EMRFD Message Archive 6850

Message Date From Subject
6850 2011-11-18 18:56:42 vlfun2 Hycas IF/455KHz
has anyone here used the little Hycas IF kitlet at 455Khz IF?

is there an easy way to search this site for info on this question or for info on past discussions concerning work on or with the amp? appreciate any help at all. thanks.

Dave
6851 2011-11-19 00:36:43 Ashhar Farhan Re: Hycas IF/455KHz
Are you going to use it with mechanical filters? Their impedance is
reactive. You will have to develop a matching network.
The gain could be enough to sustain oscillations, you might want to
eliminate the load inductors.
- farhan

On 11/18/11, vlfun2 <vlfun2@yahoo.com> wrote:
> has anyone here used the little Hycas IF kitlet at 455Khz IF?
>
> is there an easy way to search this site for info on this question or for
> info on past discussions concerning work on or with the amp? appreciate any
> help at all. thanks.
>
> Dave
>
>

--
Sent from my mobile device
6852 2011-11-19 14:32:28 vlfun2 Re: Hycas IF/455KHz
thank you for the reply farhan I appreciate receiving this. not sure what I try next but maybe using it at 9MHz to see if it's functioning or not. I have some crystal filters for 9 so will give it a try.

Dave

6853 2011-11-19 19:20:03 kb1gmx Re: Hycas IF/455KHz
6860 2011-11-22 15:14:03 vlfun2 Re: Hycas IF/455KHz
thanks very much Allison. I was given info on the existing hyscas as built that it would perform ok at 455Khz which it didn't. my first thoughts were much larger inductances as well but not wishing to offend anyone I posted the question anyway. thanks for confirming my very first thoughts. I did build the entire amp dead-bug with all the same parts with only the changes in: no L1, L2-3-4 I subbed 3.9mH and wound an FT37-J for T1. the amp then worked fine at 455Khz although not optimum by a mile or more. I'll keep experimenting. I'm only going to post one more questi
6862 2011-11-22 21:24:38 john lawson Re: Hycas IF/455KHz
Dave, if the Hycas IF/455 does not work out and you still want to use the 455 KHz filter,,,,I'm guessing it's might be a Collins filter.....Doug DeMaw built 2 receivers with the Collins filters with some CA3028A's in the IF....this was in the late 70's if I recall correctly......one filter had a 2000 ohm termination in and out  for one of the receivers and the other filter had a termination of 100K in and out for the other receiver. I built both of them "back in the day" and they seemed to work FB.....If you desire more information later, let me know. Mouser has the transformers that are needed between the IC's and I can give you their part number also....BTW I have built and used the Hycas IF strip and it worked absolutely beautiful with my 9 MHz crystal filter........John K5IRK


________________________________
6865 2011-11-23 09:30:00 kb1gmx Re: Hycas IF/455KHz
6869 2011-11-23 20:07:17 vlfun2 Re: Hycas IF/455KHz
outstanding John. I recognize the call. very kind reply. yes collins is correct. I bought a box of them a lot of years back in all the bandwidths available at the time. just thought it would be fun to use some of them. I am familiar with the IF/AGC stages you listed as I have a lot of the ARRL Handbooks and many others. I also have a handful of the CA3028s just in case. be very glad to have the Mouser numbers you used. I received 2 sets of Krystall Engineering 9MHz filters from a fellow in Israel a couple days ago. if I wasn't clear on this before the Hycas I completed with the kitlet is full up 9MHz and operational. just a matter of connecting a few simple things and running the Hycas as I'm sure it was intended. it will be fine. thanks very much John.

Dave

6870 2011-11-23 21:11:28 vlfun2 Re: Hycas IF/455KHz
I was very happy getting confirmation you gave earlier and working on calculating the new values but my pesky job is always in the way of having fun. Now it looks like you've finished the work for me and well ahead of my schedule. soon as the turkey wears off tomorrow I'll solder in all your values here and fire the ugly versi
6872 2011-11-24 04:42:02 john lawson Re: Hycas IF/455KHz
Dave, Good morning and Happy Thanksgiving.....Per your request, the Mouser number for the 30,000/500 ohm transformer is 42IF102-RC for the 455 KHz transformer. I believe DeMaw used 3 of them in each of the receivers. At $1.07 each, you might want to order a few extras...hope this helps.....good luck on the modified Hycas project....John 



________________________________
6888 2011-11-25 13:48:58 vlfun2 Re: Hycas IF/455KHz
John I am really smiling now. I have 10 brand new ones on hand. I'll have hot soldering pencil shortly. many thanks Mr. the shove in the right directi
6893 2011-11-25 17:47:16 vlfun2 Re: Hycas IF/455KHz
fantastic John. the hycas amp is awesome at 455Khz using 3 of the 42IF102 transformers. temporarily there is a small cylindrical ferrite potted 3.3mH inductor in for L4. mouser 434-02-332J. studying the Hycas board I believe I can make a good job of drilling it for the mouser transformers. I probably should menti
7029 2011-12-15 19:17:10 vlfun2 Re: Hycas IF/455KHz
this old thread probably long dead and gone now but having just found this I wanted to thank you again for the excellent tech support. I was successful with the 455KHz Hycas project using Collins mechanical filter but just received a few sets of KVG crystal filters I posted for info a bit ago. being 9MHz filters I believe the original and working 9MHz Hycas amp already built is the way to go as everyone probably was in agreement
7031 2011-12-16 09:58:06 steve white Re: Hycas IF/455KHz
Dave



I too want to use the HYCAS at 455Khz, can you be specific about what parts
values you changed please. I am hombrewing a receiver where I plan on using
the HYCAS if I can.



Steve NU0P







_____

7033 2011-12-16 17:06:25 Craig Smith Hycas IF/455KHz
I am also working on a project that utilizes the hycas at 455 KHz. Could those answering Steve also copy me or the entire list?

Thanks and 73
… Craig AC0DS


> I too want to use the HYCAS at 455Khz, can you be specific about what parts
> values you changed please. I am hombrewing a receiver where I plan on using
> the HYCAS if I can.
>
> Steve NU0P
>

Craig Smith
1009 Alder Way
Longmont, CO 80503
craig@powersmith.net
303-834-7712



>



[Non-text portions of this message have been removed]
7034 2011-12-16 17:43:55 kb1gmx Re: Hycas IF/455KHz
If you use the web interface versi
7036 2011-12-17 16:47:06 vlfun2 Re: Hycas IF/455KHz
Hi Steve. so far I am having good success with Mouser's 42IF102 IF transformers. the first ugly construction with those little cans is working well and is fed from a Collins mechanical filter into the first stage omitting the inductor/cap. right to the 2K gate resistor. I tried wiring the cans in both directions from center tap for supply input and looking down on a can laying flat on the double sided PCB, primary pins to your left and output pair to right and pins all looking at you, the center pin is DC feed and the top pin is the collector. I don't have the spec sheet in front of me to number the pins for you but if you connect each stage this way it will work fine. if you connect the collector to the bottom pin oscillations take over. you can add some resistance across the outer two primary pins but it broadens their tuning. some might not hurt. I also used the final can to feed the PNP dif/amp bases biasing the left base entirely and taking the detector output off the first collector and using the outside PNP for a product detector just as done on the Hycas except for the different wiring/biasing done on the board. the trio tune up very easily and have been completely stable. I'm studying the extra PCB I purchased for a drilling plan to mount the same Mouser IF cans directly to the board. I'll post something when I figure out the best solution. best of luck. if you look on Mouser for this IF can they have a pin-out for them. I'm leaving right at this moment but will post the pin numbers when I get back tonight.

Dave
7037 2011-12-17 21:44:24 vlfun2 Re: Hycas IF/455KHz
Steve the Mouser 42IF102 pins are 3: collector, 2, center-pin DC supply and pin 1 unused or put some 10K or more across if any stability problems. use pins 2 and 4, secondary, as output and maybe adjust gate bias resistor value for better match. good luck.

Dave

7044 2011-12-18 20:36:13 steve white Re: Hycas IF/455KHz
Thanks so much Dave, I am sure that lots of others will benefit from your
work along with inputs from everyone else.



Steve





_____

7051 2011-12-19 13:12:40 vlfun2 Re: Hycas IF/455KHz
I was told about using this Mouser transformer a ways back in this thread and happened to have them on hand in good quantity. comparing an older Mouser catalog with today's I see a few of the cans are already gone and I'll bet the rest will go one day soon as well. If you're not squemish about rewinding with #40 enamel wire you can do an awful lot with these little cans. RF double tuned filters, adjustable L-matching inductors using fixed value caps impedance mods as well as frequency mods. you can also replace the tiny dog-bone caps internally or externally across the primary or suitable small caps can be inserted to alter the frequency response in any of the cans. only your imagination will limit your use and a range of a few microhenries up to a little more than 680uH is handily available. possibly more if the slug can still clear the coil. this is a lot easier to do than write about. you can use a vice or a goodly sized piece of used PCB. solder one pin opposite the side you are modifying to hold the disassembled bobbin out in the open away from the PCB. if the mod is less inductance cut the wire lead on pin 3 and start unwinding counting turns if you are keeping much of the primary or peel it all off and wind your own primary and or secondary. the number of turns are listed in the spec sheets as well as any capacitor. #40 is not difficult to work with new and you have the process of removal to observe for replacing a new winding. remember the secondary is the first winding on the core so if you need to change it do it before winding a new primary. tin well by heating and removing the enamel before wrapping on pins to solder. if you have no inductance or DC continuity you don't have a connection to one pin or the other. observe winding direction and when done reassemble and test. they actually are a snap to do and just over a buck each really handy. all the best.

Dave

> Thanks so much Dave, I am sure that lots of others will benefit from your
> work along with inputs from everyone else.
>
>
>
> Steve
>
>
>
>
>
> _____
>
>