EMRFD Message Archive 1419

Message Date From Subject
1419 2008-02-06 17:11:41 sp9mrn H-mode mixer questions

Hi, I'm thinking 'bout making a H-mode mixer and I've some questions.

1. What is REAL difference in squarer if I use 74HC86 instead of
74AC86 at HF bands, IF 9MHz, max VFO freq. abt 40MHz. Will I see a
difference or not?

2. what is best schematics to use 4:1 transformers from coilcraft. Or
coilcraft is bad idea?

Thanks in advance
73
MAc

1426 2008-02-10 13:49:22 Giancarlo Re: H-mode mixer questions

Hi Mac,

please see my comments

1427 2008-02-10 13:58:49 brainerd@wildblue... Re: H-mode mixer questions

On 10 Feb 2008 at 21:49, Giancarlo wrote:

> > 1. What is REAL difference in squarer if I use 74HC86 instead of
> > 74AC86 at HF bands, IF 9MHz, max VFO freq. abt 40MHz. Will I see a
> > difference or not?
>
> The ideal is the 74AC86 as it has very low delay and propagation times
> respect the 74HC86 at least 10x better. This will permit better
> complementary 50-50 switching waveforms
>

There is also the 74AHC86 which is faster and cheaper than the 74AC86.

Dave - WB6DHW
<http://wb6dhw.com>

1428 2008-02-10 14:28:36 sp9mrn Re: H-mode mixer questions

Gian Thank's for comments.
I have been thinking abut HC and coilcraft transformes, because I
have it in my box :-) and it's easy to mahe a quick try.

Of course I know PA site and of course Yours. Inthe fact - Your
article in QST was a motivation to thinh about H-mode.

I also think about frontend - and made a try - making 80m cauer based
on your design -
http://sp-qrp.pl/modules.php?name=Content&pa=showpage&pid=37

So thanks also for ideas ;-)
Do You plan to publish something new?

MAc
sp9mrn

1419	2008-02-06 17:11:41	sp9mrn	H-mode mixer questions
Message	Date	From	Subject
Hi, I'm thinking 'bout making a H-mode mixer and I've some questions. 1. What is REAL difference in squarer if I use 74HC86 instead of 74AC86 at HF bands, IF 9MHz, max VFO freq. abt 40MHz. Will I see a difference or not? 2. what is best schematics to use 4:1 transformers from coilcraft. Or coilcraft is bad idea? Thanks in advance 73 MAc
1426	2008-02-10 13:49:22	Giancarlo	Re: H-mode mixer questions
Hi Mac, please see my comments
1427	2008-02-10 13:58:49	brainerd@wildblue...	Re: H-mode mixer questions
On 10 Feb 2008 at 21:49, Giancarlo wrote: > > 1. What is REAL difference in squarer if I use 74HC86 instead of > > 74AC86 at HF bands, IF 9MHz, max VFO freq. abt 40MHz. Will I see a > > difference or not? > > The ideal is the 74AC86 as it has very low delay and propagation times > respect the 74HC86 at least 10x better. This will permit better > complementary 50-50 switching waveforms > There is also the 74AHC86 which is faster and cheaper than the 74AC86. Dave - WB6DHW <http://wb6dhw.com>
1428	2008-02-10 14:28:36	sp9mrn	Re: H-mode mixer questions
Gian Thank's for comments. I have been thinking abut HC and coilcraft transformes, because I have it in my box :-) and it's easy to mahe a quick try. Of course I know PA site and of course Yours. Inthe fact - Your article in QST was a motivation to thinh about H-mode. I also think about frontend - and made a try - making 80m cauer based on your design - http://sp-qrp.pl/modules.php?name=Content&pa=showpage&pid=37 So thanks also for ideas ;-) Do You plan to publish something new? MAc sp9mrn