Title: Help with mating an HP-23A power supply to the MT-1 Cheyenne Post by: AF9J on May 19, 2007, 10:27:34 PM Hi Everybody,
I've been working on the Cheyenne today. So far it seems to be in OK shape. More than anything else, it's dusty from a lack of use (I did some preliminary cleaning inside of it to get rid of the worst of the dust). I've wired up the 6-pin Cinch Jones for the transmitter end. Now I have to to wire up the 11 pin plug (thanks John for the plug! :) ) on the HP-23A end of things. This is where it gets a little weird for me. The Cheyenne is normally wired to work as a slave (powerwise) to the Commanche receiver. Steps are listed for working around this, so you can use the Cheyenne with other receivers (basically you bridge between Pin 6 [which is a ground], and Pin 4 [which controls the power supply voltage]). The 11 pins on the HP-23A are as follows: Pin 1 -130V bias Pin 2 Fil. Common Pin 3 + LV Pin 4 + HV Pin 5 Not connected Pin 6 12V filament voltage Pin 7 Ground Pin 8 6V filament voltage Pin 9 AC switch Pin 10 AC Common Pin 11 Adjustable Bias OK, Now I know have to connect on the transmitter end from Pin 5 (the Filament) to Pin 6 on the HP-23A for filament power (no it's not Pin 8 like I expected, because checking my Cheyenne out, showed it was wired for 12V filament power [done by using a 5W, 11 ohm resisitor as a voltage divider {the manual shows how to wire it for either 6 or 12V filament voltage}]). I know that Pin 1 (the 300V, Low Voltage supply) on the Cheyenne end, goes to Pin 3 on the HP-23A end. I also know that Pin 2 (the 600V High Voltage supply for the 6146 final) on the Cheyenne, goes to Pin 4 on the HP-23. OK, now this is where I worry about making a visit to Zorchland. 1. I have TWO different ground points listed for the Cheyenne's pins. Pin 3 and Pin 6. I only have ONE ground shown on the HP-23A (pin 7). I'm not sure if one ground is for the filaments, and one ground is for the final. So, I'm a bit leery about wiring both of them up to Pin 7 of the HP-23A power supply. Is the one listed as Ground on the power supply for the filaments, and do I take the other ground to one of the bias pins on the power supply? 2. The HP-23A does about 820V for its high voltage. I was told that you can bring it down to 600V, by adjusting the bias control. So, would I run one of the grounds, to Pin 11 on the HP-23A (the Adjustable Bias)? 3. Pin 4 on the Cheyenne is shown as being the Power Supply Control line on the pin diagram on the back of the Cheyenne (so the Comanche can control ON/OFF power from the supply). BUT, in the manual, it lists Pin 4 as being for a relay. Do I just ignore Pin 4, or is it needed to run the internal antenna relay, and/or supply voltage for the receiver standby relay (in the receiver)? If I can't ignore it, what pin do I wire it up to on the HP-23A power supply? I know some of you have used Cheyennes in the past. Maybe you've encountered these issues. What did you do to resolve them? Thanks for any input you can provide. 73, Ellen - AF9J Title: Re: Help with mating an HP-23A power supply to the MT-1 Cheyenne Post by: W1RKW on May 20, 2007, 01:32:56 PM Ellen,
1. Pin 3 and Pin 6 are common to each other on the Cheyenne. You can use either or both without zorching as far as ground goes. 2. I downloaded the HP23A schematic. Looking at it I don't believe you will be able to lower the B+ per sè using the adjustable bias control. Using that control may allow you to adjust the bias current to the 6146 allowing you to use the 800VDC B+. And if that is the case you will need to modify the Cheyenne to run a bias line to the 6146 from the power supply unit. Then you can use pin 3 or pin 6 as a dedicated bias pin by removing the ground connection at either one of those pins. One or the other pin will then be ground only. Someone will have to chime in on this one as I'm not sure exactly how to run the Cheyenne at 800VDC. 3. The Cheyenne schematic shows both pin 4's on both connectors as being connected together with no other connections elsewhere within the rig. Also, the original power supply schematic appears to not use pin 4. I don't know if this is a misprint or what. It doesn't make sense. Yet this pin 4 connection is used to interface the RCVR to the XMTR. The Commanche receiver schematic shows pin 4 as being the on-off switch via the audio level control. Maybe one of my manuals are missing some information or I have an earlier Cheyenne in comparison to your Cheyenne. I'm sure this can be done easily with the PS you have. Just need the right info. Bob 1. I have TWO different ground points listed for the Cheyenne's pins. Pin 3 and Pin 6. I only have ONE ground shown on the HP-23A (pin 7). I'm not sure if one ground is for the filaments, and one ground is for the final. So, I'm a bit leery about wiring both of them up to Pin 7 of the HP-23A power supply. Is the one listed as Ground on the power supply for the filaments, and do I take the other ground to one of the bias pins on the power supply? 2. The HP-23A does about 820V for its high voltage. I was told that you can bring it down to 600V, by adjusting the bias control. So, would I run one of the grounds, to Pin 11 on the HP-23A (the Adjustable Bias)? 3. Pin 4 on the Cheyenne is shown as being the Power Supply Control line on the pin diagram on the back of the Cheyenne (so the Comanche can control ON/OFF power from the supply). BUT, in the manual, it lists Pin 4 as being for a relay. Do I just ignore Pin 4, or is it needed to run the internal antenna relay, and/or supply voltage for the receiver standby relay (in the receiver)? If I can't ignore it, what pin do I wire it up to on the HP-23A power supply? I know some of you have used Cheyennes in the past. Maybe you've encountered these issues. What did you do to resolve them? Thanks for any input you can provide. 73, Ellen - AF9J Title: Re: Help with mating an HP-23A power supply to the MT-1 Cheyenne Post by: WQ9E on May 20, 2007, 07:20:25 PM Hi Ellen,
You might also want to download the schematic for the HP-20 "utility" supply which was designed for the mobile twins. It uses a similar transformer to that of the HP-23A but derives both the high and medium voltage from a single winding. What you might consider following is the way the voltage doubler is set up to provide 600 volts in this supply. It uses a pair of smaller 40 uf capacitors as the input to the filter and then connects the 125 uf units through 100 ohm series resistors. Although your HP-23A transformer voltage is a little higher than that of the HP-20, using the 2 stage filter with smaller input capacitors will yield a voltage far closer to the design value for the Cheyenne. The previous poster's comments about bringing the variable bias voltage to the Cheyenne to compensate for increased final plate voltage is also very important to follow. 73, Rodger WQ9E Title: Re: Help with mating an HP-23A power supply to the MT-1 Cheyenne Post by: AF9J on May 20, 2007, 07:41:13 PM OK, I have a thought. I've used 6146Bs in in my Kenwood TS-820 at about 800 or 900V in the HV circuit. I have a couple of them laying around here. If I remember rightly, the 6146B has about 40 or 50% higher plate dissipation power capability (and as a result, a bit more output power) than the 6146, or 6146A (my Cheyenne is using a 6146). Might it possibly just be easier to rebiase the Cheyenne for 800V, so I can run 6146Bs? Besides, I could use more omph as it is, and the 6146B is a more common tube.
73, Ellen - AF9J Title: Re: Help with mating an HP-23A power supply to the MT-1 Cheyenne Post by: WQ9E on May 20, 2007, 08:00:20 PM Hi Ellen,
The 6146 itself should have no problem with 800 or so volts on the plate since the Cheyenne is controlled carrier AM so you won't have any plate voltage increase under modulation. I don't have my Cheyenne schematic handy but I don't recall that the final plate voltage goes through any switches or relays so the usual suspects for breakdown under a slight voltage increase are not there. There have been reports of problems with instability and neutralization problems when using the B or W variants of the 6146 in rigs designed for the original tube but I have never experienced any problem and I am using B's in one of my Valiants and W's (the vacuum tube not the dim bulb) in my other Valiant without any problems. My reference to the HP-20 schematic was just if you wished to run the original voltage on your Cheyenne and I think that you will have no problem using the HP-23A as is as long as you do provide a bias adjustment. I believe the Cheyenne was rated for 90 watts either phone or CW and you probably don't want to push that limit much due to heating inside the rig. For future consideration, the 1 KW class of linear amplifiers (SB-200/HA-10/FL-2100B etc.) work great with controlled carrier AM rigs. 73, Rodger WQ9E Title: Re: Help with mating an HP-23A power supply to the MT-1 Cheyenne Post by: WZ1M on May 20, 2007, 09:26:23 PM Could it be that the 820 volt supply is at no load and will drop to about 780 when under full load?
Title: Re: Help with mating an HP-23A power supply to the MT-1 Cheyenne Post by: WQ9E on May 20, 2007, 09:56:57 PM Actually closer to 750 under full load as I recall from my SB-102 but you are right Gary, I imagine about 780 under the lighter load of the Cheyenne. Of course this is greatly dependent upon the health of the filter caps and the actual line voltage but still considerably higher than the ~600 volts originally specified for the Cheyenne.
Rodger WQ9E Title: Re: Help with mating an HP-23A power supply to the MT-1 Cheyenne Post by: WU2D on May 20, 2007, 10:31:33 PM HI Ellen,
I agree. I think the HP-23 will work great on that rig without fooling with it since it does not have the greatest regulation anyway. You may not need to fool with the bias at all. And try the 6146B - It will probably work great. I used one of these supplies on my old NCX-3 that I had in college and it was solid, even when bad things happened like the main relay getting stuck! Mike WU2D Title: Re: Help with mating an HP-23A power supply to the MT-1 Cheyenne Post by: AF9J on May 20, 2007, 11:16:23 PM You guys are so cool! So, in other words, I only need to connect up one of the grounds (I also noticed in the schematic that both grounds seemed to be common), to the HP-23A ground at Pin 7, the Low Voltage line to Pin 3, on the HP-23A, the High Voltage line to Pin 4 on the HP-23A, and the Filament line to Pin 8 on the HP-23A. Hmmmm, in other words I didn't need to solder up the other two lines (the one for theON/OFF control of the power supply from the Comanche [which I don't have], and one of the gorunds)?
OH well, maybe I should clip those two wires short. I'm done with the transmitter end of the power cable. I just need to finish up the power supply end. BTW, yes, I've heard of issues with neutralizing 6146Bs and 6146Ws, with some rigs that were designed around the 6146 & 6146A. Well, it's late. I'd better get some sleep. Just one last time, I only need to hook up 4 of the 6 lines I soldered? It may sound stupid, but I'm just trying to play it safe. The last time I rushed through an electronics job, I made a mistake that was a bit of a hassle to repair. 73 & Good Night (4:30 AM comes early for me), Ellen - AF9J Title: Re: Help with mating an HP-23A power supply to the MT-1 Cheyenne Post by: w3jn on May 21, 2007, 06:52:07 AM As I've posted previously, I've had no problems whatsoever running a Cheyenne with a stock HP-23.
Title: Re: Help with mating an HP-23A power supply to the MT-1 Cheyenne Post by: AF9J on May 21, 2007, 07:05:43 AM Good morning John,
Did you only need to hook up 4 of the 6 wires that are ordinarily hooked up to the Cheyenne? Ellen - AF9J Half done with the power cable Title: Re: Help with mating an HP-23A power supply to the MT-1 Cheyenne Post by: w3jn on May 21, 2007, 07:27:12 PM As I recall, 5 conductors. Fil, bias, B+, final plate, and ground. Some HP-23s have an on/off switch, others dont so you hafta short the 110 lines coming out of the PS (was meant so turning on the radio actually turned on the PS. I wouldn't do this wiht the Cheyenne though).
Title: Re: Help with mating an HP-23A power supply to the MT-1 Cheyenne Post by: K1MVP on May 22, 2007, 12:29:19 AM BTW, yes, I've heard of issues with neutralizing 6146Bs and 6146Ws, with some rigs that were designed around the 6146 & 6146A. Well, it's late. Hi Ellen, I have had "issues" trying to neutralize 6146`s in an old Knight T-150 transmitter,--what a real "pain". But then again, I had problems neutralizing my homebrew 6L6 xmtr,--ya never know. 73, Rene, K1MVP P.S, How is the "96" working out for you? Title: Re: Help with mating an HP-23A power supply to the MT-1 Cheyenne Post by: AF9J on May 22, 2007, 07:21:41 AM Good morning John,
I was wondering if the bias had anything to do with it. My problem is that there is no specified bias line from the Cheyenne. Here is the pin out from the Cheyenne power plug: Pin 1 - 300V LV feed Pin 2 - 600V High Voltage feed (from what everybody says I'm oK with the 820V no load off the HP-23A Pin 3 - Ground Pin 4 -Relay/On & Off power supply control feedthrough to the Comanche (to use it for On & Off power supply switching) NOT USED in my case. Pin 5 - Filament Voltage (in my case 12V, since that's what it's wired for) Pin 6 - Ground First of all I assume I would hook up to the Adjustable Bias feed from the HP-23A. But, what do I use to feed the bias?, one of the Grounds (since the Bias is basically nothing more than a DC offset from Ground anyway)? 73, Ellen - AF9J As I've posted previously, I've had no problems whatsoever running a Cheyenne with a stock HP-23. Title: Re: Help with mating an HP-23A power supply to the MT-1 Cheyenne Post by: w3jn on May 22, 2007, 10:44:06 AM I thought the CHeyenne needed a bias supply. Guess my memory isn't correct. If it doesn't need it, don't connect it ;)
Title: Re: Help with mating an HP-23A power supply to the MT-1 Cheyenne Post by: AF9J on May 22, 2007, 12:36:46 PM Okee doke. Thank you! Well, back to work for me. I'm going to finish wiring up Ms. Cheyenne after work. Then it's smoke test time (sorry, but yours truly doesn't have a Variac).
73 & have a good day, Ellen I thought the CHeyenne needed a bias supply. Guess my memory isn't correct. If it doesn't need it, don't connect it ;) Title: Re: Help with mating an HP-23A power supply to the MT-1 Cheyenne Post by: KB2WIG on May 22, 2007, 12:40:50 PM "doesn't have a Variac)." series up a 100 watt lamp in the 120 v line ...it will drop the voltage and also act as a fuse..... its a little better than nothing....... klc
Title: Re: Help with mating an HP-23A power supply to the MT-1 Cheyenne Post by: AF9J on May 22, 2007, 12:47:12 PM Hi Rene,
The SX-96 is The Bomb for me. It hears AM so much better than the receiver in my FT-897D. I would have never been able to check into the Midwest Vintage Net without it, two weeks ago. It works great. Thanks for selling it to me. :) As for the 6146Bs - yeah, I'm aware of neutralization issues when using it with some of the older rigs from the 50s and early 60s. It was an issue of discussion last year in the Kenwood Hybrids group I belong to. Basically, the 6146B is markedly different from the 6146, and 6146A tubes. So much so, that some Collins, and Heathkits have gone into runaway parasitics, and nuked themselves. I guess I was hoping that with the B's higher plate dissipation power, I could weasel a few extra watts out of the Cheyenne. I have two Chinese 6146Bs sitting around (that I got soaked for $55 from AES last year), that are basically useless in my Kenwood TS-820, due to the fact that its very high plate voltage (900 volts), literally caused the filaments to flash over, as soon as I turned them on, giving me the opportunity to make repairs in the High Voltage board. But at the lower voltage the Cheyenne runs at, they may be useable. If not, does anybody here have a use for them? 73, Ellen - AF9J BTW, yes, I've heard of issues with neutralizing 6146Bs and 6146Ws, with some rigs that were designed around the 6146 & 6146A. Well, it's late. Hi Ellen, I have had "issues" trying to neutralize 6146`s in an old Knight T-150 transmitter,--what a real "pain". But then again, I had problems neutralizing my homebrew 6L6 xmtr,--ya never know. 73, Rene, K1MVP P.S, How is the "96" working out for you? Title: Re: Help with mating an HP-23A power supply to the MT-1 Cheyenne Post by: AF9J on May 22, 2007, 12:51:09 PM Yeah I have one of those. I made it last year. We use them in the Kenwood hybrids group to provide a load, and save the power transformer, while doing repairs. I should have thought about using it. Thanks for the reminder KC. :)
73, Ellen - AF9J "doesn't have a Variac)." series up a 100 watt lamp in the 120 v line ...it will drop the voltage and also act as a fuse..... its a little better than nothing....... klc Title: Re: Help with mating an HP-23A power supply to the MT-1 Cheyenne Post by: W1RKW on May 22, 2007, 05:11:14 PM I use the ole light bulb in series trick for a lot of things, especially for troubleshooting and testing. I have a collection of light bulb wattages for various situations. My range is 25w to 200w depending on what I'm testing. I start off small and work up to big to a certain point. It's mostly feel.
Also using other 6146's other than the ones designed for the circuit can also introduce parasitics besides neutralization problems. Yeah I have one of those. I made it last year. We use them in the Kenwood hybrids group to provide a load, and save the power transformer, while doing repairs. I should have thought about using it. Thanks for the reminder KC. :) 73, Ellen - AF9J "doesn't have a Variac)." series up a 100 watt lamp in the 120 v line ...it will drop the voltage and also act as a fuse..... its a little better than nothing....... klc Title: Re: Help with mating an HP-23A power supply to the MT-1 Cheyenne Post by: The Slab Bacon on May 23, 2007, 08:09:08 AM FWIW: 6146, 6146A, and 6146W are all interchangable and will work just fine. However the 6146B is somewhat a different animal. It not only has a little more dissipation, but it is designed a little differently.
It is really best suited for AB1 service as a leenyour amplifryer for SSB service. It has a different screen grid structure and wants a higher screen voltage to produce a little more gain in amplifier service with less drive. I have also seen them used as class C amplifiers and drivers that were NOT modulated. they do have different interelectrode capacitance values than the standard versions. This may explain some of the neutralizing / parasitic problems. "B"s will work fine in some AM rigs and not in others. It is totally dependent on the final circuit and operating parameters of the individual transmitter. The Slab Bacon Title: Re: Help with mating an HP-23A power supply to the MT-1 Cheyenne Post by: AF9J on May 23, 2007, 10:00:36 AM Cool Frank,
I'll have to check out the schematic to see. But in the meantime, if anybody has a need, or a use for a couple of Chinese 6146Ws badged as Penta Labs, let me know. As of right now, the tubes have been sitting in their boxes for a year, gathering dust. 73, Ellen - AF9J Title: Re: Help with mating an HP-23A power supply to the MT-1 Cheyenne Post by: W1RKW on May 24, 2007, 03:40:17 PM Then there's the ole elusive 6293.
Ellen, have you been able to put the fire to the wire yet? Title: Re: Help with mating an HP-23A power supply to the MT-1 Cheyenne Post by: The Slab Bacon on May 24, 2007, 04:15:41 PM Then there's the ole elusive 6293. Ah Yes........... the good old pulse rated 6146 which will usually work just about anywhere you'd use a regular 6146, but no one knows about them and you can usually find them for $1 at hamfests ;D ;D Title: Re: Help with mating an HP-23A power supply to the MT-1 Cheyenne Post by: AF9J on May 24, 2007, 04:44:30 PM Hi Bob,
I just have to finish soldering up the power supply end of the cable. I was going to do it yesterday, but I had such a lousy day (frankly the whole week was lousy), and I was so burned out, I just vegged out, and went to bed early. I didn't get any further than stripping the wires. I plan on doing it tonight. I took tomorrow as a vacation day, so hopefully (if everything behaves), I'll be able to give it a test run tomorrow. I've heard of the 6293. Becuse it's meant for pulse service, and all of the stress pulse transients can cuase, it's supposed to VERY sturdy. Oh, and don't for get the 12V version - the 6883. There are suppsoed to be a ton of them around from the old Motorola Motracs, going for peanuts. 73, Ellen - AF9J Then there's the ole elusive 6293. Ellen, have you been able to put the fire to the wire yet? Title: Re: Help with mating an HP-23A power supply to the MT-1 Cheyenne - no joy Post by: AF9J on May 25, 2007, 07:19:31 PM I finished wiring it up last night. Fired it up, and - nothing. I checked all of my connections, and they're fine. Then I checked the power supply manual, and it seems like I have to wire a jumper between Pins 9 & 10 since I don't seem to really have AC power feed control (to the power supply), from the rig So, I did that, and still, no luck. Oh well, I guess for the 10,000th time, I get to find out the hard way what's wrong with a radio.
73, Ellen - AF9J Title: Re: Help with mating an HP-23A power supply to the MT-1 Cheyenne Post by: kf6pqt on May 25, 2007, 09:14:18 PM Crap!
I'm watching this thread as I've got a Cheyenne on its way to me as well. I need another screen-modulated heathkit no more than I need an extra hole in my head, but hey, it was cheap, and its got a VFO, so i can do AM outside the window. -Jason kf6pqt Title: Re: Help with mating an HP-23A power supply to the MT-1 Cheyenne Post by: WU2D on May 26, 2007, 03:49:33 PM Ellen,
Have you verified that is the supply ON and working (with a meter)? Do you have fillaments lit up yet? Mike Title: Re: Help with mating an HP-23A power supply to the MT-1 Cheyenne Post by: W1GFH on May 26, 2007, 03:58:34 PM The Heathkit Cheyenne should be outlawed! Too many people waste too much time fussing to get a PW signal on the air! ::) ;D OK, I'm kidding, but Jason I don't know if you have heard WA6JUS from South Bay on the air with his Cheyenne lately, it is sounding good but barely copyable. IMO, these rigs were meant not as fixed stations, but to allow AMers to go mobile, a worthy cause.
Title: Re: Help with mating an HP-23A power supply to the MT-1 Cheyenne Post by: AF9J on May 26, 2007, 04:08:11 PM Yup Mike,
I checked that. I a friend of mine (who called me to say hi), who used to be a ham, and worked as an RF tech for a defense contractor, and used to have an SB101, told me to run a resistance check on the primary winding of the power supply, with the plug in (it has the jumper for the AC power switch), and that it should be near 8 ohms. I got 5.8 ohms, so it's fine. But guess what? It was off handedly mentioned that the filament voltage is AC. THAT threw me for a loop. I thought it was DC!! So my ground on the power supply is for the LV & HV B+, which are DC. The filament ground is the FILAMENT COMMON on the power supply. This also explains why I had no lit up dial lamps. They probably run off of the filament supply. So, I have to use BOTH Cheyenne grounds. I was also told that there's a dirty little secret about Heathkit power supplies, they run floating grounds. Go figure. I'm wiring up the filament ground as I write this (besides, condx. on the bands are lousy, so I'm taking a break from doing the WPX CW). I'll let you know in a little while, if that did the trick. Ellen - AF9J Title: Re: Help with mating an HP-23A power supply to the MT-1 Cheyenne Post by: AF9J on May 26, 2007, 04:29:43 PM Fine and dandy Joe,
But, remember not all of us live in (or can afford) houses with nice big yards. So we're stuck with being in apartments. As a result, that means not being able to run 100 or 200w of carrier, without risking getting into your neighbors' loser, consumer electronics devices. It's bad enough when it's quacking SSB, but when they can hear every work your saying - that's trouble in the making. Sure it's a pain to use low power and marginal antennas on the low bands, but on 20 & above, it isn't too bad. That's one of the reasons I've been checking out 10 & 6 so much lately. Remember, there's more to ham radio that 160, 75 & 40 meters. I wish I could get more people to try 20, 15, & 10m AM when the bands are open. I know many, if not most of you hate QRP. But I work both coasts with monotonous regularity on 5W with SSB, on 20, 15, and 10. So, 25W of AM carrier is plenty on 20 & above when condx. are good. Also, you can still have a decent QSO, without sounding like a version of the VOA. If a person wants to, hey cool. But, I didn't get into ham radio to let out my inner broadcaster. There, I really don't feel like debating. Wiring changes have been made. I'm going to give it a try. 73, Ellen - AF9J The Heathkit Cheyenne should be outlawed! Too many people waste too much time fussing to get a PW signal on the air! ::) ;D OK, I'm kidding, but Jason I don't know if you have heard WA6JUS from South Bay on the air with his Cheyenne lately, it is sounding good but barely copyable. IMO, these rigs were meant not as fixed stations, but to allow AMers to go mobile, a worthy cause. Title: Re: Help with mating an HP-23A power supply to the MT-1 Cheyenne Post by: W4FCC on May 26, 2007, 07:28:45 PM Well said! :)
Rick W4FCC Title: Re: Help with mating an HP-23A power supply to the MT-1 Cheyenne - Success! Post by: AF9J on May 26, 2007, 08:58:59 PM Hi Everybody,
Sorry this took so long. I fired up the Cheyenne after I added the filament ground wire. Guess what. It didn't work!! Ugh!! In disgust I put things away, and decided to check things out tomorrow. Besides, I had laundry to do. Just as I was about to carry my laundry to the laundromat in the basement of my apartment building, the friend I mentioned a couple of postings back (who turned me on to the fact that the filamament is AC, and that I'd need a filament ground), called to ask how things went. I said, not too good. So, the laundry was put down, and over the phone we went through the power supply, and then the Cheyenne. The power supply checked out as OK (so at least I didn't get sold a bill of goods by Mr. ePay Power Seller). Since I was getting no filaments or freq. display lamps (which are run off of the filament voltage) at all, we traced the filament circuit, and I did continuity checks. By all rights, it was concluded that the filaments should be fine. That left only one thing - the multifunction switch on the front panel, that turns the radio on & off, and selects the mode. It was possible that it was oxidized. I turned it through its movement a dozen times or so, plugged in the power cable I'd made, turned on the power supply, turned on the radio, and wouldn't you know it, IT WORKED!! The lamps lit, and the filaments came on in all of the tubes for the first time in umpteen years! Yeah!! My friend then told me that some of the earlier Heathkits have a design flaw - the filament voltage (and as a result, the power on function) runs right through the rotary function switch. This switch is not as sturdy electrically or mechanically, as the typical rocker or toggle switch you use for these functions, so there are potential reliability issues. I'll do some more work on the Cheyenne tomorrow (I still have to do laundry). I might fire it up for a few hours, and let things settle/burn in, since the radio has sat unused for so long. I'll have to get some Caig De-oxit to clean out that switch some more. Jason, if you need a copy of the Cheyenne manual, and/or want to know what I did to wire it up, let me know. In essence, you're using 5 of the 6 pins on the power plug. Thanks for all of your input people. With the exception of the finals on my Kenwood TS-820, and guitar amps, I'm in unfamiliar territory with regards to tubes. Most of my experience is in solid state. Please forgive me if my questions are stupid, and my frustration shows. 73, Ellen - AF9J Title: Re: Help with mating an HP-23A power supply to the MT-1 Cheyenne Post by: K1MVP on May 26, 2007, 09:35:20 PM The Heathkit Cheyenne should be outlawed! Too many people waste too much time fussing to get a PW signal on the air! ::) ;D OK, I'm kidding, but Jason I don't know if you have heard WA6JUS from South Bay on the air with his Cheyenne lately, it is sounding good but barely copyable. IMO, these rigs were meant not as fixed stations, but to allow AMers to go mobile, a worthy cause. These PW rigs are IMO a good way for a new person to start to get experience with AM. "jumping into" a 500 to 1000 watt transmitter can be looking for trouble(also my opinion). There is also a real "easy" or "simple' way to increase the power outpoot or give it a "kick in the pants",-- just feed the PW rig into a good linear, an Ameritron, an Heathkit SB-200, or 220 or anything similar, and ya can get 150 to 250 watts out with only 10 t0 15 watts into the amp. 73, K1MVP P.S,Ellen, AF9J, Good job fixin your problems,(mating the HP-23 to the Cheyenne,--By the way these problems can occur with ANY rig, be it homebrew, older commercial (high or low power) etc. What gets me is, after I may have restored an older rig,(homebrew or commercial) and I get it to function great,--I may put it on the shelf for a period of time(6 months to a year) and I decide to "fire it up" again, and it will develop a problem just sittin on the shelf, for no good reason, and back it has to go on the bench.(welcome to the world of BA`s) Title: Re: Help with mating an HP-23A power supply to the MT-1 Cheyenne Post by: kf6pqt on May 26, 2007, 09:37:21 PM Cool, glad it works!
Mine hasn't shown up yet. Already have the manuals from BAMA. I've also got a Heathkit transistorized 12v mobile supply, that should add to the fireworks. Joe, I'm collecting mobile rigs for a reason... ;) Ground breaking begins on the 2x 811a amp this weekend. And for fixed station 6m, I scored a really beat Heathkit Seneca (2x 6146) at TRW this morning for $20! -Jason kf6pqt Title: Re: Help with mating an HP-23A power supply to the MT-1 Cheyenne Post by: AF9J on May 26, 2007, 09:49:13 PM Hi again people,
Laundry is in the washing machines, and I have some spare time. Jason - an Andy Jackson for a Seneca? Whoah! What are you going to use for a receiver? WHen I can get the scratch, I'm hoping to get my hands on an old Clegg. Rene - yeah, isn't that something, Old Man Murphy sure does strike, when you let stuff sit. What a pain! I almost feel that way now, that I shut off the Cheyenne. It's like, what's next? 73, Ellen - AF9J Title: Re: Help with mating an HP-23A power supply to the MT-1 Cheyenne Post by: kf6pqt on May 27, 2007, 12:16:23 AM Oops, thats right, its only a transmitter... I'm used to my Gonset G50 which is both... Have to give that some thought, I'm sure my NC-300 is stone deaf up that high.
I do have a little solid state comverter-thing called a Tunaverter that downconverts 6m to 1500kc, sooo, maybe an ancient hollow-state Galvin (proto-Motorola) car radio? Title: Re: Help with mating an HP-23A power supply to the MT-1 Cheyenne Post by: AF9J on May 27, 2007, 02:01:58 PM Jason,
You could always do the reverse of what I'm doing until I bring the Cheyenne on line. I'm using a transceiver (in this case, my FT-897D) for the transmitter, and the SX-96 for the receiver. Use your G-50 for the receiver, and your Seneca for the transmitter. Besides, the Seneca probably has a bit more oomph then the G-50. If you use the converter/AM radio combination, you'll probably desense them, when you transmit with the Seneca, since they more than likely don't have a Standby function, receiver gain controls, or receiver mute capability. Your G-50 probably has at least receiver gain control, and power standby, so at the very least, you can sort of use this setup without maving to modify receiver internals, to prevent nuking the receiver. You won't have PTT capability, but it will still be usuable, until you get a receiver that's better matched to the Seneca. Otherwise, use your NC-300. To overcome its deafness on 6 (which was pretty common on most VHF receivers, until well into the late 70s, or early 80s), use a receive preamp. 73, Ellen - AF9J Title: Re: Help with mating an HP-23A power supply to the MT-1 Cheyenne Post by: KB2WIG on May 27, 2007, 03:03:25 PM " sure my NC-300 is stone deaf up that high. "
A MPF 102 can be jay essed into the front end , after the first set of tuned ckts. Its got a high value Z into the devise so you'll not screw up the tuned ckts... probably any handbook after 1970 will have a ckt fer yew... You are not looking for a high value of amplification here. You want enough to open the ears up, and to give you a nice noise figure... It is an easy devise to play with and can give you hours of fun... P.S. a 1 meg resistor gate to gnd and a 9 volt batt are a nice starting point if you wanna play today. or a diode, a cap and a 12v fil.tap off -- rat shack carries these things (Model: MPF102 FET Catalog #: 276-2062).... $1.29 a piece) ---- DigiKey wants 0.27 a piece klc Title: Re: Help with mating an HP-23A power supply to the MT-1 Cheyenne Post by: WU2D on May 30, 2007, 07:10:48 PM Ellen Thank God it works!
These types of problems are the best kind. blown or missing fuses dial string broken dirty tube sockets, jacks or plugs selenium RectumFrier Shorted or open microphone cables I scored a nice vintage stereo that "didn't work" because of a dirty on-off switch. Another common receiver failure is the speaker. "The radio don't work- Don't hera nuttin". WU2D Mike Title: Re: Help with mating an HP-23A power supply to the MT-1 Cheyenne Post by: AF9J on May 30, 2007, 08:37:09 PM Thanks Mike, AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands
I burned in the Cheyenne for about 5 hours on Sunday, since it sat unused for so long. I'm wiring up the D-104 I got for it, to the 4-pin male Amphenol plug John, W3JN gave me, as I write this. I had a heart stopping moment 15 minutes ago, when I dropped the tiny lock screw, that holds the end cap (that contains the mic pins) into the shell, into the carpet! Luckily, after some frantic searching, I found it. Well, back to wiring the mic. It looks like I'm going to have to strip some more wire, so I have enough to feed into the pins. 73, Ellen - AF9J |