|
I thought a 2N2219 was a 2N2222 in a bigger package that can handle a bit more heat, so basically the same device otherwise.
On??the following is attributed to Alison
Pre-driver?¨C?We need the gain again to be more stable and higher as well. Transistors tried that worked better included the TO18 2n2222A
Driver?¨CThis is where the 2n3904 really fails. Its bandwidth at high currents actually does down. The 2n2222A has the reverse, the gain and bandwidth increased with increasing current.
On HFsigs Farhan says
Transmitting?The power chain uses four common plastic 2N3904s in push-pull as drivers. The 2N3904s have enough gain at 30 MHz. The 2N2219s tried ?earlier were found to have low gain at higher frequencies.
So... which has more gain/performs better on ?~17, 15, 12,10 meters in the uBitx if you ignore cost??
Also so when did 2N2222s get costly? They were once called something like the ¡°cockroaches¡± of electronics.
tnx
jer aa1of
|
Jer
Nice logic flow. Well the higher quality 2n2222a with metal case are used a lot less by industry these days, ditto for 2n2219.
Remember these rigs are batch built, high volume for low cost, and surface mount, so different worlds.
Then there is factor of your interest vs time it costs you. I am not phased yet by the ubitx transmit power rolloff, although I have a rare one shipped with a dip at 7 MHz, but just an added cap cured that.
Enjoy your refinement exploration
Curt wb8yyy
|
Alison and Farhan are to both very credible resources but they seem to contradict each other. I had planned to follow Alison¡¯s advice and then saw what Farhan had written...
|
This is the 'Achilles Heel' of the open source movement.? Each user is free to implement their own modifications based on their education, experience and biases.? Who is wrong? Who is right? Are they all right in their own way?? Deciding which path to follow is WAY too existential for me!
|
The 2N2219 is physically bigger same Die inside so yes, you can use either.
I specified the smaller can 2n2222A as most would be easily bothered by
large transistor and small space.? Neither case heat is NOT and issue.
Heat for that sot is not a big issue, space is.? So if you use 2219s insert them
(observe pin out carefully) from the underside of the board.? That will allow
more room.
Allison
---------------------------------
No direct email, it goes to bit bucket due address harvesting in groups.IO
|
Hi ohwenzelph,
Short memory, you were here during the thick out it all back when.
Also anyone paying high prices for 2n2222A are nuts, seems the
supply of a lot of devices (leaded) are low (are we surprised?)
so everyone figure out to hose everyone else.??
FYI: the PN2222 and plastic friends are not the same device.
Never got the same performance from those.
Other known candidates include 2n3866, 2n5109 and likely others may be?
listed in the Wiki.
Allison
---------------------------------
No direct email, it goes to bit bucket due address harvesting in groups.IO
|
The original BITX20 design used 2N2222a devices.? Then we found that? many of these devices were inferior (if a floor sweeping tested as NPN, it? was labeled a 2N222a and marketed as such) and were being sold through? popular retail outlets.??
That situation resulted in a change from 2N2222a (plastic devices) to 2N3904, also plastic devices, that seemed to be more reliable and within specifications.
This was in the era when BITX transceivers were built using Ugly Construction? methods with parts from junk boxes and from local retailers.??
Arv _._
On Sat, May 30, 2020 at 12:29 PM ajparent1/kb1gmx < kb1gmx@...> wrote: Hi ohwenzelph,
Short memory, you were here during the thick out it all back when.
Also anyone paying high prices for 2n2222A are nuts, seems the
supply of a lot of devices (leaded) are low (are we surprised?)
so everyone figure out to hose everyone else.??
FYI: the PN2222 and plastic friends are not the same device.
Never got the same performance from those.
Other known candidates include 2n3866, 2n5109 and likely others may be?
listed in the Wiki.
Allison
---------------------------------
No direct email, it goes to bit bucket due address harvesting in groups.IO
|
¡° ?FYI: the PN2222 and plastic friends are not the same device.Never got the same performance from those.¡±
THANK YOU for that bit of information!! I would have been completely deceived. ?
toggle quoted message
Show quoted text
On May 30, 2020, at 14:38, Arv Evans <arvid.evans@...> wrote:
? The original BITX20 design used 2N2222a devices.? Then we found that? many of these devices were inferior (if a floor sweeping tested as NPN, it? was labeled a 2N222a and marketed as such) and were being sold through? popular retail outlets.??
That situation resulted in a change from 2N2222a (plastic devices) to 2N3904, also plastic devices, that seemed to be more reliable and within specifications.
This was in the era when BITX transceivers were built using Ugly Construction? methods with parts from junk boxes and from local retailers.??
Arv _._ On Sat, May 30, 2020 at 12:29 PM ajparent1/kb1gmx < kb1gmx@...> wrote: Hi ohwenzelph,
Short memory, you were here during the thick out it all back when.
Also anyone paying high prices for 2n2222A are nuts, seems the
supply of a lot of devices (leaded) are low (are we surprised?)
so everyone figure out to hose everyone else.??
FYI: the PN2222 and plastic friends are not the same device.
Never got the same performance from those.
Other known candidates include 2n3866, 2n5109 and likely others may be?
listed in the Wiki.
Allison
---------------------------------
No direct email, it goes to bit bucket due address harvesting in groups.IO
|
Hi Allison,
My concern is ¡°the 2n3904 really fails. Its bandwidth at high currents actually does down. The 2n2222A has the reverse, the gain and bandwidth increased with increasing current¡± vs ¡°The 2N3904s have enough gain at 30 MHz. The 2N2219s tried ?earlier were found to have low gain at higher frequencies.¡±
fwiw
thanks
|
I have several packages of 2n2222a from decades ago. I think I will keep those for my own use.
73,
Bill KU8H
toggle quoted message
Show quoted text
On 5/30/20 2:29 PM, ajparent1/kb1gmx wrote: Hi ohwenzelph,
Short memory, you were here during the thick out it all back when.
Also anyone paying high prices for 2n2222A are nuts, seems the
supply of a lot of devices (leaded) are low (are we surprised?)
so everyone figure out to hose everyone else.
FYI: the PN2222 and plastic friends are not the same device.
Never got the same performance from those.
Other known candidates include 2n3866, 2n5109 and likely others may be
listed in the Wiki.
Allison
---------------------------------
No direct email, it goes to bit bucket due address harvesting in groups.IO
--
bark less - wag more
|
I'd love to hear from anyone that can advise either where/how to acquire good quality 2N2222A, or 2N5109, of 2N3866 for a decent price.
Mouser has 2N2222A in stock, but the least expensive are now $4.49 in lots of 10.? 2N5109 are no longer available.? 2N3866 appear to be available but only for ordering in large lots.
I purchased some DCP68 that arrived today, but these are surface mount devices.? They're $0.325 each in lots of 10.? I haven't put them in a test circuit yet.
Andy
KG5RKP
toggle quoted message
Show quoted text
On Sat, May 30, 2020 at 01:29 PM, ajparent1/kb1gmx wrote:
Also anyone paying high prices for 2n2222A are nuts, seems the
supply of a lot of devices (leaded) are low (are we surprised?)
so everyone figure out to hose everyone else.??
<snip>
Other known candidates include 2n3866, 2n5109 and likely others may be?
listed in the Wiki.
Allison
---------------------------------
No direct email, it goes to bit bucket due address harvesting in groups.IO
|
Andy most are available but many places do not stiock so price is what it cost from
them to get a minimum order from a maker.? That way they can sell 10 and if that's
it sit on the other 9990 which has a cost as well.
Try Diz.?
I've bought a lot from him and not paid for this?
but its always quality parts.
2n2219s for 2/4$
2N3866? for 2/6$
IRF510 5/4$
And very much more including ferrites or all sizes and kinds.
IF you look harder like dans small parts and other like Allied electronics you are likely to find even more.
like:?? 73 cents,? 10/6.10$
Allison
---------------------------------
No direct email, it goes to bit bucket due address harvesting in groups.IO
|
Thanks for telling us all that.
toggle quoted message
Show quoted text
-----Original Message----- From: [email protected] [mailto: [email protected]] On Behalf Of Bill Cromwell Sent: Saturday, May 30, 2020 3:40 PM To: [email protected]Subject: Re: [BITX20] What¡¯s actually better? I have several packages of 2n2222a from decades ago. I think I will keep those for my own use. 73, Bill KU8H On 5/30/20 2:29 PM, ajparent1/kb1gmx wrote: Hi ohwenzelph,
Short memory, you were here during the thick out it all back when.
Also anyone paying high prices for 2n2222A are nuts, seems the supply
of a lot of devices (leaded) are low (are we surprised?) so everyone
figure out to hose everyone else.
FYI: the PN2222 and plastic friends are not the same device.
Never got the same performance from those.
Other known candidates include 2n3866, 2n5109 and likely others may be
listed in the Wiki.
Allison
---------------------------------
No direct email, it goes to bit bucket due address harvesting in
groups.IO
-- bark less - wag more -- This email has been checked for viruses by AVG. -- ¡_. _._
|
ozwelph
Really?? did you read the datasheet? also what current is the peak you expect?
The problem with 2n3904 is at 30Mhz getting more than 10DB gain is not
something reliable.? However the design of the stage counts on 16DB?
which is possible to about 10-12mhz.? that way even at 20M the power
is down from 80m
So if you want 16db of gain to hit 10M at full outout you need a
better part.
If the amp was deigned with one more stage and the gain held to 10db
it (2n3904) would be a good choice.? ?How do I know, I did it and tested.
Allison
---------------------------------
No direct email, it goes to bit bucket due address harvesting in groups.IO
|
You can always curve trace them if you are in doubt as to if they are real.? I keep my eyes open for ¡°JAN¡±¡ and good old original ¡°RCA¡± parts at the flea markets.? Extremely good quality¡ ? ?
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of AndyH
Sent: Saturday, May 30, 2020 5:11 PM
To: [email protected]
Subject: Re: [BITX20] What¡¯s actually better? ? I'd love to hear from anyone that can advise either where/how to acquire good quality 2N2222A, or 2N5109, of 2N3866 for a decent price.
Mouser has 2N2222A in stock, but the least expensive are now $4.49 in lots of 10.? 2N5109 are no longer available.? 2N3866 appear to be available but only for ordering in large lots.
I purchased some DCP68 that arrived today, but these are surface mount devices.? They're $0.325 each in lots of 10.? I haven't put them in a test circuit yet.
Andy
KG5RKP
On Sat, May 30, 2020 at 01:29 PM, ajparent1/kb1gmx wrote: Also anyone paying high prices for 2n2222A are nuts, seems the
supply of a lot of devices (leaded) are low (are we surprised?)
so everyone figure out to hose everyone else.??
<snip>
Other known candidates include 2n3866, 2n5109 and likely others may be?
listed in the Wiki.
Allison
---------------------------------
No direct email, it goes to bit bucket due address harvesting in groups.IO
-- ¡_. _._
|
I appreciate your time, Allison.? I also feel silly as I ordered NOS 2N2222A from Dan's Small Parts a month or three back. They're still $0.50 each plus a bit of shipping.? I've been trying to collect parts from Diz before they fall off.? I received a pair of 2N5109 from him today in his RF amp kits.? There are '5109s on ebay, but pricy.? I've been trying to duplicate stages from EI9GQ/Eamon's multi-band transceiver and this relative RF noob is struggling to get some of the rapidly-becoming-obsolete bits.? I envy the experienced folks with deep junque boxes!
Best, Andy
toggle quoted message
Show quoted text
On Sat, May 30, 2020 at 05:39 PM, ajparent1/kb1gmx wrote:
Andy most are available but many places do not stiock so price is what it cost from
them to get a minimum order from a maker.? That way they can sell 10 and if that's
it sit on the other 9990 which has a cost as well.
Try Diz.?
I've bought a lot from him and not paid for this?
but its always quality parts.
2n2219s for 2/4$
2N3866? for 2/6$
IRF510 5/4$
And very much more including ferrites or all sizes and kinds.
IF you look harder like dans small parts and other like Allied electronics you are likely to find even more.
like:?? 73 cents,? 10/6.10$
Allison
---------------------------------
No direct email, it goes to bit bucket due address harvesting in groups.IO
|
Hi ohwenzelph,
Allison's metal 2n2222a transistors should be comparable to 2n2219a transistors, but like always the source of the transistors needs to be researched.? If Allison got good results with her 2n2222a and Farhan got bad results with his 2n2219, then it could be that the latter transistors were suspect.
Also note that she was using the improved "A" version of the transistor and it seems that Farhan was not.? The "A" version has higher hFE and hfe? and lower Vsat than the non-A version.
73.
|
Mark,
Your speculating on a created phantom.? The 2n2219 is a 2222A in a TO5 can
vs to18?same Die.
Datasheet enclosed for both from the same vendor!
Allison
---------------------------------
No direct email, it goes to bit bucket due address harvesting in groups.IO
|
Well,
I was looking at a datasheet that had both the 2219 and 2219A listed and there was a difference between the two:
I usually try to research things a bit before I post them.? Did I get it wrong?
Mark
|
A 2N2219A is just a 2N2222A with higher power dissipation (between 50% and 100% more) due to the larger metal can.? That¡¯s all. ? ?
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of Mark - N7EKU
Sent: Sunday, May 31, 2020 3:29 PM
To: [email protected]
Subject: Re: [BITX20] What¡¯s actually better? ? Well,
I was looking at a datasheet that had both the 2219 and 2219A listed and there was a difference between the two:
I usually try to research things a bit before I post them.? Did I get it wrong?
Mark -- ¡_. _._
|
MadRadioModder