[Hammarlund] HQ-215

[Bob Macklin]

Classically this is done by using the screen of the oscillator tube as the 
plate for the oscillator circuit (oscillating at the fundamental) ant then 
the real plate of the tube is tuned to the desired harmonic.

Bob Macklin
K5MYJ
Seattle, Wa.
"Real Radios Glow In The Dark"
----- Original Message ----- 
From: "rbethman" <rbethman at comcast.net>
To: <hammarlund at qth.net>
Cc: "Bob Macklin" <macklinbob at msn.com>; "Dan Cotsirilos" <k9dtc at comcast.net>
Sent: Wednesday, June 16, 2010 11:34 AM
Subject: Re: [Hammarlund] HQ-215


> The real oddball thing is that the Tuning Units for the BC-610 will either 
> use a crystal at its fundamental, the nest TU will use it, and be a 
> doubler, while a third one will use the original crystal and will be a 
> tripler.
>
> IOW - The 3Mc TU will use the 3945Kc crystal in the fundamental freq., the 
> 7Mc TU will use it and double it, and the one covering 12 Mc will triple 
> it.
>
> The oscillator circuitry has the 6V6 and 6L6 tubes to do the doubling and 
> tripling, driving a pair of 807s that push the circuitry feeding the grid 
> of the 250TH.
>
> Bob - N0DGN
>
> On 6/16/2010 2:19 PM, Bob Macklin wrote:
>> Overtone crystals are always an ODD harmonic!
>>
>> Bob Macklin
>> K5MYJ
>> Seattle, Wa.
>> "Real Radios Glow In The Dark"
>> ----- Original Message -----
>> From: "Dan Cotsirilos"<k9dtc at comcast.net>
>> To:<hammarlund at qth.net>
>> Sent: Wednesday, June 16, 2010 11:11 AM
>> Subject: [Hammarlund] HQ-215
>>
>>
>>
>>> Note of interest that maybe HQ-215 owners already know. Up until 12 mc 
>>> the
>>> HQ-215 uses the exact same crystals as the Collins S-line. I happen to
>>> have a crystal pack and the crystal freq's are the same as the 215. 
>>> After
>>> 12 mc the Collins uses double overtone and the 215 uses triple.
>>>
>>> The filters are the same 1/2 the crystals are the same triple vs double 
>>> is
>>> a funny place to make a distinction?
>>>
>>>
>>> Dan K9DTC
>
>