here are a few questions for those more knowledgeble.

1.) on the ak20c continuity table: black lead to; p1r and p2r should be none. im getting continuity here. the reasons say either no. 1,2 r.f.t. grounded, or, shorted by-pass condenser. i've checked the condenser and all is well. all of the wiring to the a.f.t. transformers seems correct. so, how do i tell if they are grounded? and what does that mean exactly, since according to the shematic,several connections to ground should occur anyway?

2.) i use an arbee111 for a power supply. while moving the aligator clip attached to the antenna lead, i accidently touched a screw on the face plate of an eletrical sockett. the clip arched with a small spark, then im now getting what sounds like 60htz hum in my set that increases as i increase filimant rheostadt. have i ruined power supply or something in radio itself?

despite the supposed grounded r.f.t's, im recieving anyway, but only loud local stations. not very selective. and sometimes get little if any reaction from tap switch, or even #1 tuning knob. is this just the state of the art for 1925, or do any of yours work better?

sorry guys, im no engineer and have had no formal training, so some of my questions mmay seem very basic. thanks for your patience.

Hi,
Are you using the official AK documentation, or are you using the Rider schematic? This is just so that we have the same nomenclature.

The Black wire, is "A-", which is the filament negative, and also is the "low" reference for the first audio stage transformer secondary. It should be isolated from the second audio stage secondary, unless you are not using a "C" battery, but performance will be lacking as a general rule. There should be no continuity with the tubes removed between the green with yellow stripe, and any other wire (also this assumes that there is no headphone, or speaker attached). If you are presently getting continuity with the tubes in place between this wire and the black wire the first audio stage tube is shorted, or there is a wire shorting underneath. If there is no tube in place, and you get continuity between the striped wire and the white wire, the second audio transformer is shorted.

The white wire is your detector stage plate voltage (7.5 volts) Both RF transformers are tied to this, so you will get a continuity reding between the white wire and the plates of the first two RF stages.

There is an official "earth ground", and it does tie to the black wire, but it is through the RF control rheostat.

On the matter of the second question, check to see that you did not burn out the coil that the antenna connects to. You should get some resistance to the earth ground. If that checks out okay, you may have damaged a filter cap in the power supply. I would just test the tubes in the radio to make sure that none were damaged just to be sure, as well as the fixed resistors too. I would also check over the antenna to make sure that it did not find something else to short to, or land near a strong magnetic field. It will ultimately be something very basic, but finding it's location will take the time.

If everything is fine, and your antenna is adequate, you should get respectable reception up to about 20-25 miles on flat land. You can pull in some distant stations if you tune carefully with a long antenna, and a good earth ground. Distant stations will be quieter, as you have no AGC (development of the thirties). If youhave one station splattering much of the tuning range, add a wave trap tuned to that frequency to attenuate it.

Also, your best reception will be at night. With a good antenna and ground, you should be able to pull in stations 500 to 700 miles distant unless you are in a valley.

: here are a few questions for those more knowledgeble.

: 1.) on the ak20c continuity table: black lead to; p1r and p2r should be none. im getting continuity here. the reasons say either no. 1,2 r.f.t. grounded, or, shorted by-pass condenser. i've checked the condenser and all is well. all of the wiring to the a.f.t. transformers seems correct. so, how do i tell if they are grounded? and what does that mean exactly, since according to the shematic,several connections to ground should occur anyway?

: 2.) i use an arbee111 for a power supply. while moving the aligator clip attached to the antenna lead, i accidently touched a screw on the face plate of an eletrical sockett. the clip arched with a small spark, then im now getting what sounds like 60htz hum in my set that increases as i increase filimant rheostadt. have i ruined power supply or something in radio itself?

: despite the supposed grounded r.f.t's, im recieving anyway, but only loud local stations. not very selective. and sometimes get little if any reaction from tap switch, or even #1 tuning knob. is this just the state of the art for 1925, or do any of yours work better?

: sorry guys, im no engineer and have had no formal training, so some of my questions mmay seem very basic. thanks for your patience.

Hello Paul,
The only way that you would get continuity on the primary side of the r.f. coils is if the condenser was shorted to ground. The primary side of the coils connect 671/2 "b" voltage and not ground. The secondary side of the coils would go to ground on the A- side.
Are you testing with the tubes removed? You shouldn't get any hum with the power supply connected. Can you back off the "A" voltages to about 4.5 volts? Sometimes this will help get rid of hum with power supplies. You should have plenty of volume with this model as I have three and I listen to the "Grand O Opry" in Nashville about 600 miles from me.

Hi Paul, You've had good replies about the AK however I'm concerned about the power supply. I don't know the particular supply but suspect it has a solid state regulator, probably either a transistor or IC series pass regulator. The ZAP may have shorted the regulator, causing it to pass the full unregulated (and poorly filtered) voltage from the rectifier. Measure its voltage, it's likely to be too high, risking damage to the tubes in your AK. If that's the case it shouldn't be a big problem to replace the damaged parts but don't operate it untill it's fixed. Shorted transformers will usually show up with an ohmeter, likely to be dead shorted across. Don Black.

: here are a few questions for those more knowledgeble.

: 1.) on the ak20c continuity table: black lead to; p1r and p2r should be none. im getting continuity here. the reasons say either no. 1,2 r.f.t. grounded, or, shorted by-pass condenser. i've checked the condenser and all is well. all of the wiring to the a.f.t. transformers seems correct. so, how do i tell if they are grounded? and what does that mean exactly, since according to the shematic,several connections to ground should occur anyway?

: 2.) i use an arbee111 for a power supply. while moving the aligator clip attached to the antenna lead, i accidently touched a screw on the face plate of an eletrical sockett. the clip arched with a small spark, then im now getting what sounds like 60htz hum in my set that increases as i increase filimant rheostadt. have i ruined power supply or something in radio itself?

: despite the supposed grounded r.f.t's, im recieving anyway, but only loud local stations. not very selective. and sometimes get little if any reaction from tap switch, or even #1 tuning knob. is this just the state of the art for 1925, or do any of yours work better?

: sorry guys, im no engineer and have had no formal training, so some of my questions mmay seem very basic. thanks for your patience.