Heavy Ironing a Viking II

[Jack-KA3ZLR-]

Afternoon Gents,

 Been pondering the Hi-Fi-ing another Vik-II, this time with heavy Iron Modified Heising.

I found some Iron I Like and wud like sum opinions...

On Peter Dahls Page there's a Mod Reactor at 50 Herny's 1500 v at .275A

On Hammonds Page there's a Hi-Fi Audio Output Tranny at 75 watt 5,000 I-IMP 213 Mils 4-8-16 usual secondary...Model number 1642SE.

Any Opinions...I'm Hopeing Steven will come in and have a say...

http://search.netscape.com/ns/boomframe.jsp?query=Hammond+Transformers&page=1&offset=1&result_url=redir%3Fsrc%3Dwebsearch%26requestId%3D2539fc2b2774c4ee%26clickedItemRank%3D2%26userQuery%3DHammond%2BTransformers%26clickedItemURN%3Dhttp%253A%252F%252Fwww.hammondmfg.com%252Fclaspg.htm%26invocationType%3D-%26fromPage%3DNSCPTop%26amp%3BampTest%3D1&remove_url=http%3A%2F%2Fwww.hammondmfg.com%2Fclaspg.htm

http://search.netscape.com/ns/boomframe.jsp?query=Peter+Dahl&page=1&offset=0&result_url=redir%3Fsrc%3Dwebsearch%26requestId%3Dc5a1a8708f0c25c6%26clickedItemRank%3D2%26userQuery%3DPeter%2BDahl%26clickedItemURN%3Dhttp%253A%252F%252Fwww.pwdahl.com%252Fham%252520catalog.htm%26invocationType%3D-%26fromPage%3DNSCPToolbarNS%26amp%3BampTest%3D1&remove_url=http%3A%2F%2Fwww.pwdahl.com%2Fham%252520catalog.htm

[k4kyv]

How would you  couple the audio to the final?  The Hammond unit looks
 like a conventional plate to voice coil output xfmr to me.

I searched thru the list but couldn't find the Dahl mod reactor, but from
 what you said, it should work ok.

You might consider doing what I did to my Eico 730 modulation xfmr that I
 use with the 10m rig.  

Take the stock Viking mod xfmr apart, remove the coil from the
 laminations, and restack the laminations like a power transformer, by
 alternating the direction of successive E - I combinations in the core
 assembly, thus eliminating the core gap.  In other words, restack the
 laminations so that the core is like that of a power transformer.

This will vastly increase the inductance of the windings by effectively
 increasing the volume of core material.  It will no  longer take DC thru
 the winding, because any DC will now saturate the core.  But with the
 mod reactor, you should have much greater low frequency response and
 less phase shift distortion.  The high frequency response of the
  transformer shouldn't be affected.

After the mods, using a 40H 120 ma mod reactor with the rebuilt xfmr, my
 Eico modulator now has a flat response of 20~ to 11,000~ measured.

[kc2ifr]

Jack, I used a Hammond 1650T on my Valiant, Modified Heising connected using a 10 H choke. Because of the low plate Z of the Valiant, the small choke works very good. Audio is very good.

On my Ranger, I use the Hammond 1642SE, no choke. The tranny will handle 213 mills of DC current.....way below what the ranger draws. I drive both rigs with a QSC solid state amp which will deliver about 600 watts of audio if needed but of course I dont need that much!!! But I believe in head room!!!
The Ranger is used to drive a GG 4-1000 amp on 160 and works very well. I had to reduce the output of the Ranger to about 20 watts for the 4x1. Both rigs sound great.

Bill

[Jack-KA3ZLR-]

My Idea with this one is to use Steves "Not So Dirty Path to Hi-Fii" on the AM Window, using the audio output tranny coupled through a 4uf  4x the B+ Cap to the Dahl Reactor no biggie was just Pondering some thoughts from yunns guys Thanks ...

[W1GFH]

re: Bill, KC2IFR, you are using a Hammond 1642SE in the Ranger, which at first I thought might be a drop-in substitute, but quickly realized you are doing a modified HUZ quick and not so dirty scheme, which I have always wanted to fool around with. Am I correct in assuming you are modulating the 6146 from the 5K primary side, and running the secondary to an 8 ohm hifi or PA audio amp? What did you do for neg feedback?

[Jack-KA3ZLR-]

Jack, I used a Hammond 1650T on my Valiant, Modified Heising connected using a 10 H choke. Because of the low plate Z of the Valiant, the small choke works very good. Audio is very good.

On my Ranger, I use the Hammond 1642SE, no choke. The tranny will handle 213 mills of DC current.....way below what the ranger draws. I drive both rigs with a QSC solid state amp which will deliver about 600 watts of audio if needed but of course I dont need that much!!! But I believe in head room!!!
The Ranger is used to drive a GG 4-1000 amp on 160 and works very well. I had to reduce the output of the Ranger to about 20 watts for the 4x1. Both rigs sound great.

Bill

Hi Bill,

 600 Watts, that sum awesum headroom ... I like the way you think...:grin:

[Steve - WB3HUZ]

It should work Jack. The Z of the VII final will be lower than 5k Ohms though. But since the primary has multiple taps, you should be able to find one that produces the best looking waveform and/or the largest positive modulation peaks. If Hammond has a tranny with a 3500 Ohm secondary or a dual 3500/5000 Ohms, get one of those.

[kc2ifr]

Hi again guys,
The 1642SE is BIG transformer....no way will it fit inside the ranger. And yes the 5K side is in the B+ to the 6146 plate and screen. Because of the power of the QSC, I drive the 16 ohm tap for the inpoot. All of this can be connected to the ranger thru the acc. plug on the back of the radio. Of course I also did the tim-tron mods first. Using my processing ahead of the QSC, the Valiant will do about 600 to 700 watts PEP outpoot and the ranger at full strap will do about 300 PEP. The Valiant needed all the padder caps in the outpoot replaced because of the very high voltages developed with that much audio. I do not use any feedback. The audio in both rigs is very clean unless I push them too hard!!!!
BTW.....the high PEP outoot is the result of asymetrical limiting I use in my processing chain.

[Jack-KA3ZLR-]

Well, maybe my thinking is to over kill...of course one can't be to safe in these matters...Maybe i shud try Bills setup there isn't a whole lot of difference between the valiant and vikII , but keeping the current and voltage passing levels heavy enough to with stand the duty cycle...is my main concern...with little effort...involved...

Is that Dahl 50 Henry reactor to much is what i'm wondering...I understand the Audio feed scheme now, of course my thinking the heavier the better Reactor wise...mod/current/saturation of the iron...

Once this is settled then the three Diode Limiter questions i have...

[W1GFH]

Hm...I have a Stancor 75w A3808 Pri. 3800 ohms and sec. 10,7,5, and 4K ohms that might fit my lil' Ranger. Anyone know the stock Ranger mod transformer's impedance?

[W2JBL]

sold my Ranger years ago but i think the stock mod transformer had about a 6K secondary. now as to Jack's Viking II- the stock iron is actually a pretty good unit. i'd leave it in place,and just put modified Heising around it. i did this for years on my 32V2, and am currently doing it with my ART-13, on which it made a huge improvement. i'm using about 40 henries of reactor, consisting of a couple old 10H .450A chokes, and the secondary of a 2500v center tapped 300 mil plate transformer all in series. the audio goes through a 8MFD 660AC motor starting cap (very hammy!). i have thought about doing this to my Viking II also, but never seem to get around to it- it sounds good with just basic mods.

[Jack-KA3ZLR-]

Gentlemen,

 Welp, i ordered up a couple of the Hammond Trannys, I think i'll do some investigating, and see what transpires with the "Hi-Fi" Broadcast series.

 Pretty bad the Best i can come up with is four weeks shipping... I called Digi-Key and Mouser...SO i'm going to have to wait a little bit...  I think I'll hold on the Dahl transformers till I see what appreciable Gain i come up with...

Thanks for the help....

[xe1yzy]

Gentlemen,

 Welp, i ordered up a couple of the Hammond Trannys, I think i'll do some investigating, and see what transpires with the "Hi-Fi" Broadcast series.

 Pretty bad the Best i can come up with is four weeks shipping... I called Digi-Key and Mouser...SO i'm going to have to wait a little bit...  I think I'll hold on the Dahl transformers till I see what appreciable Gain i come up with...

Thanks for the help....

Great Jack , please let us now about yours conclusions!, I have a Viking II waiting for restoration

[WA1GFZ]

Save your nads and go PDM with no iron.