer cabinet fan that I salvaged and blow directly on the PAs.}
Thanks!
Dave, WS1ETI
|
Re: ND6T AGC implementation for uBIT-X
Kees,
Please put me down for two each of the Click Fix and AGC boards.
Also interested in the SWR boards when they are available.
73, Kevin KB3OMM
|
|
|
Re: Buyer beware! RD16HHF1
Allison has quite a few posts here.
None have discouraged experimentation with the IRF510's.
Quite the contrary.
She did however suggest you get your RF parts from reliable vendors,
be they IRF510's or RD16HHF1's.
Jerry
toggle quoted message
Show quoted text
On Sun, May 13, 2018 at 08:54 am, Russ Hines wrote:
Gents and ladies, I don't post much as I'm a busy broadcast engineer.? But I try to read often.
Allison's post contains wisdom.
Education tends to be expensive.? If your goal is IRF R&D, then knock yourselves out.? You will go through a lot of parts, and likely as not, spend a lot more time and money in acquiring the knowledge and experience.? In the end, you'll know what a part can or cannot do.? If that's YOUR goal, great.
For myself, my time is worth something to me.? I think it's false economy of both my time and money to blow up a few dozen $0.50 parts, chasing issues created by the selection of an inferior part from an unreliable source, when one appropriately selected and sourced $4.75 part will accomplish MY goal - to use a piece of equipment that I built.? The former is not worth the hassle.
If you need a cliche, here's two:? I'd like to "not reinvent the wheel," but would much rather "stand on the shoulders of giants."
Two cents duly submitted.
73,
Russ Hines
WB8ZCC
--
Reply to: russ@.
|
Re: Buyer beware! RD16HHF1
THe only place I buy RF transistors from is RFparts, Digikey, Mouser, Kitsandparts, and Jameco.
When it comes to oddball or scarce parts its RFParts as they do stand behind theirs,??
RD16HHF there is 4.75 last I looked.? That is a fair price for them.?
The last bunch of IRF510s were Vishey from Digikey, paid under 10$ for 10 of them.
There is no bargain if you buy fakes and then have to buy the real ones.? Then there
is lost time and potential for damage from fakes.
Allison
|
Re: Are the uBITX receivers ripe for improvement? -- And some other miscellaneous thoughts.
There's a thread on the B40's sensitivity here. Signals were heard down to -130dbm and the results were verified. /g/BITX20/topic/5447469#30094Vince.
On 05/13/2018 09:25 AM, richcarter03052 wrote: I hooked up a calibrated signal source and verified that I can receive a
1uv signal on all bands. This is consistent with performance of most
modern rigs. I find the rig a bit difficult to tune however, possibly
due to an SSB filter that is too wide.
Rich - KE1EV
--
Michigan VHF Corp.
|
Re: Buyer beware! RD16HHF1
Gents and ladies, I don't post much as I'm a busy broadcast engineer.? But I try to read often.
Allison's post contains wisdom.
Education tends to be expensive.? If your goal is IRF R&D, then knock yourselves out.? You will go through a lot of parts, and likely as not, spend a lot more time and money in acquiring the knowledge and experience.? In the end, you'll know what a part can or cannot do.? If that's YOUR goal, great.
For myself, my time is worth something to me.? I think it's false economy of both my time and money to blow up a few dozen $0.50 parts, chasing issues created by the selection of an inferior part from an unreliable source, when one appropriately selected and sourced $4.75 part will accomplish MY goal - to use a piece of equipment that I built.? The former is not worth the hassle.
If you need a cliche, here's two:? I'd like to "not reinvent the wheel," but would much rather "stand on the shoulders of giants."
Two cents duly submitted.
73,
Russ Hines
WB8ZCC
--
Reply to: russ@...
toggle quoted message
Show quoted text
On 5/12/2018 14:07, ajparent1/KB1GMX wrote: I do not buy parts on ebay, I have extreme distrust.? there are plenty of vendors that sell
parts that I don't require paypal and are considered quality vendors.
|
Yes this was a popular way of varying the bandwidth of filters in its time.? Varying the capacitance of the diodes via voltage to vary the roll-off frequency/sharpness of the filters. Quite simple to do. ? ? Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ ? Owner - Operator Big Signal Ranch ¨C K9ZC Staunton, Illinois ? Owner ¨C Operator Villa Grand Piton ¨C J68HZ Soufriere, St. Lucia W.I. Rent it: Like us on Facebook! ? Moderator ¨C North American QRO Group at Groups.IO. ? email:? bill@... ? ?
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of jim via Groups.Io
Sent: Sunday, May 13, 2018 10:30 AM
To: [email protected]
Subject: Re: [BITX20] uBITXII? On Sunday, May 13, 2018, 6:22:30 AM PDT, richcarter03052 <re.carter@...> wrote: I built a fully featured Elecraft K2 a few years back.? It has a variable bandwidth crystal ladder filter.? I wonder if the uBitx filter can be adapted to vary it's bandwidth in a similar fashion, perhaps with an external pot rather than under processor control. I,too have a k2 ...the diode used is a type 1sv149 500pf@1 volt to 20pf@ 7 volts ...been looking at that contemplating a test mod to see what happens for a while ...
|
Re: Buyer beware! RD16HHF1
Hi this an interesting read.
?
Cheers
Kevin
VK2KTG
|
Joel Caulkins/N6ALT
K9HZ