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#11
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On 2/2/2016 10:24 AM, Scott Dorsey wrote:
Jerry Stuckle wrote: I've had a lot of fun in as a ham in the last 48 years, but I don't think anything will compare with the QSO's I made as a novice with a crystal rig and dipole. Well, for God's sake, put down $20, build a Tuna Tin Two, and get on the air again! I am running 5W with a homebrew compactron-based VFO and having a blast. --scott I still enjoy CW - but nothing will ever compare to the excitement of those first contacts as a novice, even if I had my old Hallicrafters SX-43 and Knight-kit T-60 back again! I made a lot of QSO's with a 40M dipole stretched across my parents back yard. Only about 15' above ground, but it worked. I've had better antennas which got farther and had better signal reports. But none worked as well as that dipole! ![]() -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
#12
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On 02/02/2016 09:56 AM, Jerry Stuckle wrote:
On I still enjoy CW - but nothing will ever compare to the excitement of those first contacts as a novice, even if I had my old Hallicrafters SX-43 and Knight-kit T-60 back again! I made a lot of QSO's with a 40M dipole stretched across my parents back yard. Only about 15' above ground, but it worked. I've had better antennas which got farther and had better signal reports. But none worked as well as that dipole! ![]() One of my best contacts was working Ascension Island (from Wisconsin) on 40 meter CW with a wire vertical. I was running 50 watts. Eventually I put up a beam, but was anxious to use it and worked South Africa with it on the tripod just 3 or 4 feet off the ground |
#13
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In article ,
analogdial wrote: hilo wrote: Thanks for the great explanation! As "analogdial" pointed out, it's actually an S 36 I did not examine the photos carefully enough The S-36 has a panadaptor connection on the back of the chassis. Altough I don't think it was often used. It does? I don't see that in the schematic on bama. Also, the IF frequency on the S-27/S-36/S-36A is 5250 Kc, not 455 or near there. So it would require a different panadapter, intended for use at that frequency. I had, for several years an S-36A, which is almost, but not quite, the same as as the non-A version. The S-27 prewar original was also not all that different until you got into the detectors and audio (used different tubes). It's a mediocre radio by today's standards. Not particularly sensitive and the narrow bandwidth is way too wide for just one AM channel. The wide bandwidth is a bit too narrow for fully modulated broadcast FM but it wasn't too bad back in the day when some FMers broadcast with SCA. Worked well for TV FM audio. The audio was very good. I tried stagger tuning the IF transformers for wider bandwidth but that hurt the sensitivity on wide and nearly killed it on narrow. The damn thing was built to last. There's only one paper capacitor, in the power supply filter. 8 ufd of paper in a sealed steel can, if i recall. It's huge. I checked mine for leakage and it was still no worse than an equivelant electrolytic, so I left it alone. There's also one electrolytic (also in steel, looks like an oil and paper, mine was no good) for the cathode bypass in the audio amp. Everything else is silver mica. The resistors checked out 100%. Didn't look like any under chassis work had ever been done on the radio. Amazing. It has a really nice zero backlash gear drive. Probably the nicest thing about the radio. Yes, it was "quite the radio" for its day. I spent a good deal of time on my set. In general, on the lower two bands it had reasonably good sensitivity and performance, but really got into trouble on the third (highest) band, which started at the audio carrier for TV channel 6 (postwar). That IF frequency was neither fish nor fowl---too low for postwar commercial FM signals with 75 Khz deviation. As I recall, postwar FM receivers with 10.7 Mhx IF's have a bandpass of 200 Khz or more, but with the S-36A, I couldn't find a way to get flat response much above 160 Khz. That meant that tuning was very critical. I tried loading resistors and staggered tuning, but both just killed performance without broadening the bandpass that much. I had the IF transformers out of the set so that I could check the coils on a Boonton 260A Q meter and a 250A RX meter. The IF's are slug-tuned, and one section of one of them simply did not tune with its slug. Rather than fuss too much with it, I simply replaced the fixed capacitor in the can with a lower value and hung a trimmer outside across the terminals. The 250A let me determine the values and pretune the IF's before I reinstalled them. I see from the schematic that the plain 36 used trimmers rather than slugs for IF tuning. The RF front end on my set when I got it was a mess. I took the assembly out and took most of it apart to get it cleaned up. Once again, the Boonton 250A and 260A were a great help in "getting the Q back." One important thing about the S-27/36 is that it uses low oscillator on band 3, but high on the other two bands. One comment in the above discsussion, about a bypass cap in the output tube cathode circuit, puzzled me. The S-36A did not have one, but I see one in the non-A and S-27 schematics. Leaving that cap out aids push-pull linearity, as any imbalance causes the high-gain tube to act as a cathode follower driving the other half as a grounded-grid amplifier. That configuration is at the core of a lot of Tektronix vertical amplifier circuits. The audio on this radio was incredibly good. The specs talk about 10 Khz at the high end, but my set would pass closer to 20 before it hit 6db (voltage) down. The FM deemphasis filter installed in the set was the prewar value---100 microseconds, as I recall. Changed that to the postwar 75 microsecond values. Yes, the tuning mechanicals on that set were very nice. That was **after** I took it all apart, cleaned and relubricated it, and replaced all the balls with new ones from a bearing supply place. That was about 25 years ago, so I've probably forgotten some things. As a radio, it was an interesting foray into studying 1940 state-of-the-art as well as quite impressive-looking. But compared to even early postwar designs, the set simply fell flat on its face at around 100 Mhz---not particularly sensitive, poor image rejection, and either too broad on AM or too narrow on FM. As I recall, that set ended up (with an early stereo converter) in the lobby of a non-com classical station as a lobby monitor. Hank |
#14
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Hank wrote:
The S-36 has a panadaptor connection on the back of the chassis. Altough I don't think it was often used. It does? I don't see that in the schematic on bama. Also, the IF frequency on the S-27/S-36/S-36A is 5250 Kc, not 455 or near there. So it would require a different panadapter, intended for use at that frequency. Mine does. It's a SO 239 connector, marked PAN, on a bakelite panel beside the antenna binding posts and a another oddball coaxial connector. It looks original although I suppose it could be a repair depot mod. Doesn't look like a ham mod. Don't remember what the oddball connector is for. It's not marked. I had, for several years an S-36A, which is almost, but not quite, the same as as the non-A version. The S-27 prewar original was also not all that different until you got into the detectors and audio (used different tubes). It's a mediocre radio by today's standards. Not particularly sensitive and the narrow bandwidth is way too wide for just one AM channel. The wide bandwidth is a bit too narrow for fully modulated broadcast FM but it wasn't too bad back in the day when some FMers broadcast with SCA. Worked well for TV FM audio. The audio was very good. I tried stagger tuning the IF transformers for wider bandwidth but that hurt the sensitivity on wide and nearly killed it on narrow. The damn thing was built to last. There's only one paper capacitor, in the power supply filter. 8 ufd of paper in a sealed steel can, if i recall. It's huge. I checked mine for leakage and it was still no worse than an equivelant electrolytic, so I left it alone. There's also one electrolytic (also in steel, looks like an oil and paper, mine was no good) for the cathode bypass in the audio amp. Everything else is silver mica. The resistors checked out 100%. Didn't look like any under chassis work had ever been done on the radio. Amazing. It has a really nice zero backlash gear drive. Probably the nicest thing about the radio. Yes, it was "quite the radio" for its day. I spent a good deal of time on my set. In general, on the lower two bands it had reasonably good sensitivity and performance, but really got into trouble on the third (highest) band, which started at the audio carrier for TV channel 6 (postwar). That IF frequency was neither fish nor fowl---too low for postwar commercial FM signals with 75 Khz deviation. As I recall, postwar FM receivers with 10.7 Mhx IF's have a bandpass of 200 Khz or more, but with the S-36A, I couldn't find a way to get flat response much above 160 Khz. That meant that tuning was very critical. I tried loading resistors and staggered tuning, but both just killed performance without broadening the bandpass that much. Yeah, I was hoping that an alignment with a sweep generator and a scope would allow for full FM bandwidth and some drift. Didn't work out and it's never been an "active" radio for me. I had the IF transformers out of the set so that I could check the coils on a Boonton 260A Q meter and a 250A RX meter. The IF's are slug-tuned, and one section of one of them simply did not tune with its slug. Rather than fuss too much with it, I simply replaced the fixed capacitor in the can with a lower value and hung a trimmer outside across the terminals. The 250A let me determine the values and pretune the IF's before I reinstalled them. I see from the schematic that the plain 36 used trimmers rather than slugs for IF tuning. The RF front end on my set when I got it was a mess. I took the assembly out and took most of it apart to get it cleaned up. Once again, the Boonton 250A and 260A were a great help in "getting the Q back." One important thing about the S-27/36 is that it uses low oscillator on band 3, but high on the other two bands. One comment in the above discsussion, about a bypass cap in the output tube cathode circuit, puzzled me. The S-36A did not have one, but I see one in the non-A and S-27 schematics. Leaving that cap out aids push-pull linearity, as any imbalance causes the high-gain tube to act as a cathode follower driving the other half as a grounded-grid amplifier. That configuration is at the core of a lot of Tektronix vertical amplifier circuits. I didn't notice any difference in the sound with the new cap. The audio on this radio was incredibly good. The specs talk about 10 Khz at the high end, but my set would pass closer to 20 before it hit 6db (voltage) down. The FM deemphasis filter installed in the set was the prewar value---100 microseconds, as I recall. Changed that to the postwar 75 microsecond values. Yes, the tuning mechanicals on that set were very nice. That was **after** I took it all apart, cleaned and relubricated it, and replaced all the balls with new ones from a bearing supply place. The gear drive was working well except the ball retainer on the knob shaft bearing had fallen apart. I got some extra balls and put them in, one ball less than tight. Worked perfectly. The gear drive was in good shape but I took on the challenge of disassembling and cleaning it. My habit of looping a long piece of thread through the springs saved me some trouble. That was about 25 years ago, so I've probably forgotten some things. As a radio, it was an interesting foray into studying 1940 state-of-the-art as well as quite impressive-looking. But compared to even early postwar designs, the set simply fell flat on its face at around 100 Mhz---not particularly sensitive, poor image rejection, and either too broad on AM or too narrow on FM. As I recall, that set ended up (with an early stereo converter) in the lobby of a non-com classical station as a lobby monitor. Hank |
#15
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On 02/04/2016 11:19 PM, Hank wrote:
In article , analogdial wrote: snipped for brevity That was about 25 years ago, so I've probably forgotten some things. As a radio, it was an interesting foray into studying 1940 state-of-the-art as well as quite impressive-looking. But compared to even early postwar designs, the set simply fell flat on its face at around 100 Mhz---not particularly sensitive, poor image rejection, and either too broad on AM or too narrow on FM. As I recall, that set ended up (with an early stereo converter) in the lobby of a non-com classical station as a lobby monitor. Hank Wow, great account! I never had much test equipment so simply tuned to a weak signal and tweaked "by ear" as best as possible. As to working on transmitters, we always joked: Tune for minimum smoke! |
#16
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In message , philo
writes On 02/04/2016 11:19 PM, Hank wrote: In article , analogdial wrote: snipped for brevity That was about 25 years ago, so I've probably forgotten some things. As a radio, it was an interesting foray into studying 1940 state-of-the-art as well as quite impressive-looking. But compared to even early postwar designs, the set simply fell flat on its face at around 100 Mhz---not particularly sensitive, poor image rejection, and either too broad on AM or too narrow on FM. As I recall, that set ended up (with an early stereo converter) in the lobby of a non-com classical station as a lobby monitor. Hank Wow, great account! I never had much test equipment so simply tuned to a weak signal and tweaked "by ear" as best as possible. As to working on transmitters, we always joked: Tune for minimum smoke! "Minimum"? You'll never work any DX doing that! -- Ian |
#17
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On 02/07/2016 07:38 AM, Ian Jackson wrote:
ow, great account! I never had much test equipment so simply tuned to a weak signal and tweaked "by ear" as best as possible. As to working on transmitters, we always joked: Tune for minimum smoke! "Minimum"? You'll never work any DX doing that! I did not want to burn out my 807 OTOH: When ten meters is open, two watts (or less) can do the job |
#18
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On 2/7/2016 10:42 AM, philo wrote:
On 02/07/2016 07:38 AM, Ian Jackson wrote: ow, great account! I never had much test equipment so simply tuned to a weak signal and tweaked "by ear" as best as possible. As to working on transmitters, we always joked: Tune for minimum smoke! "Minimum"? You'll never work any DX doing that! I did not want to burn out my 807 OTOH: When ten meters is open, two watts (or less) can do the job Now that hurts, nostalgically! I started out with a pair of 1625's (807's with 12V filaments) in a military surplus xmtr I converted... That was in 1957. I wish I had it back now! Bob Wilson |
#19
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In message , Bob Wilson
writes On 2/7/2016 10:42 AM, philo wrote: On 02/07/2016 07:38 AM, Ian Jackson wrote: ow, great account! I never had much test equipment so simply tuned to a weak signal and tweaked "by ear" as best as possible. As to working on transmitters, we always joked: Tune for minimum smoke! "Minimum"? You'll never work any DX doing that! I did not want to burn out my 807 OTOH: When ten meters is open, two watts (or less) can do the job Now that hurts, nostalgically! I started out with a pair of 1625's (807's with 12V filaments) in a military surplus xmtr I converted... That was in 1957. I wish I had it back now! Bob Wilson TCS xx TX? I still have a TCS10. -- Ian |
#20
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On 02/07/2016 01:44 PM, Bob Wilson wrote:
On 2/7/2016 10:42 AM, philo wrote: On 02/07/2016 07:38 AM, Ian Jackson wrote: ow, great account! I never had much test equipment so simply tuned to a weak signal and tweaked "by ear" as best as possible. As to working on transmitters, we always joked: Tune for minimum smoke! "Minimum"? You'll never work any DX doing that! I did not want to burn out my 807 OTOH: When ten meters is open, two watts (or less) can do the job Now that hurts, nostalgically! I started out with a pair of 1625's (807's with 12V filaments) in a military surplus xmtr I converted... That was in 1957. I wish I had it back now! Bob Wilson Here I am in my shack 50 years ago https://www.dropbox.com/s/5usk3tqswj...hack1.JPG?dl=0 |
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