can any one provide me the inductance value of the coils used in bitx20 v3
BITX20hi,
I am trying to construct my bitx20 v3,and I cannot find the insulated copper wire of the same gauge in my local market,
can any one provide me the inductance value of the coils used in bitx20 v3,
T1,T1A,T2,T3, the circuit says 13 turns of 32 swg gauge wire on tv balun core..
thanks
shubham tiwari
vu3sxn
|
Re: Bitx20a stabilize mod by PA3BWI
Thank you ARV for your info! RON
toggle quoted message
Show quoted text
--- In BITX20@..., arv <arvid.evans@...> wrote:
Ron
Power with and without the PA3BWI mods should not be different by more
than 1 or 2 percent. If more than that I would suspect that your IRF510's
may have been oscillating on signal peaks and that the PA3BWI mods have
eliminated that spurious oscillation.
Not sure how much power you are getting, or how much you are trying to
get. The BITXxxA transceiver output impedance matching is designed for
10 to 12 watts output. It is usually possible to get 16 watts out with
a 13.6
volt power supply but that causes RF peak compression due to impedance
mismatch if the final is driven to that level.
Yes, you can add the 0.1 mfd cap across R7 in BITX20A, BITX17A, and
other band versions as well. In prototype testing we did not need it in the
BITX20A version, and definitely did not need it in the BITX40A build.
Adding
this capacitor to the BITX17A was thought necessary because some IRF510
devices needed a little more drive at 18 MHz.
Arv K7HKL
_._
On 06/29/2013 12:00 PM, ronbaechle wrote:
After adding 1K resistor between drains Q18 and Q19 and 220 ohm across
pri t3 noticed lower pwr. Will adding .1 mf increase drive like stated
for Bitx17a? Before experimenting will this same value work on
Bitx20a? Thanks Ron
[Non-text portions of this message have been removed]
|
Re: Bitx20a stabilize mod by PA3BWI
Ron
Power with and without the PA3BWI mods should not be different by more
than 1 or 2 percent. If more than that I would suspect that your IRF510's
may have been oscillating on signal peaks and that the PA3BWI mods have
eliminated that spurious oscillation.
Not sure how much power you are getting, or how much you are trying to
get. The BITXxxA transceiver output impedance matching is designed for
10 to 12 watts output. It is usually possible to get 16 watts out with
a 13.6
volt power supply but that causes RF peak compression due to impedance
mismatch if the final is driven to that level.
Yes, you can add the 0.1 mfd cap across R7 in BITX20A, BITX17A, and
other band versions as well. In prototype testing we did not need it in the
BITX20A version, and definitely did not need it in the BITX40A build.
Adding
this capacitor to the BITX17A was thought necessary because some IRF510
devices needed a little more drive at 18 MHz.
Arv K7HKL
_._
toggle quoted message
Show quoted text
On 06/29/2013 12:00 PM, ronbaechle wrote:
After adding 1K resistor between drains Q18 and Q19 and 220 ohm across
pri t3 noticed lower pwr. Will adding .1 mf increase drive like stated
for Bitx17a? Before experimenting will this same value work on
Bitx20a? Thanks Ron
|
Re: binocular cores - to twist or not to twist!
I have a few rolls of what looks like 30ga ribbon cable. It was used in hard drives. I've posted pictures of it in the past but can't find them. It's my wire of choice for torroids. It was expensive though on the retail market.
Leonard
toggle quoted message
Show quoted text
--- In BITX20@..., Jim <n6otq@...> wrote:
Add to all this -- twist your windings and it makes it a lot easier to wind.
73
Jim N6OTQ?
________________________________
From: Raj <vu2zap@...>
To: BITX20@...
Sent: Saturday, June 29, 2013 7:42 AM
Subject: RE: [BITX20] binocular cores - to twist or not to twist!
Ahem! elaborating for Sandeep..
Twisted pairs have lesser capacitance with the next turn or layer than untwisted pairs of wires AFAIK!
Twisted pairs in balanced configuration also reduces the stray signal pickup from nearby circuits/radiators.
73
--
Raj, vu2zap
|
Bitx20a stabilize mod by PA3BWI
After adding 1K resistor between drains Q18 and Q19 and 220 ohm across pri t3 noticed lower pwr. Will adding .1 mf increase drive like stated for Bitx17a? Before experimenting will this same value work on Bitx20a? Thanks Ron
|
Re: binocular cores - to twist or not to twist!
Add to all this -- twist your windings and it makes it a lot easier to wind. 73 Jim N6OTQ? ________________________________
From: Raj <vu2zap@...>
To: BITX20@...
Sent: Saturday, June 29, 2013 7:42 AM
Subject: RE: [BITX20] binocular cores - to twist or not to twist!
Ahem! elaborating for Sandeep..
Twisted pairs have lesser capacitance with the next turn or layer than untwisted pairs of wires AFAIK!
Twisted pairs in balanced configuration also reduces the stray signal pickup from nearby circuits/radiators.
73
--
Raj, vu2zap
[Non-text portions of this message have been removed]
|
Re: binocular cores - to twist or not to twist!
Ahem! elaborating for Sandeep.. Twisted pairs have lesser capacitance with the next turn or layer than untwisted pairs of wires AFAIK! Twisted pairs in balanced configuration also reduces the stray signal pickup from nearby circuits/radiators. 73 -- Raj, vu2zap At 29-06-2013, you wrote: What has this to do with the question asked?
Lee ¨C N9LO
Sent from my Windows PC, a real computer.
From: <mailto:BITX20%40yahoogroups.com>BITX20@... [mailto:BITX20@...] On Behalf Of Sandeep Lohia
Sent: Saturday, June 29, 2013 6:40 AM
To: <mailto:BITX20%40yahoogroups.com>BITX20@...
Subject: Re: [BITX20] binocular cores - to twist or not to twist!
TWIST FOR CAPACITANCE... [Non-text portions of this message have been removed]
|
Re: binocular cores - to twist or not to twist!
TWIST FOR CAPACITANCE... On 29/06/2013, brum_57 <k.p.williams@...> wrote: Hi folks, my first post to the group, I'm looking forward to constructing
this great little transceiver.
Although I'm an experienced constructor sometimes I do get my head in a mess
when it comes to toroids and balun cores (I'm sure I'm not alone)
So my question is - with binocular cores is it necessary to twist together
the windings as you would with a toroid? I didn't in my last project which
works well but I have seen pictures on the net where windings appear to have
been twisted. Does it really make any difference with binocular cores?
Best 73 Kevin GW4WOV
-- -- Due to ongoing technological advancement, many of electronic products become obsolete within a very short period of time, creating a large surplus of unwanted electronic products. E-waste being produced could increase by as much as 500 percent over the next ten years as the use of electronic equipment grows. Lack of consensus and irresponsible way to deal with reuse, recycling causes release of toxins into the environment. whereas most of the materials used in electronic equipment can be reclaimed, recycled, repaired and reused to produce new products. Contaminants from e-waste enter the soil, air, and water. thus entering food chain can Contaminate DNA permanently those of new born. An average electronic-gazet can contain up to 1,000 toxins, including lead, copper, cadmium, mercury, sulphur, Beryllium oxide, and other heavy metals, that are known to damage the nervous system, kidneys, causes cancer, brain mental impairment, thyroid problems, liver problems, disrupt the endocrine system, and birth defects. Although there is legislation that encourages recycling, repairing, neutralizing of e-waste, it's our duty to enforce anti- dumping laws, rather than dumping is necessary. Please encourage recycling or reuse of E-waste. ?7?3? ?d?e? ?V?U?3?S?X?T?
|
Did you test your crystal in a stand alone oscillator ?
The only way to see what the original Freq is .
The circuit ( bfo ) is maybe oscillating by himself stronger then the signal from your crystal . In that case the crystal no longer act as but only as a self with a C.
Marc
|
Re: binocular cores - to twist or not to twist!
--- In BITX20@..., "brum_57" <k.p.williams@...> wrote:
Hi folks, my first post to the group, I'm looking forward to constructing this great little transceiver.
Although I'm an experienced constructor sometimes I do get my head in a mess when it comes to toroids and balun cores (I'm sure I'm not alone)
So my question is - with binocular cores is it necessary to twist together the windings as you would with a toroid? I didn't in my last project which works well but I have seen pictures on the net where windings appear to have been twisted. Does it really make any difference with binocular cores?
Best 73 Kevin GW4WOV
A good question. Why twist the wires together in the first place? For the same reason as one makes coaxial cable or ladder line: to provide a uniform impedance match from one end of the wires to the other. It doesn't really matter a whole lot at HF and below with small inductances...but it can't hurt. It's a quite different story for transmission lines. And for VHF. There even small impedance mismatches make big differences. So, should you twist wires on dumbbell cores? You don't have to, but it may help and it doesn't hurt. If your are making a transformer to match impedances, it definitely helps to have known uniform distances between wires. Twisting them together uniformly helps to achieve that. john AD5YE
|
binocular cores - to twist or not to twist!
Hi folks, my first post to the group, I'm looking forward to constructing this great little transceiver.
Although I'm an experienced constructor sometimes I do get my head in a mess when it comes to toroids and balun cores (I'm sure I'm not alone)
So my question is - with binocular cores is it necessary to twist together the windings as you would with a toroid? I didn't in my last project which works well but I have seen pictures on the net where windings appear to have been twisted. Does it really make any difference with binocular cores?
Best 73 Kevin GW4WOV
|
I meant to say the 15pf in parallel
with the variable cap. I put in a 22pf cap. I tested the 15pf and discovered it is a 150pf. It is one of those little plastic NPO's with the markings illegible. It was in a plastic bag marked 15pf. Leonard your suspicions were right.No wonder I couldn't get any adjustment. I wonder now if I go back from 22pf to 15pf if I will get more adjustment. 2KC's is not very much. Jerry K5LRU
toggle quoted message
Show quoted text
--- In BITX20@..., "jerryk5lru" <jerry@...> wrote:
I think I found the problem, or at least part of it. I changed the 15pf capacitor in series with the variable cap and replaced it with a 22pf. I now have almost 2KC of tuning. I can actually hear changes when I adjust the variable cap. But it still doesn't seem like it is enough. I'll try and tune the carrior modulator and see how that goes. Jerry K5LRU
--- In BITX20@..., "Paul Daulton" <k5wms@> wrote:
Jerry I wonder if your xtal\s came with thie kit or you sourced them
some where else? Try swaping an xtal from filter with the bfo xtal.
Could the xtals be series resonant type? rather than parralell types?
Paul k5wms
Quoting jerryk5lru :
Arvid
I wound a 37-6 with fifty turns as per the calculator, worse. I shorted
the crystal and found I had moved lower to 6190. from the 8200. But
still had the 135 KC tunable range with the crystal shorted. I played
with the coil until I got it to the 9995. range with the crystal
shorted and still had 135 KC tuning range, when I removed the short it
went back to just a 5HZ tuning range.
--- In BITX20@..., arv wrote:
Jerry K5LRU
That indicates that your BFO oscillator should be tunable. Next step would
be to check capacitor and inductor values to make it tune across the crystal
frequency. You can change the inductor to a toroid core (T37-6 should work)
and adjust the turns until you get it to the right frequency. Toroid
calculator
located at can help with that task.
Arv K7HKL
_._
On 06/27/2013 10:59 PM, jerryk5lru wrote:
The crystal brand is KDS. I took your advice Arv and shorted the >
crystal out and the frequency tuned from 8104. MHz to 8239. Mhz 105
KC > range. But way lower than the 9995. Mhz area. Jerry K5LRU
--- In BITX20@... , arv > > wrote: > > > > > > Jerry
K5LRU > > > > > > The LC network in series with the crystal
(including series-C of the two > > > feedback divider caps) needs to
tune to the crystal frequency. Tuning > > > this resonant network a
bit above to a bit below the crystal frequency > > > is what pulls it
up or down. > > > > > > I would check the resonance components
associated with the crystal. > > > You might be able to get an idea
of what is going on by temporarily > > > soldering a very short wire
across the crystal to take it > > out-of-circuit. > > > Then check
the oscillator frequency. It should be close to the crystal > > >
frequency with the crystal shorted. Tuning range with the crystal > >
shorted will be more than with the crystal in-circuit, but this will > > tell > > > you if your tunable network really is tunable. >
Arv K7HKL > > > _._ > > > > > > On 06/27/2013 12:02 PM,
Paul Daulton wrote: > > > > > > > > > > > > > > > > What type and
brand of xtals are you using? > > > > > > > > Paul k5wms > > > > > >
Quoting jerryk5lru : > > > > > > > > This is a Bitx20 Version 3.
I'm almost done with it. The receiver > > > > receives good, the VFO
bandwidth is between 14,000. and 14,450. The > > > > exciter produces
a signal of 500mv and the PA kicks that up to > > around 4 > > > >
volts. When trying to tune the BFO and the carrier balance is where I
have the problem. My frequency is 9995.31 mhz at the emitter
of Q9. > > > > Here is where the problem starts. Leonards
instructions say I should > > > > have 15kc adjustment. But all I
have is about 3 hertz, not kilohertz > > > > with the 22pf trimmer.
So when I try to adjust the carrier balance, in > > > > transmit, 7
db down the filter skirt, I have no adjustment. The > > carrier > > >
balance is .321mv on the low side and .634mv on the high side. It >
nulls > > > > out in the middle of the pot. This is why I think I'm not getting > > > > enough drive. Any thoughts? Thanks, Jerry K5LRU >
Paul Daulton K5WMS > > > > beacon WMS 185.302 khz
qrss30/slow 24/7 > > > > Jacksonville,Ar 72076 > > > > em34wu > > > >
[Non-text portions of this message have been removed] > > > >
[Non-text portions of this message
have been removed] > > > > > > > > > > > [Non-text portions of this
message have been removed] > Paul Daulton K5WMS beacon WMS 185.302 khz
qrss30/slow 24/7 Jacksonville,Ar 72076 em34wu
|
I think I found the problem, or at least part of it. I changed the 15pf capacitor in series with the variable cap and replaced it with a 22pf. I now have almost 2KC of tuning. I can actually hear changes when I adjust the variable cap. But it still doesn't seem like it is enough. I'll try and tune the carrior modulator and see how that goes. Jerry K5LRU
toggle quoted message
Show quoted text
--- In BITX20@..., "Paul Daulton" <k5wms@...> wrote:
Jerry I wonder if your xtal\s came with thie kit or you sourced them
some where else? Try swaping an xtal from filter with the bfo xtal.
Could the xtals be series resonant type? rather than parralell types?
Paul k5wms
Quoting jerryk5lru :
Arvid
I wound a 37-6 with fifty turns as per the calculator, worse. I shorted
the crystal and found I had moved lower to 6190. from the 8200. But
still had the 135 KC tunable range with the crystal shorted. I played
with the coil until I got it to the 9995. range with the crystal
shorted and still had 135 KC tuning range, when I removed the short it
went back to just a 5HZ tuning range.
--- In BITX20@..., arv wrote:
Jerry K5LRU
That indicates that your BFO oscillator should be tunable. Next step would
be to check capacitor and inductor values to make it tune across the crystal
frequency. You can change the inductor to a toroid core (T37-6 should work)
and adjust the turns until you get it to the right frequency. Toroid
calculator
located at can help with that task.
Arv K7HKL
_._
On 06/27/2013 10:59 PM, jerryk5lru wrote:
The crystal brand is KDS. I took your advice Arv and shorted the >
crystal out and the frequency tuned from 8104. MHz to 8239. Mhz 105
KC > range. But way lower than the 9995. Mhz area. Jerry K5LRU
--- In BITX20@... , arv > > wrote: > > > > > > Jerry
K5LRU > > > > > > The LC network in series with the crystal
(including series-C of the two > > > feedback divider caps) needs to
tune to the crystal frequency. Tuning > > > this resonant network a
bit above to a bit below the crystal frequency > > > is what pulls it
up or down. > > > > > > I would check the resonance components
associated with the crystal. > > > You might be able to get an idea
of what is going on by temporarily > > > soldering a very short wire
across the crystal to take it > > out-of-circuit. > > > Then check
the oscillator frequency. It should be close to the crystal > > >
frequency with the crystal shorted. Tuning range with the crystal > >
shorted will be more than with the crystal in-circuit, but this will > > tell > > > you if your tunable network really is tunable. >
Arv K7HKL > > > _._ > > > > > > On 06/27/2013 12:02 PM,
Paul Daulton wrote: > > > > > > > > > > > > > > > > What type and
brand of xtals are you using? > > > > > > > > Paul k5wms > > > > > >
Quoting jerryk5lru : > > > > > > > > This is a Bitx20 Version 3.
I'm almost done with it. The receiver > > > > receives good, the VFO
bandwidth is between 14,000. and 14,450. The > > > > exciter produces
a signal of 500mv and the PA kicks that up to > > around 4 > > > >
volts. When trying to tune the BFO and the carrier balance is where I
have the problem. My frequency is 9995.31 mhz at the emitter
of Q9. > > > > Here is where the problem starts. Leonards
instructions say I should > > > > have 15kc adjustment. But all I
have is about 3 hertz, not kilohertz > > > > with the 22pf trimmer.
So when I try to adjust the carrier balance, in > > > > transmit, 7
db down the filter skirt, I have no adjustment. The > > carrier > > >
balance is .321mv on the low side and .634mv on the high side. It >
nulls > > > > out in the middle of the pot. This is why I think I'm not getting > > > > enough drive. Any thoughts? Thanks, Jerry K5LRU >
Paul Daulton K5WMS > > > > beacon WMS 185.302 khz
qrss30/slow 24/7 > > > > Jacksonville,Ar 72076 > > > > em34wu > > > >
[Non-text portions of this message have been removed] > > > >
[Non-text portions of this message
have been removed] > > > > > > > > > > > [Non-text portions of this
message have been removed] > Paul Daulton K5WMS beacon WMS 185.302 khz
qrss30/slow 24/7 Jacksonville,Ar 72076 em34wu
[Non-text portions of this message have been removed]
|
I'd really be suspicious of having a wrong value capacitor in the BFO circuit. Almost anything else would cause a small difference, not the big change you have.
Leonard
toggle quoted message
Show quoted text
--- In BITX20@..., "Paul Daulton" <k5wms@...> wrote:
Jerry I wonder if your xtal\s came with thie kit or you sourced them
some where else? Try swaping an xtal from filter with the bfo xtal.
Could the xtals be series resonant type? rather than parralell types?
Paul k5wms
Quoting jerryk5lru :
Arvid
I wound a 37-6 with fifty turns as per the calculator, worse. I shorted
the crystal and found I had moved lower to 6190. from the 8200. But
still had the 135 KC tunable range with the crystal shorted. I played
with the coil until I got it to the 9995. range with the crystal
shorted and still had 135 KC tuning range, when I removed the short it
went back to just a 5HZ tuning range.
--- In BITX20@..., arv wrote:
Jerry K5LRU
That indicates that your BFO oscillator should be tunable. Next step would
be to check capacitor and inductor values to make it tune across the crystal
frequency. You can change the inductor to a toroid core (T37-6 should work)
and adjust the turns until you get it to the right frequency. Toroid
calculator
located at can help with that task.
Arv K7HKL
_._
On 06/27/2013 10:59 PM, jerryk5lru wrote:
The crystal brand is KDS. I took your advice Arv and shorted the >
crystal out and the frequency tuned from 8104. MHz to 8239. Mhz 105
KC > range. But way lower than the 9995. Mhz area. Jerry K5LRU
--- In BITX20@... , arv > > wrote: > > > > > > Jerry
K5LRU > > > > > > The LC network in series with the crystal
(including series-C of the two > > > feedback divider caps) needs to
tune to the crystal frequency. Tuning > > > this resonant network a
bit above to a bit below the crystal frequency > > > is what pulls it
up or down. > > > > > > I would check the resonance components
associated with the crystal. > > > You might be able to get an idea
of what is going on by temporarily > > > soldering a very short wire
across the crystal to take it > > out-of-circuit. > > > Then check
the oscillator frequency. It should be close to the crystal > > >
frequency with the crystal shorted. Tuning range with the crystal > >
shorted will be more than with the crystal in-circuit, but this will > > tell > > > you if your tunable network really is tunable. >
Arv K7HKL > > > _._ > > > > > > On 06/27/2013 12:02 PM,
Paul Daulton wrote: > > > > > > > > > > > > > > > > What type and
brand of xtals are you using? > > > > > > > > Paul k5wms > > > > > >
Quoting jerryk5lru : > > > > > > > > This is a Bitx20 Version 3.
I'm almost done with it. The receiver > > > > receives good, the VFO
bandwidth is between 14,000. and 14,450. The > > > > exciter produces
a signal of 500mv and the PA kicks that up to > > around 4 > > > >
volts. When trying to tune the BFO and the carrier balance is where I
have the problem. My frequency is 9995.31 mhz at the emitter
of Q9. > > > > Here is where the problem starts. Leonards
instructions say I should > > > > have 15kc adjustment. But all I
have is about 3 hertz, not kilohertz > > > > with the 22pf trimmer.
So when I try to adjust the carrier balance, in > > > > transmit, 7
db down the filter skirt, I have no adjustment. The > > carrier > > >
balance is .321mv on the low side and .634mv on the high side. It >
nulls > > > > out in the middle of the pot. This is why I think I'm not getting > > > > enough drive. Any thoughts? Thanks, Jerry K5LRU >
Paul Daulton K5WMS > > > > beacon WMS 185.302 khz
qrss30/slow 24/7 > > > > Jacksonville,Ar 72076 > > > > em34wu > > > >
[Non-text portions of this message have been removed] > > > >
[Non-text portions of this message
have been removed] > > > > > > > > > > > [Non-text portions of this
message have been removed] > Paul Daulton K5WMS beacon WMS 185.302 khz
qrss30/slow 24/7 Jacksonville,Ar 72076 em34wu
[Non-text portions of this message have been removed]
|
Jerry I wonder if your xtal\s came with thie kit or you sourced them some where else? Try swaping an xtal from filter with the bfo xtal. Could the xtals be series resonant type? rather than parralell types? Paul k5wms Quoting jerryk5lru : Arvid I wound a 37-6 with fifty turns as per the calculator, worse. I shorted the crystal and found I had moved lower to 6190. from the 8200. But still had the 135 KC tunable range with the crystal shorted. I played with the coil until I got it to the 9995. range with the crystal shorted and still had 135 KC tuning range, when I removed the short it went back to just a 5HZ tuning range. --- In BITX20@..., arv wrote:
Jerry K5LRU
That indicates that your BFO oscillator should be tunable. Next step would
be to check capacitor and inductor values to make it tune across the crystal
frequency. You can change the inductor to a toroid core (T37-6 should work)
and adjust the turns until you get it to the right frequency. Toroid
calculator
located at can help with that task.
Arv K7HKL
_._
On 06/27/2013 10:59 PM, jerryk5lru wrote:
The crystal brand is KDS. I took your advice Arv and shorted the >
crystal out and the frequency tuned from 8104. MHz to 8239. Mhz 105
KC > range. But way lower than the 9995. Mhz area. Jerry K5LRU
--- In BITX20@... , arv > > wrote: > > > > > > Jerry
K5LRU > > > > > > The LC network in series with the crystal
(including series-C of the two > > > feedback divider caps) needs to
tune to the crystal frequency. Tuning > > > this resonant network a
bit above to a bit below the crystal frequency > > > is what pulls it
up or down. > > > > > > I would check the resonance components
associated with the crystal. > > > You might be able to get an idea
of what is going on by temporarily > > > soldering a very short wire
across the crystal to take it > > out-of-circuit. > > > Then check
the oscillator frequency. It should be close to the crystal > > >
frequency with the crystal shorted. Tuning range with the crystal > >
shorted will be more than with the crystal in-circuit, but this will > > tell > > > you if your tunable network really is tunable. >
Arv K7HKL > > > _._ > > > > > > On 06/27/2013 12:02 PM,
Paul Daulton wrote: > > > > > > > > > > > > > > > > What type and
brand of xtals are you using? > > > > > > > > Paul k5wms > > > > > >
Quoting jerryk5lru : > > > > > > > > This is a Bitx20 Version 3.
I'm almost done with it. The receiver > > > > receives good, the VFO
bandwidth is between 14,000. and 14,450. The > > > > exciter produces
a signal of 500mv and the PA kicks that up to > > around 4 > > > >
volts. When trying to tune the BFO and the carrier balance is where I
have the problem. My frequency is 9995.31 mhz at the emitter
of Q9. > > > > Here is where the problem starts. Leonards
instructions say I should > > > > have 15kc adjustment. But all I
have is about 3 hertz, not kilohertz > > > > with the 22pf trimmer.
So when I try to adjust the carrier balance, in > > > > transmit, 7
db down the filter skirt, I have no adjustment. The > > carrier > > >
balance is .321mv on the low side and .634mv on the high side. It >
nulls > > > > out in the middle of the pot. This is why I think I'm not getting > > > > enough drive. Any thoughts? Thanks, Jerry K5LRU >
Paul Daulton K5WMS > > > > beacon WMS 185.302 khz
qrss30/slow 24/7 > > > > Jacksonville,Ar 72076 > > > > em34wu > > > >
> > > >
[Non-text portions of this message
have been removed] > > > > > > > > > > > [Non-text portions of this
message have been removed] > Paul Daulton K5WMS beacon WMS 185.302 khz
qrss30/slow 24/7 Jacksonville,Ar 72076 em34wu
[Non-text portions of this message have been removed]
|
Jerry
Something really strange going on there. Do you have a different
crystal in the
same frequency range that could be substituted into the circuit?
Alternatively you might be able to build up a similar oscillator using
ugly-style
on a scrap of PCB and verify that your crystal can, or cannot, be
tuned. If you
don't reuse any L or C from the original circuit that would tell you if
the problem
is the crystal or one of the other components.
Since the IF filter crystals are the same frequency, it might be
possible to try one
of them in place of your present BFO crystal. Might prove something, or
might
not...?
The LC tuning mechanism can be changed from parallel to series, or
vice-versa,
to see if that makes a difference. My preference has always been to put
the L in
series with the C, and that in series with the crystal, but I have seen
it with the LC
network being parallel and that in series with the crystal. Both ways
usually seem
to work.
Arv
_._
toggle quoted message
Show quoted text
On 06/28/2013 10:49 AM, jerryk5lru wrote:
Arvid
I wound a 37-6 with fifty turns as per the calculator, worse. I
shorted the crystal and found I had moved lower to 6190. from the
8200. But still had the 135 KC tunable range with the crystal shorted.
I played with the coil until I got it to the 9995. range with the
crystal shorted and still had 135 KC tuning range, when I removed the
short it went back to just a 5HZ tuning range.
--- In BITX20@... <mailto:BITX20%40yahoogroups.com>, arv
<arvid.evans@...> wrote:
Jerry K5LRU
That indicates that your BFO oscillator should be tunable. Next step
would
be to check capacitor and inductor values to make it tune across the crystal
frequency. You can change the inductor to a toroid core (T37-6 should work)
and adjust the turns until you get it to the right frequency. Toroid
calculator
located at <> can help with that task.
Arv K7HKL
_._
On 06/27/2013 10:59 PM, jerryk5lru wrote:
The crystal brand is KDS. I took your advice Arv and shorted the
crystal out and the frequency tuned from 8104. MHz to 8239. Mhz
105 KC
range. But way lower than the 9995. Mhz area. Jerry K5LRU
--- In BITX20@... <mailto:BITX20%40yahoogroups.com>
<mailto:BITX20%40yahoogroups.com>, arv
<arvid.evans@> wrote:
Jerry K5LRU
The LC network in series with the crystal (including series-C of
the two
feedback divider caps) needs to tune to the crystal frequency.
Tuning
this resonant network a bit above to a bit below the crystal
frequency
is what pulls it up or down.
I would check the resonance components associated with the crystal.
You might be able to get an idea of what is going on by temporarily
soldering a very short wire across the crystal to take it out-of-circuit.
Then check the oscillator frequency. It should be close to the
crystal
frequency with the crystal shorted. Tuning range with the crystal
shorted will be more than with the crystal in-circuit, but this
will
tell
you if your tunable network really is tunable.
Arv K7HKL
_._
On 06/27/2013 12:02 PM, Paul Daulton wrote:
What type and brand of xtals are you using?
Paul k5wms
Quoting jerryk5lru :
This is a Bitx20 Version 3. I'm almost done with it. The receiver
receives good, the VFO bandwidth is between 14,000. and
14,450. The
exciter produces a signal of 500mv and the PA kicks that up to
around 4
volts. When trying to tune the BFO and the carrier balance is
where I
have the problem. My frequency is 9995.31 mhz at the emitter
of Q9.
Here is where the problem starts. Leonards instructions say I
should
have 15kc adjustment. But all I have is about 3 hertz, not
kilohertz
with the 22pf trimmer. So when I try to adjust the carrier
balance, in
transmit, 7 db down the filter skirt, I have no adjustment. The
carrier
balance is .321mv on the low side and .634mv on the high side. It
nulls
out in the middle of the pot. This is why I think I'm not getting
enough drive. Any thoughts? Thanks, Jerry K5LRU
Paul Daulton K5WMS
beacon WMS 185.302 khz qrss30/slow 24/7
Jacksonville,Ar 72076
em34wu
|
Arvid
I wound a 37-6 with fifty turns as per the calculator, worse. I shorted the crystal and found I had moved lower to 6190. from the 8200. But still had the 135 KC tunable range with the crystal shorted. I played with the coil until I got it to the 9995. range with the crystal shorted and still had 135 KC tuning range, when I removed the short it went back to just a 5HZ tuning range.
toggle quoted message
Show quoted text
--- In BITX20@..., arv <arvid.evans@...> wrote:
Jerry K5LRU
That indicates that your BFO oscillator should be tunable. Next step would
be to check capacitor and inductor values to make it tune across the crystal
frequency. You can change the inductor to a toroid core (T37-6 should work)
and adjust the turns until you get it to the right frequency. Toroid
calculator
located at <> can help with that task.
Arv K7HKL
_._
On 06/27/2013 10:59 PM, jerryk5lru wrote:
The crystal brand is KDS. I took your advice Arv and shorted the
crystal out and the frequency tuned from 8104. MHz to 8239. Mhz 105 KC
range. But way lower than the 9995. Mhz area. Jerry K5LRU
--- In BITX20@... <mailto:BITX20%40yahoogroups.com>, arv
<arvid.evans@> wrote:
Jerry K5LRU
The LC network in series with the crystal (including series-C of the two
feedback divider caps) needs to tune to the crystal frequency. Tuning
this resonant network a bit above to a bit below the crystal frequency
is what pulls it up or down.
I would check the resonance components associated with the crystal.
You might be able to get an idea of what is going on by temporarily
soldering a very short wire across the crystal to take it
out-of-circuit.
Then check the oscillator frequency. It should be close to the crystal
frequency with the crystal shorted. Tuning range with the crystal
shorted will be more than with the crystal in-circuit, but this will tell
you if your tunable network really is tunable.
Arv K7HKL
_._
On 06/27/2013 12:02 PM, Paul Daulton wrote:
What type and brand of xtals are you using?
Paul k5wms
Quoting jerryk5lru :
This is a Bitx20 Version 3. I'm almost done with it. The receiver
receives good, the VFO bandwidth is between 14,000. and 14,450. The
exciter produces a signal of 500mv and the PA kicks that up to
around 4
volts. When trying to tune the BFO and the carrier balance is where I
have the problem. My frequency is 9995.31 mhz at the emitter of Q9.
Here is where the problem starts. Leonards instructions say I should
have 15kc adjustment. But all I have is about 3 hertz, not kilohertz
with the 22pf trimmer. So when I try to adjust the carrier balance, in
transmit, 7 db down the filter skirt, I have no adjustment. The
carrier
balance is .321mv on the low side and .634mv on the high side. It
nulls
out in the middle of the pot. This is why I think I'm not getting
enough drive. Any thoughts? Thanks, Jerry K5LRU
Paul Daulton K5WMS
beacon WMS 185.302 khz qrss30/slow 24/7
Jacksonville,Ar 72076
em34wu
[Non-text portions of this message have been removed]
[Non-text portions of this message have been removed]
|
Jerry K5LRU
That indicates that your BFO oscillator should be tunable. Next step would
be to check capacitor and inductor values to make it tune across the crystal
frequency. You can change the inductor to a toroid core (T37-6 should work)
and adjust the turns until you get it to the right frequency. Toroid
calculator
located at <> can help with that task.
Arv K7HKL
_._
toggle quoted message
Show quoted text
On 06/27/2013 10:59 PM, jerryk5lru wrote:
The crystal brand is KDS. I took your advice Arv and shorted the
crystal out and the frequency tuned from 8104. MHz to 8239. Mhz 105 KC
range. But way lower than the 9995. Mhz area. Jerry K5LRU
--- In BITX20@... <mailto:BITX20%40yahoogroups.com>, arv
<arvid.evans@...> wrote:
Jerry K5LRU
The LC network in series with the crystal (including series-C of the two
feedback divider caps) needs to tune to the crystal frequency. Tuning
this resonant network a bit above to a bit below the crystal frequency
is what pulls it up or down.
I would check the resonance components associated with the crystal.
You might be able to get an idea of what is going on by temporarily
soldering a very short wire across the crystal to take it
out-of-circuit.
Then check the oscillator frequency. It should be close to the crystal
frequency with the crystal shorted. Tuning range with the crystal
shorted will be more than with the crystal in-circuit, but this will tell
you if your tunable network really is tunable.
Arv K7HKL
_._
On 06/27/2013 12:02 PM, Paul Daulton wrote:
What type and brand of xtals are you using?
Paul k5wms
Quoting jerryk5lru :
This is a Bitx20 Version 3. I'm almost done with it. The receiver
receives good, the VFO bandwidth is between 14,000. and 14,450. The
exciter produces a signal of 500mv and the PA kicks that up to
around 4
volts. When trying to tune the BFO and the carrier balance is where I
have the problem. My frequency is 9995.31 mhz at the emitter of Q9.
Here is where the problem starts. Leonards instructions say I should
have 15kc adjustment. But all I have is about 3 hertz, not kilohertz
with the 22pf trimmer. So when I try to adjust the carrier balance, in
transmit, 7 db down the filter skirt, I have no adjustment. The
carrier
balance is .321mv on the low side and .634mv on the high side. It
nulls
out in the middle of the pot. This is why I think I'm not getting
enough drive. Any thoughts? Thanks, Jerry K5LRU
Paul Daulton K5WMS
beacon WMS 185.302 khz qrss30/slow 24/7
Jacksonville,Ar 72076
em34wu
|
The crystal brand is KDS. I took your advice Arv and shorted the crystal out and the frequency tuned from 8104. MHz to 8239. Mhz 105 KC range. But way lower than the 9995. Mhz area. Jerry K5LRU
toggle quoted message
Show quoted text
--- In BITX20@..., arv <arvid.evans@...> wrote:
Jerry K5LRU
The LC network in series with the crystal (including series-C of the two
feedback divider caps) needs to tune to the crystal frequency. Tuning
this resonant network a bit above to a bit below the crystal frequency
is what pulls it up or down.
I would check the resonance components associated with the crystal.
You might be able to get an idea of what is going on by temporarily
soldering a very short wire across the crystal to take it out-of-circuit.
Then check the oscillator frequency. It should be close to the crystal
frequency with the crystal shorted. Tuning range with the crystal
shorted will be more than with the crystal in-circuit, but this will tell
you if your tunable network really is tunable.
Arv K7HKL
_._
On 06/27/2013 12:02 PM, Paul Daulton wrote:
What type and brand of xtals are you using?
Paul k5wms
Quoting jerryk5lru :
This is a Bitx20 Version 3. I'm almost done with it. The receiver
receives good, the VFO bandwidth is between 14,000. and 14,450. The
exciter produces a signal of 500mv and the PA kicks that up to around 4
volts. When trying to tune the BFO and the carrier balance is where I
have the problem. My frequency is 9995.31 mhz at the emitter of Q9.
Here is where the problem starts. Leonards instructions say I should
have 15kc adjustment. But all I have is about 3 hertz, not kilohertz
with the 22pf trimmer. So when I try to adjust the carrier balance, in
transmit, 7 db down the filter skirt, I have no adjustment. The carrier
balance is .321mv on the low side and .634mv on the high side. It nulls
out in the middle of the pot. This is why I think I'm not getting
enough drive. Any thoughts? Thanks, Jerry K5LRU
Paul Daulton K5WMS
beacon WMS 185.302 khz qrss30/slow 24/7
Jacksonville,Ar 72076
em34wu
[Non-text portions of this message have been removed]
[Non-text portions of this message have been removed]
|
Jerry K5LRU
The LC network in series with the crystal (including series-C of the two
feedback divider caps) needs to tune to the crystal frequency. Tuning
this resonant network a bit above to a bit below the crystal frequency
is what pulls it up or down.
I would check the resonance components associated with the crystal.
You might be able to get an idea of what is going on by temporarily
soldering a very short wire across the crystal to take it out-of-circuit.
Then check the oscillator frequency. It should be close to the crystal
frequency with the crystal shorted. Tuning range with the crystal
shorted will be more than with the crystal in-circuit, but this will tell
you if your tunable network really is tunable.
Arv K7HKL
_._
toggle quoted message
Show quoted text
On 06/27/2013 12:02 PM, Paul Daulton wrote:
What type and brand of xtals are you using?
Paul k5wms
Quoting jerryk5lru :
This is a Bitx20 Version 3. I'm almost done with it. The receiver
receives good, the VFO bandwidth is between 14,000. and 14,450. The
exciter produces a signal of 500mv and the PA kicks that up to around 4
volts. When trying to tune the BFO and the carrier balance is where I
have the problem. My frequency is 9995.31 mhz at the emitter of Q9.
Here is where the problem starts. Leonards instructions say I should
have 15kc adjustment. But all I have is about 3 hertz, not kilohertz
with the 22pf trimmer. So when I try to adjust the carrier balance, in
transmit, 7 db down the filter skirt, I have no adjustment. The carrier
balance is .321mv on the low side and .634mv on the high side. It nulls
out in the middle of the pot. This is why I think I'm not getting
enough drive. Any thoughts? Thanks, Jerry K5LRU
Paul Daulton K5WMS
beacon WMS 185.302 khz qrss30/slow 24/7
Jacksonville,Ar 72076
em34wu
|
Leonard
Raj vu2zap
F8VOA