Looking for Mohawk Mods

[ve1hd]

I am working on a recently acquired Heathkit Mohawk. I see references to mods for the Mohawk but I have not been able to find any. Does anyone have mods for this receiver ? Does anyone know if they are available online ?
Thans in advance ...

[K7NCR]

I purchased the copies of ER for that radio series. Reasonable price. But, would it be allowable to post some scans on this site? Would we need permission from ER magazine? I could make the scans. Anyone have thoughts?
Norm K7NCR

[W2XR]

I have a Mohawk as well. In my opinion, it is one of the prettiest receivers ever made (along with the Apache and Marauder transmitters that I also own); in my mind, it evokes the 2-tone color scheme of a '57 Chevy. You know, that classic turquoise and white color combination. This is not surprising, as a lot of the Heathkit "Indian-series" equipment debuted in 1958, and was no doubt modeled on the industrial design and popular styling of the time. Like my Apache and SB-10 SSB adaptor, my Mohawk has the chrome-plated knobs that were used on the last production of this classic equipment. Very cool looking.

At any rate, it is also my opinion that it is one of the worst HF communications receivers ever made. Drifty, susceptible to front-end and IF overload (ever wonder why Heath put the IF gain control on the front panel??), poor AGC, terrible audio, etc. The mods suggested in the ER article are probably worthwhile, but I'm leaving mine stock. Currently my Mohawk is a shelf-queen that graces W2XR Studio 3.

The "user-receivers" here at W2XR are the SP-600, the R-390A, and the 75A-4. They all literally run circles around the Mohawk insofar as performance goes, which is entirely unsurprising, considering the price differential, etc. . But none of them hold a candle to the Mohawk in the sexy looks department.

Good luck with your Mohawk, the 1957 Chevy of amateur radio receivers!

73,

Bruce

[w3jn]

Posting copyrighted material on any forum is a no-no unless you received the permission from the copyright holder.

I doubt whether ER would grant such permission; the owner is a businessman, and I don't think the small price for back issues he charges is unreasonable at all.

IIRC it was a 3-part article as there were plenty of mods to be made.

I too was disgusted with one I briefly had and sold it very quickly for all the reasons Bruce stated.

[ve1hd]

The challenge of doing the mods are part of the exercise. If one wants plug and play one simply goes to the store and buys a ready made box and goes home and plugs it in.
Maybe the receiver is a real piece of junk, but then again maybe it is worth the effort. I want to do the latter.
I am not trying to get someone to break the rules of business. Just asking if anyone had the list of mods for the RX-1. Maybe there will be some and maybe there won't.
In any case thanks in advance.....

[w3jn]

It has a lot of potential, that's for sure.   If you've a mind to attack it, go for it!!

[K7NCR]

Hey ALL!
Here is the response of received:

Dear Norm,
With all due respect, I am going to decline your offer at this time.

Electric Radio is a small operation, and sales of back issues is a
 large
part of our business. We have a considerable investment in maintaining
 an
inventory of back issues, and in reprinting them. It is copyright
 material
that is not public domain.

73,
Ray Osterwald, NØDMS
Electric Radio Magazine

Of course I agree with his thoughts on this. It was really easy and reasonably priced to get the back issues involved, 11/97, 12/97, and 1/98. Not to mention the ton of other interesting items to look at in those issues besides the Mohawk mods. So, for now, everybody will have to do what I did and pony up the cash for the reprints.
I have done most of the mods written about in this series, and they do make a marked improvement in the way this radio plays. The only mod left is the drift correction. Honestly, when I leave the Mohawk on over my 3 day weekends, it settles down a lot after the first few hours on. I have found some temp compensating disc caps in my junk jars, and have to figure out what I need yet to purchase. I did fine a couple of sources for these  caps on the WWW.
My most immediate issue is audio output. It is fairly low level, even though the headphone output will blast you out. I tried a speaker in that jack in case the circuit was miss-wired, but had the same result. I will probably find a nice tube "hi-fi" mono amp and feed that for audio.
Boy, the 5KC pass position sure makes the AM AND SSB boys sound good!
I'm getting thru the diag on the NC-300, it is working a lot better now. Just have to get the #3 ball-chain link for the dial drum finished and installed. I still need to try to match the cabinet paint, will drag some samples to Wally World, or a BigBox hardware store to match up.
73!
Norm K7NCR

[ve1hd]

Thanks Norm, I do appreciate your trying.

One of these days I may just go at the thing on my own. I have noticed a couple of areas where there could be impovements. Should I do that I will share the info with the group here. I am not happy with the AVC in the receiver. Maybe some work in the area of the 6BJ7 would be in order.

 My receiver seems to have plenty of audio out. Actually it seems to have a walloping amount. Since it has the old standby, 6AQ5 for an audio output tube it is unlikely the tube is shot. I do notice a bypass cap in the cathode circuit. Might be worthwhile to take a look at it.

Have you ever had to clean tarnished silver contacts such as those in the tube sockets ? If so what did you use ? I am tempted to change them all but would certainly like to try cleaning them first.

Thanks again Norm .....

[Todd, KA1KAQ]

DeOxit works pretty well, Clarence. Shoot a little on with the spray can nozzle on 'low' or use a Q-Tip, etc to drizzle a little on, then installed and remove the tube a few times to aid in the cleaning. You could do each one separately, but what a pain!

I agree with your thoughts on pursuing this, it makes sense since you picked up the set. Some of the folks responding to this thread have first hand knowledge of the receiver and its 'issues', time and desire tend to shape opinions on the value of such an exercise. But as John says, if you're up for it, give it a go. Even if the results don't end up being everything you hope for, at least the undertaking is a positive experience, being done for the right reasons.

Looking forward to the next time we meet up on the air. I enjoy working you, Dave, Donovan and the rest of the VE gang on 80M during the week. Most nights you're the only AM activity down there. Dave's talking about possibly dropping the BIG vertical due to aviation regs, we need to help him find a way to save it.

[ve1hd]

Thanks Todd. I will do something with the receiver. I don't expect it to become a Racal or an R-390. Just a receiver that matches my Apache.
Yes Dave should be encouraged to keep the big tower if he can. Too bad he could not get someone to shorten it to 99 feet. That way he would not have to worry about the tower lighting. Along with being a real pain to replace they are also expensive to keep powered these days. Just thought of something... maybe he would get away with using those high efficency flourescent bulbs.
I have not hear him for a few days... Maybe he is working...
Thanks Todd...

[Steve - WB3HUZ]

Don't feel bad. I contacted the ARRL over ten years ago to scan and post a few AM related articles first published in QST in the 1950s. They said no.

Hey ALL!
Here is the response of received:

Dear Norm,
With all due respect, I am going to decline your offer at this time.

Electric Radio is a small operation, and sales of back issues is a
 large
part of our business. We have a considerable investment in maintaining
 an
inventory of back issues, and in reprinting them. It is copyright
 material
that is not public domain.

73,
Ray Osterwald, NØDMS
Electric Radio Magazine

Of course I agree with his thoughts on this. It was really easy and reasonably priced to get the back issues involved, 11/97, 12/97, and 1/98. Not to mention the ton of other interesting items to look at in those issues besides the Mohawk mods. So, for now, everybody will have to do what I did and pony up the cash for the reprints.
I have done most of the mods written about in this series, and they do make a marked improvement in the way this radio plays. The only mod left is the drift correction. Honestly, when I leave the Mohawk on over my 3 day weekends, it settles down a lot after the first few hours on. I have found some temp compensating disc caps in my junk jars, and have to figure out what I need yet to purchase. I did fine a couple of sources for these  caps on the WWW.
My most immediate issue is audio output. It is fairly low level, even though the headphone output will blast you out. I tried a speaker in that jack in case the circuit was miss-wired, but had the same result. I will probably find a nice tube "hi-fi" mono amp and feed that for audio.
Boy, the 5KC pass position sure makes the AM AND SSB boys sound good!
I'm getting thru the diag on the NC-300, it is working a lot better now. Just have to get the #3 ball-chain link for the dial drum finished and installed. I still need to try to match the cabinet paint, will drag some samples to Wally World, or a BigBox hardware store to match up.
73!
Norm K7NCR

[ve1hd]

Hi Steve, thanks for the reply. Yes organizations devoted to Ham Radio tend to get like that. I am not disappointed and I appreciate Norms efforts. One day I may order the back issues. It is not a life threatening situation. And as I said I may just take a deep look at it myself.
It is an interesting piece of equipment and I certainly don't want to modify it too much. After all I would not want to redesign it or remanufacture it as then it would not be a "Mohawk"

Thanks ...

Clarence ... VE1HD

[Pete, WA2CWA]

Don't feel bad. I contacted the ARRL over ten years ago to scan and post a few AM related articles first published in QST in the 1950s. They said no.

If you want them up on the ARRL AM web page, contact Ed Hare. I believe Ed made the offer years ago if we wanted any additional QST AM related articles on the page.

[Steve - WB3HUZ]

Most or all of the ones I wanted are now up on the ARRL AM TIS page (hmmm, what a coincidence). Years ago, I was looking to add them to the Tech section of The AM Window Web Site.

Don't feel bad. I contacted the ARRL over ten years ago to scan and post a few AM related articles first published in QST in the 1950s. They said no.

If you want them up on the ARRL AM web page, contact Ed Hare. I believe Ed made the offer years ago if we wanted any additional QST AM related articles on the page.

[ve1hd]

Thanks Steve, I looked there last evening but I could not find the postings you mentioned. Maybe sometime if you have a moment you might drop me a link to the page.

Thanks again ... Clarence ... VE1HD

[Steve - WB3HUZ]

http://www.arrl.org/tis/info/am.html