?

Ken,

Ive noticed the same thing about the bassy audio, i was going to change some cap values to see if i could improve it. Ill let you know how it comes out.

Joel KB6QVI

On Nov 23, 2016, at 4:55 PM, Ken Chase chase8043@... [BITX20] <BITX20@...> wrote:

?

I've finally hooked up a 5351 to the Bitx40. In testing I noticed two things(not related to the 5351)

The audio is very 'bassy' sounding. Is there some way to improve the quality or does the BFO have to be moved slightly?

As I tune the vfo from the lower end of the band and up, the closer I get to the end of the band, signal ?strength drops. Is this due to the BPF?

73

Ken VA3ABN.

?

mike,
is your meter showing milliamps or millwatts? 900ma is just about right.

On 27-Nov-2016 4:55 am, "Mike Haynes mike.haynes08@... [BITX20]" <BITX20@...> wrote:

?

I replaced the transistor I destroyed (Q13) with a 2N3904. Everything seems to be working. The ammeter is only showing 700 or so milliwatts with the loud "HAAAALOOO." It's a cheap multimeter though, so with everything in the circuit checking out okay, I'm beginning to wonder if I'm just chasing ghosts?

On Fri, Nov 25, 2016 at 3:21 PM, riggerswa@... [BITX20] <BITX20@...> wrote:

?

Nope no nothing :(

Im back at work now for 2 weeks i work away from home for 2 weeks then home for 1?

When i get back i will have another look

--

Mike Haynes

?

Pardon but,
2P being power our or power in?

?

Mark. K3MRK

Either 10K or 100K, or anything in between, will work fine for the

tuning pot.? A 10-turn type pot makes tuning much easier if you

have one available.?

Resistors for decreasing heat generation are 220 ohms.

Arv? K7HKL
_._

On Sat, Nov 26, 2016 at 8:56 PM, 'Mark W' k3mrk1@... [BITX20] <BITX20@...> wrote:

?

No I did not receive any resistors. What size are they? I’ll try to find some. I also noticed that my tuning pot is 10k. The board info on the website says it should be 100k. Which is correct?

I have received my enclosure and am almost done installing.

Mark

K3MRK

?

?

From: BITX20@... [mailto:BITX20@...]
Sent: Thursday, November 24, 2016 8:48 PM
To: BITX20@...
Subject: Re: [BITX20] Bitx 40 board.

?

?

mark,
you must have received a strip of 220 ohm resistors in the pack. if you replace the 100 ohm emitter resistors of the six amps with these, the drift will drastically reduce. the details are on the blog.
- f

On 25-Nov-2016 4:58 am, "Mark Walton k3mrk1@... [BITX20]" <BITX20@...> wrote:

>?

> ?
>
> It might be worse since there is no enclosure at all. Maybe not really warming up at all. I'm hoping the enclosure itself will have some heat retention. There are some transistors that can be used as heaters. I'll wait till I get the enclosure and see how it is. I realize that this circuit is prone to some drift on warm-up, but I think mine may be excessive. Bad cap? I haven't really started digging in yet. I have all the parts for a DDS and may just go that way from the start. I'm no engineer and will have to figure out how that is done as well.
> Mark
> K3MRK
>
>
> On Nov 24, 2016 4:21 PM, "Thomas Noel tnoel@... [BITX20]" <BITX20@...> wrote:

>>?

>> ?
>>
>> What would happen if you added an intentional heater to the enclosure? I'm thinking of something like the flat stick-on pads used to warm reptile tanks, stuck on the underside of the radio enclosure? Thinking a giant version of an oven controlled crystal oscillator?
>>
>> Tom
>> KF7RSF
>>
>> Sent from my iPhone
>>
>> On Nov 24, 2016, at 12:53, Mark Walton k3mrk1@... [BITX20] <BITX20@...> wrote:
>>

>>> ?

>>>
>>> I recently received my BitX-40 board. Until I get the enclosure, I only hooked it up for receive. Worked right out of the box. The only issues I've found is the drift is pretty bad even after being powered up for an hour. What should I be looking at to try to improve the stability? I do plan to build a DDS VFO for it over the winter.
>>> The only other issue is the running is very touchy. I have coming a multiturn pot to fix that.
>>> Any ideas on the drift?
>>> Other than that , I'm very happy with the board and look forward to building onto it in the near future.
>>> Thanks
>>> Mark. K3MRK
>
>
>

?

No I did not receive any resistors. What size are they? I’ll try to find some. I also noticed that my tuning pot is 10k. The board info on the website says it should be 100k. Which is correct?

I have received my enclosure and am almost done installing.

Mark

K3MRK

?

?

From: BITX20@... [mailto:BITX20@...]
Sent: Thursday, November 24, 2016 8:48 PM
To: BITX20@...
Subject: Re: [BITX20] Bitx 40 board.

?

?

mark,
you must have received a strip of 220 ohm resistors in the pack. if you replace the 100 ohm emitter resistors of the six amps with these, the drift will drastically reduce. the details are on the blog.
- f

On 25-Nov-2016 4:58 am, "Mark Walton k3mrk1@... [BITX20]" <BITX20@...> wrote:

>?

> ?
>
> It might be worse since there is no enclosure at all. Maybe not really warming up at all. I'm hoping the enclosure itself will have some heat retention. There are some transistors that can be used as heaters. I'll wait till I get the enclosure and see how it is. I realize that this circuit is prone to some drift on warm-up, but I think mine may be excessive. Bad cap? I haven't really started digging in yet. I have all the parts for a DDS and may just go that way from the start. I'm no engineer and will have to figure out how that is done as well.
> Mark
> K3MRK
>
>
> On Nov 24, 2016 4:21 PM, "Thomas Noel tnoel@... [BITX20]" <BITX20@...> wrote:

>>?

>> ?
>>
>> What would happen if you added an intentional heater to the enclosure? I'm thinking of something like the flat stick-on pads used to warm reptile tanks, stuck on the underside of the radio enclosure? Thinking a giant version of an oven controlled crystal oscillator?
>>
>> Tom
>> KF7RSF
>>
>> Sent from my iPhone
>>
>> On Nov 24, 2016, at 12:53, Mark Walton k3mrk1@... [BITX20] <BITX20@...> wrote:
>>

>>> ?

>>>
>>> I recently received my BitX-40 board. Until I get the enclosure, I only hooked it up for receive. Worked right out of the box. The only issues I've found is the drift is pretty bad even after being powered up for an hour. What should I be looking at to try to improve the stability? I do plan to build a DDS VFO for it over the winter.
>>> The only other issue is the running is very touchy. I have coming a multiturn pot to fix that.
>>> Any ideas on the drift?
>>> Other than that , I'm very happy with the board and look forward to building onto it in the near future.
>>> Thanks
>>> Mark. K3MRK
>
>
>

?

I set my bitx 40 up with DDS VFO. The DDS VFO is spot on frequency. I set the IF off set to -12MHZ. The radio seams to be off frequency. Looks like about 1.5 kc. And the transmite is different then receive frequency. Did I set the IF out set wrong? Should I try to adjust the IF some how? I see parts missing for any IF adjustments.

Thanks

Bill N3JHS

?

I replaced the transistor I destroyed (Q13) with a 2N3904. Everything seems to be working. The ammeter is only showing 700 or so milliwatts with the loud "HAAAALOOO." It's a cheap multimeter though, so with everything in the circuit checking out okay, I'm beginning to wonder if I'm just chasing ghosts?

On Fri, Nov 25, 2016 at 3:21 PM, riggerswa@... [BITX20] <BITX20@...> wrote:

?

Nope no nothing :(

Im back at work now for 2 weeks i work away from home for 2 weeks then home for 1?

When i get back i will have another look

--

Mike Haynes

?

Joe

On my board the VFO oscillator is Q-9 and VFO buffer is Q-8.? You would

use a small value capacitor (27 pf...?) from Q8 emitter to your frequency

counter.??

The junction of C-72, R80, and emitter of Q-8 is the proper place.? This can
be located by holding your PCB with the PA heatsink on the left edge and
starting with the base (lower left) of Q-7 ( Q-7 is just below the K1 relay, near the
top-center of the board).? Follow the trace downward past R71 (marked"222"),
then down to the right end of C-72.? The other end (left end) of C-72 has a
thru-hole connection to a bottom side trace that goes to the emitter of Q-8.?
That thru-hole is your connection point for a coupling capacitor to your

frequency counter.

Arv? K7HKL
_._

On Fri, Nov 25, 2016 at 1:47 PM, Baruch Atta baruchatta@... [BITX20] <BITX20@...> wrote:

?

Ashar

It would be nice to have a thru hole that can be used for a wire to measure the bfo frequency.? Or is there already one ?? I can't find it on mine.? The on-line instructions say to take the reading off of the collector of Q6, but Q6 is a surface mount device, and hard to get a grip with the aligator clip. ?

73, Joe

On Thu, Nov 24, 2016 at 10:11 PM, Ashhar Farhan farhanbox@... [BITX20] <BITX20@...> wrote:

?

the board actually another infineon varactor smd diode instead of the mv209. so, dont be alarmed to see it missing!

On 25-Nov-2016 8:35 am, "Ken Chase chase8043@... [BITX20]" <BITX20@...> wrote:

?

Setup your DDS for 5MHZ - 4.7 MHZ to cover 7MHZ - 7.3MHZ.

73

Ken VA3ABN

On Thu, Nov 24, 2016 at 9:56 PM, mikeyancey@... [BITX20] <BITX20@...> wrote:

?

Fortunately I had a MV209 'non-smd' handy, and I tacked it in place.
RX's well now; no TX 'til I can setup better to test.

VERY nice. Although, nothing in the region right now for 40m.

Although I'll take advantage of the optional DDS tap, what is the approximate
VFO Range? Does it START at 5.00 Mhz (for approximately LSB 7.000) and go DOWN
to 4.800 Mhz?

Although, for DDS, I suppose our range would be for a bit more than a tuning diode can give,
say... 5.00 Mhz down to 4.700 Mhz.

I notice that the mounting points (and standoffs) are isolated from the Ground Plane (ground ref?),

is there a reason for that?

Mike Yancey, KM5Z
Dallas, Texas USA

?

Nope no nothing :(

Im back at work now for 2 weeks i work away from home for 2 weeks then home for 1?

When i get back i will have another look